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VOL 82 (2017)
COMMUNICATIONS IN AGRICULTURAL AND APPLIED BIOLOGICAL SCIENCES
Formerly known as
MEDEDELINGEN FACULTEIT LANDBOUWKUNDIGE EN TOEGEPASTE BIOLOGISCHE WETENSCHAPPEN
Publishers
PROF. GUY SMAGGHE PROF. STEVEN SLEUTEL
DR. JAN BAETENS PROF. EVELINE VOLCKE
Editorial address
Coupure links 653 9000 Gent (Belgium)
ISSN 1379-1176
The results published in this book of abstracts are under the full responsibility of the authors. The organizing committee cannot be held responsible for any errors in this publication and potential consequences thereof.
ii
PROCEEDINGS
22ND NATIONAL SYMPOSIUM ON
APPLIED BIOLOGICAL SCIENCES
FACULTY OF BIOSCIENCE ENGINEERING
KU LEUVEN FEBRUARY 7TH, 2017
Website
www. nsabs2017.be
i
ORGANIZING COMMITTEE KU Leuven – host institute 2017: Barbara De Coninck, Bram Van den Bergh, Eline Vanuytrecht, Liesbeth François, Mariya Petrova and all the volunteers of the (FR)ACTIE association Universiteit Antwerpen: Dieter Vandenheuvel, Jelle Hofman Universiteit Gent: Jan Baetens, Chris Callewaert, Caroline Van der Heyden Vrije Universiteit Brussel Julien Cousin Saint Remi, Kris Pauwels, Wim De Malsche Université Catholique de Louvain Valentin Couvreur, Xavier Draye, Gauthier Lequeue Université de Liège: Hélène Soyeurt, Jérôme Bindelle Université Libre de Bruxelles: Christian Hermans REVIEWER COMMITTEE KU Leuven: Barbara De Coninck, Bram Van den Bergh, Eline Vanuytrecht, Liesbeth François, Mariya Petrova, Trees De Baerdemaeker, Niels De Brier Universiteit Antwerpen: Ingmar Claes, Jelle Hofman, Tom Tytgat, Dieter Vandenheuvel, Erik Van Eynde, Sammy Verbruggen, Karen Wuyts Universiteit Gent: Jan Baetens, Chris Callewaert, Caroline Van der Heyden, Aisling Daly, Michiel Stock, Steffie Van Nieuland Université Catholique de Louvain: Valentin Couvreur, Sixtine Passot, Gauthier Lequeue Université de Liège: Hélène Soyeurt, Jérôme Bindelle, Angélique Léonard, Jean-Micel Romuee, Benoit Mercatoris, Magali Deleu, Georges C. Lognay, Université Libre de Bruxelles: Vrije Universiteit Brussel Julien Cousin Saint Remi, Kris Pauwels, Wim De Malsche, Damya Laoui, Yann Sterckx Diagenode Geoffrey Berguet
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ACADEMIC SUPPORT The National Symposium on Applied Biological Sciences (NSABS2017) is jointly organized by the following institutes:
- Faculty of Bioscience Engineering, KU Leuven - Department of Bioscience Engineering, University of Antwerp - Faculty of Bioscience Engineering, Gent University - Faculty of Bioscience Engineering, Université Catholique de Louvain - Earth and Life Institute, Université Catholique de Louvain - Université Libre de Bruxelles - Université de Liège - Faculty of Scince and Bioscience Egineering, Vrije Universiteit Brussel
WEBSITE www.nsabs2017.be ACADEMIC AND GOVERNMENTAL FINANCIAL SUPPORT The organizing committee of NSABS2017 is grateful for the financial and logistic support by the following institutes and their doctoral schools:
- KU Leuven - UAntwerp - VUB - UGent - ULB - UCL - ULg - UGent Doctoral Schools (Bioscience) Engineering - YouReCa - FNRS Graduate School on Environmental Sciences, Technologies and Management
(ENVITAM) - FNRS Graduate School on Agricultural Sciences and Biological Engineering (EDT-SCAIB) - FNRS Graduate School in Plant Sciences - Vlaamse overheid - Vlaanderen in Actie - Richting Morgen (Vlaamse overheid)
ENVITAM
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INDUSTRIAL SPONSORS
The NSABS2017 organizing committee is extremely grateful for the financial support received from VWR:
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PROGRAM
22nd NATIONAL SYMPOSIUM ON APPLIED BIOLOGICAL SCIENCES
08.30-09.10
Registration
09.10 – 09.20
Welcome
(Aula BMW1- ON2 04.223)
09.20 – 10.05
First keynote talk – Prof. Kevin Verstrepen, KU Leuven & VIB
“Generating superior industrial yeasts”
(Aula BMW1- ON2 04.223)
10.05 – 10.50
Second keynote talk – Dr. An Michiels, Global Head of Research Bayer CropScience Vegetables
“Innovitation”
(Aula BMW1- ON2 04.223)
10.50 – 11.15
Coffee break
(Foyer)
11.15 – 12.55
Thematic parallel oral presentations
(Aula BMW1, Aula BMW3, Aula BMW4)
12.55 – 14.15
Poster session and lunch break
(Foyer)
14.15 – 16.15
Thematic parallel oral presentations
(Aula BMW1, Aula BMW3, Aula BMW4)
v
16.15 – 17.15
Poster seesion and coffee break
(Foyer)
17.15 – 17.30
Closing remarks and awards
(Aula BMW1- ON2 04.223)
17.30 – … Network reception
(Foyer)
vi
THEMATIC PARALLEL ORAL PRESENTATIONS
Session 1.1: Food technology and Industrial Microbiology p. 1
Chair: Abram Aertsen (Aula BMW1 - ON2 04.223)
11.15-11.35 Impact of storage factors on colour changes of pasteurised strawberry juice: a kinetic study. Carolien Buvé (KU Leuven)
11.35-11.55 Screening of rheological properties of various microalgae species towards their application in food products Tom Bernaerts (KU Leuven)
11.55-12.15 The role of acetic acid bacteria in lambic beer production processes is underestimated Jonas De Roos (VUB)
12.15-12.35 Exploring Dunaliella salina as single cell protein (SCP): the influence of light/dark regime on the growth and protein synthesis Yixing Sui (UAntwerp)
12.35-12.55 Evolution of the metabolite profiles of coffee beans under various post-harvest processing methods Sophia Jiyuan Zhang (VUB)
Session 1.2: Environment and Agriculture p. 10
Chair: Xavier Draye (Aula BMW3 - ON2 04.216)
11.15-11.35 Is soil pore structure control on substrate decomposition manifested through N availability? Peter Maenhout (UGent)
11.35-11.55 Partitioning selection and complementarity effects to understand overyielding in tree diversity experiments Thomas Van de Peer (KU Leuven)
11.55-12.15 Iron coated sand/glauconite filters for phosphorus removal from artificially drained agricultural fields Stany Vandermoere (UGent)
12.15-12.35 Tunisian dairy farmers’ perceptions of climate change impacts and options for adaptation Hajer Amamou (ULg)
vii
12.35-12.55 Extraction and connection of artificial drainage networks in agricultural areas using LiDAR data Jennifer Roelens (KU Leuven)
Session 1.3: Chemistry and Engineering p. 16 Chair: Wim De Malsche (Aula BMW4 - ON2 04.212)
11.15-11.35 Cu-Ni pyrazolate frameworks as heterogeneous catalysts for the synthesis of neuroactive molecules Francisco García Cirujano (KU Leuven)
11.35-11.55 A study of the ZIF-8 zeolitic imidazolate framework as adsorbent for volatile organic compounds detection and removal Thomas Virdis (VUB)
11.55-12.15 Spatio-temporal modelling of filter cake formation in filtration processes Bram De Jaegher (UGent)
12.15-12.35 Peak deconvolution to correctly and completely sssess the true band broadening of chromatographic columns Yoachim Vanderheyden (VUB)
12.35-12.55 Design and evaluation of a miniaturized microfluidic platform for ion-exchange chromatography Sam Wouters (VUB)
Session 2.1: Food technology and Industrial Microbiology p. 24
Chair: Jéroeme Bindelle (Aula BMW1 - ON2 04.223)
14.15-14.35 Viscoelastic properties of high pressure homogenised citrus fibre fractions obtained after sequential pectin extraction Katleen Willemsen (KU Leuven)
14.35-14.55 Role of degree and pattern of methylesterification on Fe2+ adsorption capacity of citrus pectin Miete Celus (KU Leuven)
14.55-15.15 Exploring the microbiota associated with green coffee bean production Florac De Bruyn (VUB)
15.15-15.35 Influence of oil type on in vitro lipid digestion and carotenoid bioaccessibility: a kinetic study Sarah Verkempinck (KU Leuven)
viii
15.35-15.55 The influence of citrate in type II sourdough fermentations initiated with a citrate-positive lactic acid bacterial starter culture Andrea Comasio (VUB)
15.55-16.15 Towards upgrading of wastewater resources to microbial protein: Volatile fatty acids impacting growth kinetics and yield of purple bacteria Abbas Alloul (UAntwerp)
Session 2.2: Environment and Agriculture p. 31
Chair: Bram Van De Poel (Aula BMW3 - ON2 04.216)
14.15-14.35 Flemish policy tackling agricultural ammonia emissions: still room for improvement David De Pue (UGent)
14.35-14.55 Does replacing grass silage by maize silage in Flemish dairy cattle diets lead to methane reduction? Dorien Van Wesemael (UGent)
14.55-15.15 Ecological water quality and threshold responses of macroinvertebrate communities to stream velocity in the Guayas River basin (Ecuador) Thi Hanh Tien Nguyen (UGent)
15.15-15.35 Development and validation of an UHPLC-ESI-MS/MS method to quantify estrogenic compounds as pyridine-3-sulfonyl derivatives in aqueous matrices Alex Glineur (ULg)
15.35-15.55 Emerging threats to Ugandan honeybees, pilot study reveals presence of pesticides and honeybee pathogens Deborah Ruth Amulen (UGent)
15.55-16.15 Contrasting vulnerability and resilience to drought-induced defoliation in mixed versus pure stands. Ana Rita Silva (KU Leuven)
Session 2.3: Human health and Genomics and biotechnology p. 38 Chair: Mariya Petrova (Aula BMW4 - ON2 04.212)
14.15-14.35 Functional and structural elucidation of a ssDNA-binding protein encoded by the N4-like, Pseudomonas phage LUZ7 Maarten Boon (KU Leuven)
14.35-14.55 Intrinsically disordered proteins – extraordinary protein functions and novel method for their detection Nevena Hristozova (VUB)
14.55-15.15 HokB, a pore-forming toxin, induces persistence after dimerization Dorien Wilmaerts (KU Leuven)
ix
15.15-15.35 Nanobody-based depletion of protumoral tumor-associated macrophages as novel cancer therapy Evangelia Bolli (VUB)
15.35-15.55 Akkermansia muciniphila colonization of an in vitro distal colon is largely mucin and pH dependent Florence Van Herreweghen (UGent)
15.55-16.15 Revealing the role of TBC1D24 mutations in epilepsy Jone Paesmans (VUB)
1
Lecture session 1.1
FOOD TECHNOLOGY AND INDUSTRIAL MICROBIOLOGY
2
IMPACT OF STORAGE FACTORS ON COLOUR CHANGES OF PASTEURISED STRAWBERRY JUICE: A KINETIC STUDY
Carolien Buvé*, Biniam Kebede*, Cédric De Batselier*, Celia Carrillo Pérez**, Huong Pham*,
Marc Hendrickx*, Tara Grauwet* and Ann Van Loey*
*KU Leuven, Belgium; ** University of Burgos, Spain
An attractive colour is one of the most important food quality attributes determining
consumers’ acceptance and purchase behaviour of food products. Unfortunately, processing and
mainly storage negatively affect colour and thereby product acceptability. Literature data show that
colour loss results from the simultaneous degradation of natural pigments (e.g. anthocyanins) and
formation of brown compounds through different pathways (e.g. ascorbic acid (AA) degradation). For
fruit-based shelf-stable products, browning is a quality handicap determining the shelf-life of these
products. Nevertheless, insight into the effect of storage on colour changes in fruit-based products is
still limited.
In the present work, the effect of three relevant storage factors (storage time and
temperature, and oxygen availability) on changes in colour related-attributes (CIELAB values,
anthocyanin and AA content) of pasteurised strawberry juice was studied quantitatively. For this
purpose, an accelerated shelf-life test (ASLT), in which pasteurised strawberry juice was stored at
ambient and abuse temperatures (20 42°C) in two types of bottles with different oxygen
permeability, was performed. The redness, the anthocyanin and AA content decreased, while the
total colour difference increased significantly during storage. The change in all attributes was
accelerated at higher temperatures, as quantified through the activation energy. A higher oxygen
availability also resulted in a faster change of the attributes during storage. Different pathways seem
to contribute to the browning of strawberry juices during storage and interactions between
compounds or pathways should not be overlooked when explaining colour changes in juices.
Furthermore, this work shows the potential of ASLT in combination with kinetics to study, predict and
evaluate quality changes during storage and to optimize storage conditions of strawberry juices to
guarantee food quality and minimise food waste.
3
SCREENING OF RHEOLOGICAL PROPERTIES OF VARIOUS MICROALGAE SPECIES TOWARDS THEIR APPLICATION IN FOOD PRODUCTS
Tom Bernaerts*, Agnese Panozzo*, Veerle Doumen*, Imogen Foubert**, Lore Gheysen**,
Koen Goiris***, Paula Moldenaers*, Marc Hendrickx* and Ann Van Loey*
*KU Leuven, Belgium; ** KU Leuven, KULAK, Belgium;
*** KU Leuven Technology Campus Ghent, Belgium
Microalgae are considered as an interesting source of several health beneficial components
and nutrients, including omega-3 long chain polyunsaturated fatty acids, proteins and antioxidants.
To date, intensive research is carried out towards extraction of individual components from
microalgae. However, using the complete microalgal biomass in food products might be an
innovative strategy to utilize other functional components from microalgae. Microalgal cell wall
polysaccharides could for instance play a structuring role in food products, allowing microalgal
biomass to be used as a multifunctional ingredient.
To date, structuring properties of microalgae are only very limitedly described in literature.
Therefore, this study comprises a screening of the rheological characteristics of different microalgae
species (Chlorella, Nannochloropsis, Odontella, Phaeodactylum, Porphyridium, Schizochytrium and
Spirulina). Aqueous model systems were prepared at both pH 4 and 6, simulating fruit and vegetable
based products respectively. Mechanical and thermal processing were applied, treatments that are
commonly used in food processing. The effect of processing was investigated on both rheological
properties and microstructure of the microalgal suspensions.
The obtained results showed substantial differences in rheological properties between the
different microalgae species. The impact of mechanical processing was largely depending on the type
of microalga, while thermal processing mostly resulted in structure build-up. Changes in flow
behavior after processing could be related to both particle characteristics and serum viscosity. The
results of this study show the great potential of microalgal biomass towards food applications.
Whereas some microalgae species can be used to introduce health beneficial components without
disturbing the structure of the food matrix, other species displayed interesting thickening properties
for use as a multifunctional ingredient in food products.
4
THE ROLE OF ACETIC ACID BACTERIA IN LAMBIC BEER PRODUCTION PROCESSES IS UNDERESTIMATED
Jonas De Roos,* Stefan Weckx*, Peter Vandamme* and Luc De Vuyst*
* Vrije Universiteit Brussel, Belgium
Lambic beers are spontaneously fermented and matured (wooden casks) for 3 years. Earlier
studies reported a transient occurrence and limited role of acetic acid bacteria (AAB). Moreover, the
techniques that were used in these studies are outdated and have a low throughput compared to
nowadays’ techniques. Aseptic sampling at different heights, improved cultivation and matrix-
assisted laser desorption-ionization time-of-flight mass spectrometry (MALDI-TOF MS) identification
of 2000 isolates, and metabolomic analysis allowed investigation of the spatial distribution of
microbiota and metabolites. Two casks filled with the same wort were studied. This multiphasic
temporal approach enabled mapping of the microbial community dynamics and metabolite kinetics.
The temporal microbial and metabolite composition of both casks was complex, yet strikingly similar
over time. Four distinctive phases could be distinguished: an Enterobacteriaceae and AAB phase
(dominated by Klebsiella spp. and Acetobacter orientalis), a main yeast fermentation phase
(dominated by Saccharomyces cerevisiae), an acidification phase due to lactic acid bacteria
(dominated by Pediococcus damnosus) and AAB growth (dominated by Acetobacter pasteurianus),
and a maturation phase (dominated by Brettanomyces bruxellensis and P. damnosus). It was
interesting to notice that different AAB species were present during the first and third phase of the
production process. They contributed to the production of acetic acid (both phases) and acetoin and
ethyl acetate (third phase). The different spatial sampling points in the casks revealed small but
unmistakable differences in microbial and metabolite composition. In particular, higher AAB counts
and higher concentrations of acetic acid were present at the air/liquid interface at certain time
points. These data indicate that the occurrence and functional role of AAB during the lambic beer
production process were underestimated in the past.
5
EXPLORING DUNALIELLA SALINA AS SINGLE CELL PROTEIN: THE INFLUENCE OF LIGHT/DARK REGIME ON THE GROWTH AND PROTEIN SYNTHESIS
Yixing Sui* and Siegfried Vlaeminck*
* Research Group of Sustainable Energy, Air and Water Technology, Department of Bioscience
Engineering, University of Antwerp, Belgium
INTRODUCTION
Single cell protein (SCP), or originally named microbial protein, is the edible microbial biomass
derived from e.g. microalgae, bacteria and fungi, which can be used as protein sources replacing
conventional protein sources for animal feed or human food such as fishmeal and soybean
(Anupama & Ravindra 2000). SCP presents great potential as protein supplement to alleviate the
problem of food scarcity in the future (Nasseri et al. 2011). In general, microalgae as SCP contains
above 50% protein over dry weight and specifically for the marine microalgae Dunaliella salina the
amount stays around 57% (Becker 2007). Commercially the most common system for Dunaliella sp.
production is the outdoor open pond, thus the microalgal cells are subjected to a natural light/dark
cycle (Hosseini Tafreshi & Shariati 2009). Being photo-autotrophic microorganisms, the lack of light
energy sources is a risk leading to night biomass loss (Ogbonna & Tanaka 1996). On the other hand,
for some microalgae species cell division occurs primarily during the night suggesting its night
protein synthesis (Cuhel et al. 1984). As a consequence, day and night metabolisms of microalgae
introduced by light/dark cycles potentially will have big impacts on the biomass development, both
in growth and biochemical composition. In this study, the effect of the light/dark cycle on the growth
and protein synthesis of Dunaliella salina was explored in comparison with continuous light
cultivation.
MATERIAL AND METHODS
Microalgal strain and cultivation conditions
Green microalgae Dunaliella salina (184.80) was obtained from SAG, Culture Collection of
Algae at Göttingen University, Germany. Modified Johnson's medium (Borowitzka 1988) was used for
cultivation, replacing NaCl with table salt (Everyday, Colruyt Belgium) at 117g/L. Erlenmeyer flasks of
500mL containing 400mL microalgal suspension were used for cultivation at a constant temperature
of 20 °C, pH of 7.5 and light intensity of ±55 µmol/m2/s respectively. Mixing was achieved by placing
the flasks on a multipoint magnetic stirrer (Thermal Fisher Scientific, Cimarec™ Poly15) at 200 rpm
and carbon was supplied by sparging air with an air pump (TetraTech®, APS100) at 4.12 vvm into the
individual flasks through a serological pipet (VWR International).
Growth under 24h continuous light and 12h/12h light/dark cycle
6
In total 6 Erlenmeyer flasks were used for cultivation, of which 3 under 24h continuous light
and 3 under 12h/12h light/dark cycle as triplicates. For all flasks, the initial concentration of
Dunaliella salina suspension was equally at 0.027 OD unit at 680nm (OD680). Samples were taken
twice per day for analyses and then stored at -20 °C. Data of algal growth were presented in both
OD680 and cell number which were calculated in their common logarithm: 𝑙𝑜𝑔$%(𝑋/𝑋%) where X
and X0 are the OD680 or cell number of time X and time initial respectively. Based on the obtained
growth curve, the specific growth rate (µ) was calculated by carefully selecting two time points (T1
and T2) with their corresponding OD unit (X1 and X2) at exponential phase and following equation:
µ(𝑑-$) = (𝐿𝑛𝑋1 − 𝐿𝑛𝑋$)/(𝑇1 − 𝑇$).
Analytical methods
OD680 was measured with a UV-VIS Spectrophotometer (UV-2501PC, Shimadzu). The biomass
ash free dry weight (AFDW) was evaluated with a pre-defined correlation with OD680 following
equation: 𝐴𝐹𝐷𝑊(𝑔 𝐿⁄ ) = 𝑂𝐷:;% ∗ 0.5069 − 0.0131. Total cell numbers were determined with a
Multisizer 3 Coulter Counter (Beckman Coulter). To determine the total crude protein content the
Markwell method (Markwell et al. 1978) was used.
RESULTS AND DISCUSSION
Growth of Dunaliella salina under continuous light and 12h/12h light/dark cycle
To investigate the effect of light/dark cycle on the growth of Dunaliella salina, cultures were
exposed to two different illumination strategies, both continuous light and 12h/12h light/dark cycle.
The corresponding curves are shown in Figure 1. Cultures under two different illumination strategies
showed clearly different growth curves over 700-hour cultivation but both presented clear growth
stages of lag phase (data not shown), exponential phase, decelerating phase, stationary phase and
declining phase. Cultures under continuous light had a growth rate of 0.456 d-1 reaching a final
biomass concentration of 1.364 gAFDW/L while cultures under 12h/12h light/dark cycle showed a
20% slower growth rate of 0.364 d-1 reaching 40% less biomass concentration of 0.813 gAFDW/L.
Being obligate photoautotrophic microalgae, Dunaliella salina evidently requires light to support the
growth (Borowitzka L.J. and Borowitzka M.A. 1989) and without light source both growth rate and
biomass concentration will reduce correspondingly. When comparing the growth pattern followed by
OD680 and cell number, it is interesting to see that OD680 and cell number overlaps each other well
before late exponential phase, however diverges fairly afterwards. The difference is mainly because
the biomass at late growth stage contains both living cells and residual cell debris. This implies a
difference between cell number and biomass when demonstrating results. Thus wisely and correctly
choosing parameters to demonstrate experimental results is highly important.
7
Figure 1 Growth of D. salina under continuous light (CL) and 12h/12h light/dark (LD) cycle followed by both OD680 and cell number. The cultivation was at temperature 20°C and light intensity ~55 µmol/m2/s with continuous mixing at 200 rpm. Figures are shown in means ± standard deviation.
Protein synthesis of Dunaliella salina under continuous light and 12h/12h light/dark cycle
Protein synthesis of microalgae is one of the most vital mechanisms in their growth. Samples
from different growth stages of both continuous light and 12h/12h light/dark cycle were collected for
crude protein analysis as shown in
Figure 2. In general, protein built-up and decline pattern of Dunaliella salina biomass varies
from its growth pattern. Evident increase of protein content up to 80% of its AFDW appeared at the
end of exponential phase. Nevertheless the biomass concentration at this stage was merely around
0.4 gAFDW/L. Protein content declined eventually to 62% of its AFDW despite the continuing
biomass growth. In photosynthetic microalgae, high protein and low carbohydrate content are
generally the main characteristics of rapidly growing cells (Zhu et al. 1997). However, when growth
limiting factors occur such as nutrient and/or light, lower protein and higher carbohydrate content
will be realised, typically in the stationary phase of their growth (Zhu et al. 1997; Fidalgo et al. 1998).
0.0
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8
On the other hand, in spite of the varied growth rate under both continuous light and 12h/12h
light/dark cycle, their protein content of biomass synchronized each other. Clearly light/dark cycle
has few influence on the protein synthesis while growth stages play a more important role.
Figure 2. Growth of D. salina under continuous light (CL) and 12h/12h light/dark (LD) cycle followed by cell number and protein content. The cultivation was at temperature 20°C and light intensity ~55 µmol/m2/s with continuous mixing at 200 rpm. Figures are shown in means ± standard deviation.
CONCLUSION
Dunaliella salina proves to be a strong candidate for single cell protein production with the
highest protein content reaching 80% AFDW at the exponential phase. Despite the lower growth rate
under 12h/12h light/dark cycle, the protein content remained comparable with under continuous
light. This implies that biomass cultivation in expensive closed bioreactors with full artificial light
regime has no advantage over low-cost open outdoor cultivation under natural light regime in terms
of biomass protein content.
ACKNOWLEDGEMENTS
This research is supported by China Scholarship Council and project Microbial Nutrients on
Demand (MicroNOD).
REFERENCES
Anupama & Ravindra, P., 2000. Value-added food: Single cell protein. Biotechnology Advances, 18(6), pp.459–479. Becker, E.W., 2007. Micro-algae as a source of protein. Biotechnology Advances, 25(2), pp.207–210. Borowitzka, M.A., 1988. Algal Growth Media and Sources. In Micro-algal Biotechnology. pp. 456–465. Borowitzka L.J. and Borowitzka M.A., 1989. ß-Carotene (Provitamin A) production with algae. In Biotechnology of vitamins, pigments and
growth factors. pp. 15–26. Cuhel, R.L., Ortner, P.B. & Lean, D.R.S., 1984. Night synthesis of protein by algae. Limnology and Oceanography, 29(4), pp.731–744. Fidalgo, J.P. et al., 1998. Effects of nitrogen source and growth phase on proximate biochemical composition, lipid classes and fatty acid
profile of the marine microalga Isochrysis galbana. Aquaculture, 166(1–2), pp.105–116. Hosseini Tafreshi, A. & Shariati, M., 2009. Dunaliella biotechnology: Methods and applications. Journal of Applied Microbiology, 107(1),
pp.14–35. Markwell, M.A.K. et al., 1978. A modification of the Lowry procedure to simplify protein determination in membrane and lipoprotein
samples. Analytical Biochemistry, 87(1), pp.206–210. Nasseri, a. T. et al., 2011. Single Cell Protein: Production and Process. American Journal of Food Technology, 6, pp.103–116. Ogbonna, J.C. & Tanaka, H., 1996. Night biomass loss and changes in biochemical composition of cells during light/dark cyclic culture of
Chlorella pyrenoidosa. Journal of Fermentation and Bioengineering, 82(6), pp.558–564. Zhu, C.J., Lee, Y.K. & Chao, T.M., 1997. Effects of temperature and growth phase on lipid and biochemical composition of Isochrysis
0
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90
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102 174 246 318 390 462 582
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ein
cont
ent (
%AF
DW)
Log 1
0(X
/X0)
Hours
Protein_CL Protein_LD Cell nr_LD Cell nr_CL
9
galbana TK1. Journal of Applied Phycology, 9(5), pp.451–457.
.
10
EVOLUTION OF THE METABOLITE PROFILES OF COFFEE BEANS UNDER VARIOUS POST-HARVEST PROCESSING METHODS
Sophia Jiyuan Zhang*, Florac de Bruyn*, Vasileios Pothakos*, Julio Torrres**, Charles Lambot**, Alice Moroni**, Cyril Moccand**, Wilbert Sybesma**, Stefan Weckx* and Luc De
Vuyst*
* Vrije Universiteit Brussel, Belgium; ** Nestlé R&D Centre Tours
The journey of coffee production starts at the fresh coffee cherries. The matured coffee
cherries are harvested and undergo post-harvest processing to produce green coffee beans, which
are suitable for roasting. The processing methods, mainly wet and dry processing, are crucial for the
green coffee bean quality as well as the final coffee sensory attributes. In both cases, microorganisms
naturally present in these ecosystems and endogenous bean metabolism are active and interlinked
throughout the process. Their dynamics can be affected by the different processing methods
employed. However, little is known about the evolution of the metabolite profiles of coffee beans or
how they are impacted by different processing methods.
Aiming to follow the entire post-harvest processing chain, freshly harvested Arabica coffee
cherries were processed by four variations of wet and dry methods on an Ecuadorian farm. While
coffee samples were taken at each processing step, other parts of the cherries (e.g., mucilage from
wet-processed beans and drying outer layers from dry-processed beans) were also collected. Various
chromatographic techniques were applied to measure the targeted chemical compounds, including
UPLC-MS/MS, GC-FID, and HPAEC-PAD.
It was found that the microbial activities mainly occurred in the mucilage and drying outer
layers in the wet- and dry-processed coffee beans, respectively. The microbial metabolites were
produced and accumulated on the beans. Concurrently, the changes in the profiles of simple
carbohydrates and phenolics indicated an active endogenous bean metabolism due to abiotic
stresses. Consequently, the chemical compositions of the final green coffee beans from various
processing practices were distinct, indicating potential differences in the final coffee cup quality. To
conclude, the results of this study contributed to a better understanding of coffee bean processing,
which shed light on a potential quality enhancement of green coffee beans.
11
Lecture session 1.2
ENVIRONMENT AND AGRICULTURE
12
IS SOIL PORE STRUCTURE CONTROL ON SUBSTRATE DECOMPOSITION MANIFESTED THROUGH N AVAILABILITY?
Peter Maenhout*, Steven Sleutel,* Luc Van Hoorebeke*, Veerle Cnudde*, Jan Van den Bulcke* and Stefaan De Neve*
* Ghent University, Belgium
Soil pore structure determines the location of OM particles, the distribution of O2, water,
micro-organisms and nutrients. Mineral N availability plays a crucial role in microbial degradation of
N-poor substrates. To study these complex relationships we set up microcosm soil incubations
combined with pore network quantification. We hypothesized that C-mineralization would be
stimulated by increased N diffusion in soils with a more compact structure and higher water content.
Second, we hypothesized that fungi would dominate C-mineralization in soils with limited N
diffusion. We expect this innovative combination of methodologies to reveal new insights in the
small scale carbon dynamics.
We created soil cores with a reconstructed soil texture, namely a silt and clay (S+C) content of
50% or 20%, and a sand content of 50 and 80%, respectively. Two levels of water filled pore space
(WFPS of 25% and 50%) and amendment with OM high in nitrogen (grass) or low in nitrogen
(sawdust) were applied. During the incubations CO2 was measured frequently via GC-TCD. X-ray CT
was used to quantify the soil 3D architecture and the microbial community composition was
assessed using PLFA fingerprinting. For the first time, CT-based characteristics of the local porosity
surrounding the OM particles will be correlated with C-mineralization and microbial community
structure.
C-mineralization in the sawdust treatments was higher in the 50%_S+C soils than in the
20%_S+C soils at 25%WFPS, while such effect was not observed at 50% WFPS or for grass at both
water contents. This interactive effect of soil structure and substrate type suggests that soil structural
control on C-mineralization would be induced by differences in N diffusion. PLFA, however, did not
reveal promotion of fungal over bacterial biomarkers in treatments with likely N-limited substrate
decomposition. CT-based local porosity quantification confirms existence of localized elevated
porosity surrounding substrate particles
13
PARTITIONING SELECTION AND COMPLEMENTARITY EFFECTS TO UNDERSTAND OVERYIELDING IN TREE DIVERSITY EXPERIMENTS
Thomas Van de Peer*, Kris Verheyen**, Quentin Ponette***, Nuri Nurlaila Setiawan** and Bart Muys*
* KU Leuven, Belgium;
** Ghent University, Belgium; *** Université Catholique de Louvain, Belgium
It is generally accepted that positive effects of biodiversity on primary productivity are driven
by selection and complementarity. However, only few attempts have been made to understand these
mechanisms in forests, as trees are large and long-living, and forests therefore hard to manipulate in
comparison to e.g. grasslands or aquatic microcosms.
The present study meets these shortcomings by examining diversity-productivity relationships
(DPR) in large-scale tree-based experiments. Aboveground biomass was measured in three
plantations (GE, ZE and HE) in Belgium. These has been established in contrasting environments, but
they all have an identical design and span a diversity gradient from one to four tree species. We
applied two-way and three-way additive partitioning methodologies to measure net diversity effects
and to a posteriori distinguish between key operators.
Six years after establishment, net diversity effects were significantly positive. In the least
productive site GE, complementarity and selection were both positive and equally important.
Selection originated from competitive dominance of high-biomass species (Larix x eurolepis and
Pseudotsuga menziesii), which increased productivity at the expense of low-biomass species
(Quercus petraea and Acer pseudoplatanus). In the post-agricultural site ZE, complementarity was
positive and selection was negative. Negative selection means that low-biomass species (Fagus
sylvatica and Tilia cordata) benefited disproportionally from interspecific interactions. Their improved
performances did not fully diminish productivity of high-biomass species. Thus, part of the selection
effect was not attributable to competitive dominance but to trait-dependent complementarity.
Mixture productivity in the juvenile plantations was higher than expected from monocultures of
component species. Besides complementarity, selection is an important but complex driver of DPR,
most relevant for forest management.
14
IRON COATED SAND/GLAUCONITE FILTERS FOR PHOSPHORUS REMOVAL FROM ARTIFICIALLY DRAINED AGRICULTURAL FIELDS
Stany Vandermoere* and Stefaan De Neve*
* Ghent University, Belgium
In Flanders (Belgium) reactive phosphorus concentrations in streams and lakes are three to four
times higher than the 0.1 ppm P limit set by the Water Framework Directive. Much of the excessive P
input in surface waters is derived from agriculture and more particularly from direct P input from
artificially drained fields (short-circuiting the buffering capacity of the subsoil). Here we report on the
development and performance of filters reducing P losses via drains at lab and field scale. After a
preliminary screening experiment based on material availability, P sorption capacity and speed of P
sorption, iron coated sand and acid pre-treated glauconite were selected as starting materials for
filter development. These materials, both rich in Fe, were mixed in ratios of 100/0, 90/10, 80/20,
70/30 and 60/40 (iron coated sand/glauconite ratio, based on weight basis) and filled in plastic tubes
for saturated hydraulic conductivity (Ksat) testing. This lead to the determination of a clear
relationship between Ksat of the filter materials and filter material particle size and bulk density.
Based on this, two different filter types were developed and tested at lab scale for several days with
a 0.01 M CaCl2 solution containing 0.5 ppm P. Results showed that all types of iron coated
sand/glauconite mixtures in both filter systems reduced P outflow concentrations with 50 to almost
100%, whereby pure mixtures of iron coated sand performed the best. However only the mixtures
with 100% and 90% iron coated sand could maintain an appropriate hydraulic conductivity of 1 to 2
dm/min. Therefor only these filter mixtures were tested at field scale at two sites. During the period
of one month both filters showed a P removal efficiency of 50 to 70%, whereby the pure mixture of
iron coated sand performed the best. Moreover this pure mixture could process larger volumes than
the mixture containing glauconite.
15
TUNISIAN DAIRY FARMERS’ PERCEPTIONS OF CLIMATE CHANGE IMPACTS AND OPTIONS FOR ADAPTATION
Hajer Amamou*, Hedi Hammami*, Mokhtar Mahouachi** and Yves Beckers*
* Gembloux Agro-Bio Tech, Université de Liège; Belgium
** Ecole Supérieure d'Agriculture du Kef
Climate change strongly affects the profitability of farm animals, where a warmer thermal
environment is the major factor that can negatively affect the production efficiency in dairy cows.
Scenarios predict that climate change will increase the annual average temperature by 1.1°C by 2030
and decrease the annual precipitation in Tunisia. Due to these increasing hazards tied to climate
change, Tunisian dairy farmers are looking for effective adaptation strategies in order to secure milk
production.
This study aimed to explore the adjustments and adaptations strategies used by Tunisian
breeders in the context of climate change (CC) and the knowledge held by breeders about the effects
of CC on their dairy systems. Qualitative and quantitative variables were collected from a survey
provided to owners of 566 dairy farms among the different regions of the country. Tunisian dairy
cattle breeders used numerous strategies to limit the negative effects of CC, being classified into four
main axes: feeding strategies, management practices, environmental management and genetics. The
most frequently used strategies for adapting to CC by Tunisian dairy farmers were giving animals
access to shady areas, storage of forage, purchasing fodder, irrigating, and providing drinking water
to animals ad libitum. Almost all dairy farmers in Tunisia recognize that the major negative impacts of
CC concerned wider animal performances and its well-being and forage production.
16
EXTRACTION AND CONNECTION OF ARTIFICIAL DRAINAGE NETWORKS IN AGRICULTURAL AREAS USING LIDAR DATA
Jennifer Roelens*, Jos Van Orshoven*, Stefaan Dondeyne* and Jan Diels*
* KU Leuven, Belgium
Low-lying agricultural areas are frequently drained by ditch networks to improve production
and manage water supplies. These man-made alterations to the natural flow network impact
substantially the hydrology and water quality of the network causing them to play a key role in flood
control and surface water pollution. Localizing ditches and their connectivity to the hydrological
network helps to inform spatially-targeted water resource management decisions and future
modeling efforts.
Ditch networks can be defined from local morphologies using large area Digital Elevation
Models (DEM) with a high spatial resolution. A preliminary network is detected in an automated way
by thresholding the residual relief of the area. Noise in the preliminary network is removed by
thresholding the length of the detected segments.
Hydrological connectivity is not accounted in these methods as it does not follow a classical
flow algorithm approach. Therefore, disconnections in the preliminary ditch network are then
evaluated by a probability for connectivity. Probability maps are created using auxiliary datasets and
hydrological properties of the preliminary network.
The results are expected to facilitate input data acquirement for spatially explicit hydrological
models by avoiding field surveys that require significant human resources and funding. These results
can then improve the accuracy of spatially explicit hydrological models and the catchments
hydrologic response.
17
Lecture session 1.3
CHEMISTRY AND ENGINEERING
18
Cu-Ni PYRAZOLATE FRAMEWORKS AS HETEROGENEOUS CATALYSTS FOR THE SYNTHESIS OF NEUROACTIVE MOLECULES
Francisco García Cirujano*, Elena López Maya**, Jorge Rodriguez Navarro**, Dirk De Vos*
* Centre for Surface Chemistry and Catalysis (COK), KU Leuven, Belgium; ** Departamento de Química Inorgánica, Universidad de Granada, Spain
Tryptamine and GABA analogs are widely used for the treatment of pain, psychiatric disorders and
neurodegenerative diseases.1 In order to produce such pharmacologically active compounds in an
efficient manner, enol-type addition reactions have been applied in the presence of homogeneous
catalysts. However, due to the drawbacks of the soluble bases commercially used, we have design a
new family of solid metal-organic frameworks (MOFs) with catalytic activity in CC forming reactions.2
The NiBDP@Cu MOF used as heterogeneous catalyst is able to carry on tandem multi-steps
reactions in one-pot, obtaining the pharmaceutically active compounds in high yields after a simple
filtration of the reusable catalyst.
References:
1. Leyva-Perez et al., Angew. Chemie Int. Ed. 2014, 53 (33), 8687–8690
2. N. M. Padial et al., Angew. Chemie Int. Ed. 2013, 52 (32), 8290–8294
NiBDP@K NiBDP@Cu
K+
Cu2+
19
A STUDY OF THE ZIF-8 ZEOLITIC IMIDAZOLATE FRAMEWORK AS ADSORBENT FOR VOLATILE ORGANIC COMPOUNDS DETECTION AND REMOVAL
Thomas Virdis*
* Vrije Universiteit Brussel, Belgium
The unavoidable increase of volatile organic compounds (VOCs) in the environment has lately
attracted the attention of scientific community, as an adequate solution needs to be found to
prevent the excessive spreading of these substances in the surroundings. Among known VOCs
removal systems, gas phase adsorption provides one of the most interesting outcomes in terms of
efficiency and applicability. Physisorption of volatile compounds is a reversible spontaneous process
and allows separating target organics from the air stream. Many VOCs adsorption processes based
on activated carbons and zeolites have been reported in literature. However, the adsorption of VOC
mixtures at low concentration has been barely studied. As materials design and development has
progressed, a more recent class of adsorbents known as metal-organic frameworks (MOFs) has
emerged. MOFs consist of a crystal structure composed of organic linkers coordinated with transition
metal ions. Among the various framework types a MOF can adopt, Zeolitic Imidazolate Frameworks
(ZIFs) are surely of great interest for their topological isomorphism with zeolites. In this work, we
have investigated the adsorption of a number of representative VCs on ZIF-8. As water concentration
in the atmosphere exceeds that of the VOCs, the effect of relative humidity on VOC uptake was
studied in detail. Adsorption isotherms were measured by means of vapour phase breakthrough
experiments and gravimetric analysis at 30°C, while the single component affinity was assessed via
pulse gas chromatography (100 – 200°C). The different adsorption behaviour is analysed in terms of
the physicochemical properties of the compounds. Moreover, breakthrough profiles show
development of intermediate plateaus in specific concentration ranges, both for mixtures and pure
compounds.
20
SPATIO-TEMPORAL MODELLING OF FILTER CAKE FORMATION IN FILTRATION PROCESSES
Bram De Jaegher*,**, Wouter Naessens*,**, Jan Baetens** and Ingmar Nopens*
*BIOMATH, Department of Mathematical Modelling, Statistics and Bioinformatics, Ghent University, Belgium (email: [email protected], [email protected]).
**KERMIT, Department of Mathematical Modelling, Statistics and Bioinformatics, Ghent University, Belgium (email: [email protected]).
Abstract
The operation of membrane filtration units, used in many industrial, medical and
environmental applications, is mainly hampered by the operational cost due to membrane fouling.
Mathematical modelling can provide knowledge build-up, better process control and decision
support tools to improve the operation of these processes. However, the knowledge concerning the
underlying mechanisms of filter cake formation is still quite limited. As a result, the majority of
fouling models is still very empirical and does not provide an adequate framework for a generic
membrane fouling model. In order to further elucidate the underlying mechanisms of membrane
fouling, a mechanistic Euler-Lagrangian model was developed with a detailed description of all the
relevant subprocesses (Figure 1).
The Eulerian model layer is based on computational fluid dynamics and computes the Navier-
Stokes equations to obtain a velocity/pressure profile in the simulated domain. The movement of the
dispersed particles is modelled through the Lagrangian model layer where each particle and its
modelled quantities (velocity, forces, etc. ) are individually tracked by a moving frame of reference.
The velocity of these particles is determined by a force balance. The formation of filter cake is
modelled by means of a collision detection algorithm that tracks the collision of free moving particles
with the wall and the existing filter cake. If a collision occurs, particles can attach to the wall and the
cake layer, contributing to the growth of this layer.
Figure 1: Schematic representation of the model layers.
This modelling approach, enables the in-silico evaluation of the operational parameters (crossflow
velocity, transmembrane flux, particle size distribution, etc.) on the filter cake formation. As a
21
qualitative validation of the model, several virtual experiments were performed to replicate the
spatial segregation of particles due to the Segré-Silberberg effect. The relation between the particle
diameter and the crossflow velocity on the radial migration of dispersed particles, as described by
the Segré-Silberberg effect, was investigated. These experiments revealed an important impact of
wall repulsion effects and different lift forces on the transport of particles in tubular membranes.
Furthermore, the simulation results indicated that the membrane-directed migration of free moving
particles increased with particle size and crossflow velocity (Figure 2), which is in agreement with the
Segré-Silberberg effect.
Figure 2: Effect of the crossflow velocity on the radial migration of particles with a different entry height in a microchannel.
The presence of an equilibrium position of dispersed particles between the central axis and the
membrane in laminar flow conditions and the dubious role of the crossflow velocity raises questions
about the current turbulent operation of membrane units. The possibility to exploit this effect to
reduce membrane fouling could be very powerful and should be further investigated.
An important, but often neglected part, of mathematical modelling is the validation of the model.
One has to assess the predictive capabilities of the model by comparing the simulation results to
experimental results. To perform a controlled and reliable validation of both model layers and to
mimic the modelling assumptions as much as possible, an experimental filtration unit was designed
based on computational fluid dynamics simulations to obtain a well-characterised and laminar flow
profile in the experimental setup. This unit enables the profilometric analysis of the formed filter
cake during the experiments and the direct observation of the fouling with a high speed camera.
Bibliographic references
1. Naessens, W., Maere, T., and Nopens, I. (2012). Critical review of membrane bioreactor models – Part 1: Biokinetic and filtration models. Bioresource Technology, 122:95–106.
22
2. Owen, G., Bandi, M., and Howell, J. A. (1995). Economic assessment of membrane processes for water and waste water treatment. Journal of Membrane Science, 102:77–91.
3. Judd, S. (2008). The status of membrane bioreactor technology. Trends in Biotechnology, 26(2):109– 116.
4. Segré, G. and Silberberg, A. (1962). Behaviour of macroscopic rigid spheres in Poiseuille flow Part 1. Determination of local concentration by statistical analysis of particle passages through crossed light beams. Journal of Fluid Mechanics, 14(01):115
5. Segré, G. and Silberberg, A. (1961). Radial Particle Displacements in Poiseuille Flow of Suspensions. Nature, 189(4760):209–210.
6. Zeng, L., Balachandar, S., and Fischer, P. (2005). Wall-induced forces on a rigid sphere at finite Reynolds number. Journal of Fluid Mechanics, 536:1–25.
23
PEAK DECONVOLUTION TO CORRECTLY AND COMPLETELY ASSESS THE TRUE BAND BROADENING OF CHROMATOGRAPHIC COLUMNS
Yoachim Vanderheyden*, Ken Broeckhoven* and Gert Desmet*
* Vrije Universiteit Brussel, Belgium
The recent advances in chromatography have brought us columns that can produce such
sharp and narrow peaks that the extra-column volumes of the current generation of instruments
inevitably causes an efficiency loss. This also puts a serious strain on the ability to measure the
"column-only" efficiency of these columns, especially when using weakly retained components,
which are most sensitive to the hydrodynamic quality of the packing.
In column performance studies, the effect of extra-column band broadening (ECBB) is
traditionally eliminated using the variance subtraction method, owing its popularity to the fact that it
is based on a simple subtraction. However, by focusing only on its variance, information describing
the shape and the asymmetry of the peak is discarded. Since the variance subtraction method can
only be correctly applied when the variance is calculated via the 2nd order moment integral, the
observed “column-only” variance and its associated plate height may gravely overestimate the band
broadening compared to the parameters that are more relevant for the practical reality such as the
plate heights based on the half height width or on the 4��-, 5�- or even 6�-width.
The peak deconvolution method on the other hand can filter out the extra-column contributions
while preserving all the shape features of the peak. The present study provides evidence for the fact
that the peak deconvolution method can be applied to the current generation of high speed and high
efficiency columns and instruments and indeed allows to eliminate all ECBB while retaining all the
peak asymmetry information of the “column-only” dispersion. This has been shown by testing the
same column on 3 different systems, with different extra-column volumes and detector, and showing
that, after deconvolution, the resulting "column-only" peaks remain (slightly) asymmetric but
coincide perfectly, at least within the variability on the flow and injection reproducibility of the
instrument.
24
DESIGN AND EVALUATION OF A MINIATURIZED MICROFLUIDIC PLATFORM FOR ION-EXCHANGE CHROMATOGRAPHY
Sam Wouters* and Sebastiaan Eeltink*
* Vrije Universiteit Brussel, Belgium
Ion-exchange chromatography is the prevalent technique for the analysis of inorganic anions,
and can be used for analysis of organic acids and ionizable biomolecules. Neutralization of the ionic
mobile phase is required prior to conductivity detection. Therefore, the columns are hyphenated
with suppressors, converting the eluent to a weak acid or water, while enhancing the conductivity of
the analyte. Currently however, modular IC systems are characterized by significant extra-column
dispersion, affecting the attainable separation efficiency. This aspect can be addressed by integration
of multiple system components on a chip platform.
This contribution discusses the development of a novel chip-based platform for at-line ion-
exchange separations. The study aims at better understanding of design requirements to maximize
separation efficiency, while establishing improved detection limits when analyzing minute sample
amounts. The device encompasses three key features: separation, suppression, and detection.
Pressure resistant separation chips featuring on-chip injection have been developed. The dimensions
of the suppressor module and its operating conditions were optimized to yield a device capable of
suppressing up to 0.35 µEq/min, making the device compatible with typical gradient conditions
applied in capillary-scale separations. Detector cell geometry was systematically varied using a flow-
through ring-electrode design, resulting in a device allowing to establish limits of detection in the
sub-ppb level from common anions. A fivefold increase in signal-to-noise ratio was achieved
compared to a commercial capillary conductivity detector. The current contribution also
demonstrates the integration of conductivity detection on a microfluidic membrane suppressor. The
device was used to analyze minute samples taken from an ice core drilled in Antarctica, allowing to
detect traces of volcanic and biological activity.
25
Lecture session 2.1
FOOD TECHNOLOGY AND INDUSTRIAL MICROBIOLOGY
26
VISCOELASTIC PROPERTIES OF HIGH PRESSURE HOMOGENISED CITRUS FIBRE FRACTIONS OBTAINED AFTER SEQUENTIAL PECTIN EXTRACTION
Katleen Willemsen*, Agnese Panozzo* and Marc Hendrickx*
* KU Leuven, Belgium
The primary cell wall (CW) of fruit and vegetables is constituted of a load-bearing network of
cellulose and hemicellulose, embedded in a pectin matrix. The latter is believed to act as a glue
holding the CW fibres together. As a consequence, fruit and vegetables CW fibres are organised in a
tightly dense network, that impairs their structuring potential upon dispersion. In this regard, the
present study aimed at understanding the effect of pectin removal and high pressure
homogenisation on the microstructure and viscoelastic properties of citrus fibres. Selective
solubilisation and removal of pectin from citrus peels was achieved by sequential pectin extraction.
Thereafter, the obtained fibre insoluble residues and filtrates were characterised for their pectin
composition (neutral sugar and galacturonic acid content, degree of methoxylation, and molar mass
distribution). Moreover, microstructure, particle size distribution, and viscoelastic characteristics of
the diverse insoluble residue suspensions were investigated by microscopy, laser diffraction, and
rheological analyses.
Due to different extraction conditions, the CW insoluble residues and filtrates showed various
pectin composition, in terms of both amount as type of pectin. In particular, highly methoxylated
branched pectin was removed under mild water conditions, low methoxylated linear pectin using a
chelator while cellulose bound pectin was solubilised under alkaline conditions. According to the
present results, the extent rather than the type of pectin removal seemed crucial to obtain
viscoelastic enhancement of the residual citrus fibre suspensions. Increase in intermicrofibrillar void
volume, created between the cellulose-hemicellulose network by extensive pectin extraction,
resulted in increased particle size and viscoelastic properties upon high pressure homogenisation.
Contrarily, homogenisation of non-depleted CW material resulted in the disruption of the stiff
microfibrillar CW structure.
27
ROLE OF DEGREE AND PATTERN OF METHYLESTERIFICATION ON Fe2+ ADSORPTION CAPACITY OF CITRUS PECTIN
Miete Celus*, Katrien Roggen*, Zahra Jamsazzadeh Kermani*, Clare Kyomugasho*, Tara Grauwet*, Ann Van Loey* and Marc Hendrickx*
*KU Leuven, Belgium;
Pectin, a cell wall polysaccharide present in fruits and vegetables possesses several
functionalities in both food and non-food related industries, with its polyvalent ion binding capacity
being of particular interest. This pectin property is greatly attributed to its degree of
methylesterification (DM) and blockiness (DBabs), which are a measure for the percentage and
distribution of non-methylesterified galacturonic acid units, respectively. Although pectin is
hypothesised to bind several cations including Fe2+, only its Ca2+ binding capacity has been greatly
explored in the food industry. This study is therefore aimed at investigating the role of pectin
structural properties (DM and DBabs) on its ability to bind Fe2+. The obtained insights could
contribute in this way to clean label products, where use of pectin as a natural food ingredient
compared to synthetic ingredients in Fe2+ chelating applications is more appealing to consumers.
Pectins with different DMs and DBabs were tailored by controlled demethylesterification of
high DM citrus pectin. This was achieved using carrot pectin methylesterase or saponification with
NaOH resulting in pectin with a blockwise (high DBabs) or random (low DBabs) distribution of
methylesters, respectively. Subsequently, Fe2+ adsorption isotherms of the derived pectins were
obtained through equilibrium dialysis studies and the experimental data were fitted according to the
Langmuir adsorption isotherm model in order to quantify the maximum adsorption capacities.
Results of this study showed that both DM and DBabs influence the Fe2+ binding capacity of
pectin. The lower the DM or higher the DBabs of pectin, the greater its Fe2+ binding capacity.
However, the DBabs of pectin showed a higher impact on the maximum Fe2+ adsorption capacity
compared to DM. Consequently, targeted modification of pectin structural properties is useful in
optimising its chelating capacity and therefore the associated functional properties.
28
EXPLORING THE MICROBIOTA ASSOCIATED WITH GREEN COFFEE BEAN PRODUCTION
Florac De Bruyn*, Sophia Zhang*, Vasileios Pothakos*, Charles Lambot**, Julio Torres**, Alice Moroni**, Cyril Moccand**, Wilbert Sybesma**, Stefan Weckx* and Luc De Vuyst*
* Vrije Universiteit Brussel, Belgium;
** Nestlé R&D Centre Tours
Coffee is the most consumed beverage in the world. It is brewed from the roasted and ground
seeds of the coffee tree. However, there is a long way to go from the harvesting of fresh coffee to the
brewing of a cup of coffee. Indeed, harvested coffee needs to undergo processing before it can be
roasted. This on-farm post-harvest processing will yield green coffee beans, which is the raw material
for roasting. In essence, it is a fermentation that is performed by a complex microbial community.
However, this community can affect coffee quality in beneficial or detrimental ways. Little is known
about the ecology of the microbiota associated with coffee processing. Moreover, a vast array of
different processing methods exists globally and each one has its own specificities. Therefore, this
study aimed at elucidating differences in the community composition associated with coffee
different processing methods. Two wet and two dry processing experiments were set up in parallel
on an Ecuadorian farm. This allowed to assess how the communities were shaped not only by the
processing method, but also by technological practices employed locally. Lactic acid bacteria (mainly
leuconostocs) and Pichia yeasts were present in all experiments, regardless of processing type or
technological practices. Some microbial groups were influenced by the type of processing, for
instance, acetic acid bacteria and non-Pichia yeasts were more prevalent in dry processing. Others
were impacted by the practice employed, as showed by shifts towards acid-tolerant lactobacilli with
increasing fermentation time. This study contributes to the characterization of the microbiota
associated with different types of post-harvest coffee processing. Assessing who is there is the first
step to knowing what they are capable of. Ultimately, the answers to these questions will help
improve coffee quality and make its production more sustainable for all stakeholders of the coffee
value chain.
29
INFLUENCE OF OIL TYPE ON IN VITRO LIPID DIGESTION AND CAROTENOID BIOACCESSIBILITY: A KINETIC STUDY
Sarah Verkempinck*, Laura Salvia Trujillo*, Lucie Moens*, Marc Hendrickx* and Tara
Grauwet*
*KU Leuven, Belgium
Carotenoid absorption is linked to lipid digestion due to the hydrophobic nature of these
micronutrients. In order to exhibit biological activity, carotenoids must be successively released from
the food matrix, transferred into a lipid phase, incorporated into mixed micelles and absorbed into
the intestinal mucosa. Lipid digestibility and subsequent carotenoid bioaccessibility, which is the
micellarized fraction, may be determined by the oil type used in emulsion formulation. Therefore, we
investigated the specific influence of oils unsaturation degree in emulsions on both lipid digestion
and carotenoid bioaccessibility through a kinetic study. Emulsions were prepared with different
carrot enriched oils (5% w/v), being olive; soybean and linseed oils and were stabilized with sucrose
ester (0.5% w/v). All emulsions were subjected to in vitro digestion consisting of a gastric and small
intestinal phase. Clear emulsion destabilization was observed during the gastric phase with visible
flocculation and coalescence with regions of free and emulsified oil, as shown by particle size values
and microstructure. Consequently, incomplete lipid digestion occurred in the intestinal phase for all
emulsion regardless the oil type. Despite this incomplete digestion, differences in terms of
carotenoid incorporation into micelles were still observed between all oil types. Olive oil emulsions
led to faster carotenoid micellarization and a higher final carotenoid bioaccessibility compared to
soybean and linseed oil emulsions. This suggests that monounsaturated fatty acids from olive oil,
which might be slightly more hydrophobic in comparison to polyunsaturated fatty acids from
soybean or linseed oil, may lead to the formation of mixed micelles with greater capacity of
solubilizing hydrophobic compounds, like carotenoids. The results observed in this work evidence the
relevance of the lipid composition in achieving optimal carotenoid bioaccessibility in the
gastrointestinal tract.
30
THE INFLUENCE OF CITRATE IN TYPE II SOURDOUGH FERMENTATIONS INITIATED WITH A CITRATE-POSITIVE LACTIC ACID BACTERIAL STARTER CULTURE
Andrea Comasio*, Henning Harth*, Simon Van Kerrebroeck* and Luc De Vuyst*
* Vrije Universiteit Brussel; Belgium
Currently, certain strains of lactic acid bacteria and yeasts are applied as starter cultures for
the industrial production of sourdoughs, which are mainly used as flavour ingredients in (industrial)
bakeries. The starter cultures are responsible for acidification (lactic acid bacteria), aroma generation
(lactic acid bacteria and yeasts) and leavening (yeasts and heterofermentative lactic acid bacteria),
which are desirable properties for sourdough products. Unfortunately, the aroma and taste profiles
of the manufactured bakery products do not always completely fulfil the expectations of the
consumers and producers and, hence, both parties are continuously searching for innovative
products with unique aroma and taste profiles. This can be achieved through the addition of extra
ingredients such as yoghurt, fruits, and seeds. This study aimed at examining the influence of added
citrate on the competitiveness of a citrate-consuming lactic acid bacterial starter culture strain,
namely Lactobacillus crustorum LMG 23699, used to initiate a wheat sourdough fermentation
process, on its metabolite production kinetics, and on the organoleptic properties of the resulting
sourdoughs and baked products. Whereas there were no differences in counts between
fermentations performed with or without citrate, the data indicated that sourdough fermentations
carried out with the addition of citrate increased the production of lactic acid. Also, the sourdoughs
obtained with the use of citrate produced acetoin. This typical and desired compound (butter aroma)
gave a more complex aroma to the baked products. In conclusion, citrate can be an interesting
sourdough ingredient to accentuate the aroma of baked products.
31
TOWARDS UPGRADING OF WASTEWATER RESOURCES TO MICROBIAL PROTEIN: VOLATILE FATTY ACIDS IMPACTING GROWTH KINETICS AND YIELD OF PURPLE BACTERIA
Abbas Alloul* and Siegfried Vlaeminck*
* Antwerp University; Belgium
The conventional fertilizer–food chain is a cascade of inefficiencies. Upgrading nutrients from
wastewater to microbial biomass could improve the efficiency, with this protein-rich product used as
feed. It is a challenge to a produce a controllable biomass on wastewater, given its complexity in
organics composition. Fermentation might render a solution, through its generation of simple
Volatile Fatty Acids (VFA). Purple-non sulfur bacteria (PNSB) cultivated in a photoheterotrophic mode
provide an excellent target group, as they have a perfect carbon assimilation efficiency and a high
growth rate compared to other phototrophs. The objective of this study was to map the effects of
VFA on PNSB growth kinetics, carbon yield and protein production.
Batch cultivations were performed with three different VFAs (acetate, propionate, butyrate)
and with a mix of these compounds (1/1/1 on C-basis). The microorganisms used for the
experiments were Rhodopseudomonas palustris, Rhodospirillum rubrum and Rhodobacter
sphaeroides along with a synthetic community (mixture of the three strains) and a PNSB enriched
community. All tests were performed under photo-anaerobic (30W/m²) conditions at 28°C.
Results showed that the growth rate of the pure cultures and the enriched community was
elevated between 1.3-2.5 times for the VFA mix compared to the single VFA. The carbon yield for all
experiments was around 1 gCOD-biomass/gCOD-fed and there was no difference between different
PNSB and the source of organic. Overall, the enriched community performed best, with superior
growth rates (1.8–2.2/d) and protein productivity (1.3 kg dry weight/m3/d).
This study demonstrated that the VFA-profile resulting from fermentation from wastewater
will strongly effect the PNSB production and product characteristics. Best results were obtained with
a VFA mix and with an enrichment community, conditions that prevail in wastewater applications,
strengthening the potential for PNSB production on fermentate.
32
Lecture session 2.2
ENVIRONMENT AND AGRICULTURE
33
FLEMISH POLICY TACKLING AGRICULTURAL AMMONIA EMISSIONS: STILL ROOM FOR IMPROVEMENT
David De Pue * and Jeroen Buysse*
* University of Gent; Belgium
Ammonia (NH3) emissions from livestock farms cause eutrophication in nearby nature
reserves. This process of atmospheric deposition threatens the biodiversity and conservation goals in
protected nature areas. In Flanders, the control of this problem is mediated through the licencing
policy. For each new environmental permit application involving ammonia emissions, a Significance
Score is calculated. This score is a measure of the impact on the location where the damage caused
by the new project is presumed to be the highest. Projects were the Significance Score exceeds a
certain limit cannot get a permit, while projects with a moderately high Significance Score can only
get a permit if they can guarantee that there is no increase in the emission when compared to the
previous situation. Projects with a low Significance Score are exempt from additional emission
restrictions. To evaluate the efficiency and effectiveness of this policy, we designed a linear
programming (LP) model, applied to a dataset consisting of all industrial pig- and poultry farms in
Flanders. For all these farms, we calculated the Significance Score and the Total Impact Score, an
alternative that is a better reflection of the total damage caused by the emission. The LP model
maximizes the societal profit, which is the sum of the individual farms minus the external health cost
related to the formation of secondary particulate matter. The farms all have an individual permit
constraint, while in the reference scenario, they also have an individual constraint related to their
significance score. If we rephrase the model, so that it minimizes the total impact while imposing the
constraint that the societal benefit should be at least as big as for the reference scenario, the total
impact is 23.7% less than in the reference scenario. This indicates that there is still room for
improvement in terms of environmental effectiveness of the policy, without reducing the total
societal benefit.
34
DOES REPLACING GRASS SILAGE BY MAIZE SILAGE IN FLEMISH DAIRY CATTLE DIETS LEAD TO METHANE REDUCTION?
Dorien Van Wesemael*, Leen Vandaele*, Nico Peiren*, Veerle Fievez** and Sam De
Campeneere*
* ILVO (Instituut voor Landbouw- en Visserijonderzoek); Belgium ** Laboratory for Animal Nutrition and Animal Production Quality, Ghent University
It is often stated that replacing grass silage (GS) by maize silage (MS) in dairy rations is a
promising nutritional strategy to reduce methane (CH4) emissions (Van Middelaer et al., 2013; Mills
et al., 2001), as MS is rich in starch. In practice, however it is not feasible to simply replace one
forage by another without affecting the performance of cows (i.e. the milk production and/or
composition). In order to have a sufficiently high starch supply in the total diet (±20%, Grant, 2010),
diets rich in GS are accompanied by high starch concentrates (HSC). In this trial we compared a
GS/MS diet (65/35 ratio on DM (dry matter) base) with a MS/GS diet (65/35 ratio), to investigate the
effect on CH4 emissions. We used 12 high-producing (31±3 kg milk/day) Holstein Friesian cows,
divided in two uniform groups (control and treatment). At the end of a control period of six weeks, in
which all cows received the GS/MS diet with HSC, the CH4 emissions of all cows were measured in
open-circuit chambers (OCC). After these measurements, the treatment group switched to the
MS/GS diet for a six week period. The control group remained on the GS/MS diet with HSC for that
period. In the last week CH4 emissions of all cows were measured again in the OCC. Replacing GS by
MS did not change the absolute CH4 emissions of the cows (on average 423 and 425 g CH4/day
respectively), nor the CH4 emissions expressed per kg DM intake (DMI) or per kg of produced milk
(MP) (20g CH4/kg DMI, 16g CH4/kg MP, respectively). Based on these results we can conclude that in
practice the replacement of GS by MS in typical Flemish dairy diets does not lead to CH4 reduction,
because it is more than only the exchange of two forages.
35
ECOLOGICAL WATER QUALITY AND THRESHOLD RESPONSES OF MACROINVERTEBRATE COMMUNITIES TO STREAM VELOCITY IN THE GUAYAS RIVER BASIN (ECUADOR)
Thi Hanh Tien Nguyen*, Pieter Boets**, Koen Lock*, Minar Naomi Damanik Ambarita*, Marie Anne Eurie Forio*, Peace Liz Sasha Musonge*, Natalija Suhareva*, Elina Bennetsen*,
Gert Everaert*, Luis Elvin Dominguez Granda***, Thu Huong Thi Hoang**** and Peter Goethals*
* Ghent University, Laboratory of Environmental Toxicology and Aquatic Ecology, Belgium;
** Provincial Centre of Environmental Research, Ghent Belgium *** Escuela Superior Politécnica del Litoral, Ecuador
**** Hanoi University of Science and Technology, Vietnam
The Guayas River basin is one of the most important water resources in Ecuador, but the
expansion of human activities has led to a degraded water quality. Unfortunately, detailed
information on the water quality and the ecological status of the Guayas River basin is not available
for decision making and water management. The purposes of this study were: (1) to explore the
ecological water quality and the importance of physical-chemical variables in structuring the
macroinvertebrate communities and (2) to determine if the thresholds in stream velocity related to
macroinvertebrate community composition could be identified in the Guayas River basin.
Macroinvertebrates and physical-chemical water quality variables were sampled at 120 locations
during the dry season of 2013 in the Guayas River basin. The Biological Monitoring Working Party –
Colombia (BMWP-Colombia) values were calculated to assess the ecological water quality. Canonical
Correspondence Analysis (CCA) was performed to identify relevant physical-chemical characteristics
of the river influencing the distribution of the macroinvertebrate communities. The BMWP-Colombia
scores indicated that water quality of the sampling sites within the Guayas River basin ranged from
good to very bad. According to the CCA, the most important environmental factors influencing the
distribution of macroinvertebrate communities are stream velocity, chlorophyll, conductivity,
temperature and elevation. Threshold Indicator Taxa ANalysis (TITAN) was able to discriminate
between the macroinvertebrate communities related to stagnant water (Daule-Peripa reservoir) and
the macroinvertebrate community related to running waters. The results provide essential
information to further support water management plans of the Guayas River basin. Information
obtained will be useful for management of similar rivers in South-America, as well as the rest of the
world.
36
DEVELOPMENT AND VALIDATION OF AN UHPLC-ESI-MS/MS METHOD TO QUANTIFY ESTROGENIC COMPOUNDS AS PYRIDINE-3-SULFONYL DERIVATIVES IN AQUEOUS
MATRICES
Alex Glineur*, Sébastien Ronkart**, Katherine Nott**, Georges Lognay* and Eva Tyteca*
* Gembloux Agro-Bio Tech, Université de Liège; Belgium ** Société Wallonne des eaux
Natural estrogens (estrone:E1, 17-β-estradiol : E2, estriol : E3) and synthetic estrogen (17-α-
ethinylestradiol: EE2) are powerful endocrine disruptors. They may have deleterious effects on
aquatic wildlife and also humans even at extremely low concentrations. For this reason, these
molecules have been included in a watch list from the European Commission regarding emerging
aquatic pollutants. The maximum detection limits are set at 0.035 and 0.4 ng/L for EE2 and E1, E2
respectively. Reaching such low levels of concentration of estrogenic compounds is a challenge, even
using state-of-the-art analytical methods. In this study, we developed a UHPLC-ESI-MS/MS (ultra-high
performance liquid chromatography-electrospray ionization-tandem mass spectrometry) method
allowing the quantification of E1, E2, E3 and EE2 residues in aqueous matrices. Studies commonly
used ESI in negative mode, albeit the poor ionization efficiency of native estrogenic compounds in
this mode. In this study, the molecules were derivatized using a sulfonyl chloride reagent: pyridine-3-
sulfonyl (P-3-S). The resulting response in the positive mode was significantly enhanced. Similarly to
other dansyl derivatives, the product ion spectra of the P-3-S derivatives indicate ions originating
from the derivatization reagent moiety (Zhang et al. 2004). Moreover, several other ions were
included in the product ion spectra of the P-3-S. Their specificity was assessed by a qualitative
approach implying the analysis of different types of water samples (groundwater, surface water).
Some product ions were found to be noticeably better for quantification and confirmation of the
analytes. The developed analytical method was validated according to the NF T90-210 norm which is
suitable to assess the performances of a method in the water quality field. The limits of detection
were 0.012, 0.015, 0.030 and 0.006 ng/L in groundwater and 0.267, 0.237, 1.33 and 0.087 ng/L in
surface water for E1, E2, E3 and EE2 respectively.
37
EMERGING THREATS TO UGANDAN HONEYBEES, PILOT STUDY REVEALS PRESENCE OF PESTICIDES AND HONEYBEE PATHOGENS
Deborah Ruth Amulen*, Paul Cross**, Lina De Smet*, Niels Piot*, Marijke D’haese*, Dirk C.
de Graaf*, Pieter Spanoghe* and Guy Smagghe*
* Ghent University; Belgium ** Bangor University, United Kingdom
Demand for honey in the global market outstrips supply. In an effort to avert this, many
development organizations and governments are encouraging African farmers to embrace
beekeeping, a process that requires healthy honeybees and safe products. However, information on
the health status of these honeybees especially in Uganda is generally limited, including knowledge
of hive product contamination. Our study set out to address the above knowledge gaps through
molecular pathogen and multi-residue screening of agricultural pesticides commonly used. A total of
286 honeybee colonies from 143 apiaries across three ecological zones and 93 hive products (honey,
honeybees, and beeswax) were collected for analysis. Out of the 10 virus pathogens screened, four
were detected i.e. Deformed wing virus, Black Queen Cell Virus, Acute Bee Paralysis and Sac Brood
virus. Other pathogens present and some of which were first time detection in Ugandan colonies
included Phorid fly, Spiroplasma spp, Trypanasomatid spp and Apicytis bombi. Additionally, out of 36
compounds screened we detected 20 pesticides in beeswax with higher frequencies near citrus and
tobacco farms linking contamination to agricultural activity. Although, presence of pesticides and
honeybees are known to cause devastating effects to bees, at the moment the detected
concentrations in Ugandan colonies may not be much of risk, since all levels were below the lethal
dose for honeybees and maximum residue limits for EU. We still recommend routine monitoring to
ensure the potential pathogen and pesticide effects to honeybees are regulated.
38
CONTRASTING VULNERABILITY AND RESILIENCE TO DROUGHT-INDUCED DEFOLIATION IN MIXED VERSUS PURE STANDS.
Ana Rita Silva*, Koenraad Van Meerbeeck*, Thomas Van de Peer*, Geert Sioen**, Christian
Laurent***, Quentin Ponette****, Kris Verheyen* and Bart Muys*
* Ghent University, Belgium; ** Research Institute for Nature and Forest (INBO), Belgium *** Département de la Nature et des Forêts (SPW), Belgium;
**** Université catholique de Louvain, Belgium
Drought is one of the most important climate-related events through which rapid ecosystem
changes can occur as it affects the survival and function of existing forests. The impacts of these
changes become evident during regular monitoring efforts of tree health, such as those commonly
undertaken in the ICP Forests monitoring plots.
In this study, we revisited the trends in defoliation of Belgian monitoring plots, and
hypothesized that the effects of climate-related vitality loss are tempered in mixed stands in
comparison to monocultures. Three main European species were considered: European beech,
sessile oak and pedunculate oak, growing in pure and mixed stands, which allowed us to test for
species identity and diversity effects in terms of forest defoliation response to drought, from 1988 to
2015. Within the covered period, the most extreme drought episodes were always followed by
defoliation peaks. Our results also indicate that sessile oak is more tolerant to drought than beech;
but mixed beech has the quickest recovery and was significantly more resilient than in pure stands.
Finally, the higher resistance and resilience to episodic drought stress of sessile oak, both in
pure and mixed stands, provide additional arguments for a preferential choice of this species as a
climate change adaptation strategy.
39
Lecture session 2.3
HUMAN HEALTH AND GENOMICS AND BIOTECHNOLOGY
40
FUNCTIONAL AND STRUCTURAL ELUCIDATION OF A SSDNA-BINDING PROTEIN ENCODED BY THE N4-LIKE, PSEUDOMONAS PHAGE LUZ7
Maarten Boon*, Jeroen De Smet*, Elke De Zitter*, Marc De Maeyer*, Luc Van Meervelt*
and Rob Lavigne*
* KU Leuven, Belgium
Bacteriophages are the natural enemy of bacteria, which makes them ideal for investigating
potential antibacterial applications. Through millions of years of coevolution they have become
excellent at setting crucial host processes to their hand. A significant amount of this host
reorganization is directed through protein-protein interactions of phage ‘early’ proteins with host
target proteins [1]. Hence, they could provide new insights on possible antibacterial targets.
However, the function of these phage proteins is largely unknown. Moreover, most of them have
little to no sequence homology with known proteins, making functional predictions difficult.
The early phage protein studied here is gp14 from a Pseudomonas aeruginosa phage, LUZ7.
This protein was previously shown to be toxic when expressed in P. aeruginosa, leading to
filamentous growth of the cell [2]. Based on in silico predictions, we tested this protein for DNA
binding activity in various Electrophoretic Mobility Shift Assays (EMSAs). The results show sequence
independent binding to both dsDNA and ssDNA and RNA, with a much higher affinity for ssDNA.
Using X-ray data, a model of gp14 was built. The model reveals that the protein occurs as a
homodimer with features of a PC4-fold. This is a fold commonly found in ssDNA binding proteins and
supports the ssDNA binding character of the protein.
Comparison of Pseudomonas phage LUZ7 to the related coliphage N4 indicates that this ssDNA
binding phage protein might be a functional analogue of N4 gp2, a protein recently elucidated in E.
coli. Interestingly, both proteins have no sequence similarity whatsoever, but their biological role in
shifting transcription from early to middle phase might be conserved.
REFERENCES
[1] Roucourt, B., Lavigne, R. (2009). Environ Microbiol 11: 2789-2805
[2] Wagemans, J., et al. (2014). Cellular Micrbiol. 16: 1822-1835
41
INTRINSICALLY DISORDERED PROTEINS – EXTRAORDINARY PROTEIN FUNCTIONS AND NOVEL METHOD FOR THEIR DETECTION
Nevena Hristozova*, Denes Kovacs* and Peter Tompa*
* VUB – VIB, Belgium
The importance of protein multi-functionality remains underestimated. We know very little of
the ability of certain proteins to perform conceptually different functions with the same ultimate
goal of protecting the cell they are active in. Plants accumulate Late Embryogenesis Proteins to a
large extent under abiotic stress conditions alongside other protective molecules. We are able to
show now that some of these LEA proteins can function as promiscuous chaperones, while others
showed them being able to bind ions, water or membranes. The lack of conventional chaperone
structural domains in LEA proteins might be the evolutionary tradeoff of specificity and binding
strength for the ability to protect various partners directly via transient weak interactions, and
indirectly by sequestering ions and/or binding water. Investigating the ability of some proteins to
double as chaperones during adverse conditions would provide insights into the ability of organisms
to repurpose already synthesized proteins in conditions when producing new, more specific/suitable
proteins might not be an option. In a rapidly changing environment, every bit of knowledge of the
mechanisms plants employ to survive stress is of unprecedented importance for our efforts to
develop sustainable and resilient crop varieties, in order to ensure food security.
We developed a method we to test putative chaperones which we believe is a significant
improvement of the state of the art. The use of it may lead to a considerable increase in the number
of experimentally verified proteins with such functions, and may also allow the dissection of their
molecular mechanism. Additionally, we test the fitness of our method to assess the proteostatic
functions of complex protein mixtures. In our case we tested a full bacterial protein extract, but we
believe it being adaptable for measuring blood serum or cerebral fluids, where increase of
chaperones often indicates inflammation or disease.
42
HokB, A PORE-FORMING TOXIN, INDUCES PERSISTENCE AFTER DIMERIZATION
Dorien Wilmaerts*, Jan Michiels* and Natalie Verstraeten*
* KU Leuven, Belgium
Infectious diseases are among the leading causes of death worldwide. In addition to the well-
known and widely studied problem of resistance, bacterial populations are known to harbor a small
number of so-called persister cells that transiently show tolerance to very high doses of antibiotics.
Among the known effectors of persisters are toxin-antitoxin modules that can induce dormancy or
growth arrest when the toxin concentration reaches a certain threshold. Recently, we showed that
the conserved GTPase Obg mediates bacterial persistence by upregulating expression of the toxin
hokB. This gene encodes a membrane protein which after insertion causes the membrane potential
to collapse, thereby inducing persistence. In the current project we further elucidated the mode of
action of HokB. We discovered that formation of disulfide bridges in the periplasmic part of the
peptide is crucial for induction of persistence. The formation of these dimers is effectuated by an
oxidoreductase in the periplasm. Interestingly, a specific balance between monomers and dimers of
HokB seems to be important for the induction of persistence. The biological consequences of this
dimerization are currently under investigation as we hypothesize that the monomer/dimer ratio has
an influence not only on the induction of persistence but also on the resuscitation of HokB-induced
persister cells. Furthermore, in vitro experiments showed that HokB is a pore-forming toxin, and that
the pore size is too big to be selective. Identifying the nature of molecules that are transported
through HokB pores is the subject of ongoing investigation. Combined, our findings provide new
insights in the regulation of persistence at the single-cell level and we anticipate that these results
will contribute to a better understanding of the molecular mechanisms underlying persistence.
43
NANOBODY-BASED DEPLETION OF PROTUMORAL TUMOR-ASSOCIATED MACROPHAGES AS NOVEL CANCER THERAPY
Evangelia Bolli*, Matthias D'Huyvetter**, Kiavash Movahedi*, Nick Devoogdt**, Tony
Lahoutte** and Jo Ginderachter*
* CMIM, Vrije Universiteit Brussel, Belgium ** ICMI, Vrije Universiteit Brussel, Belgium
Tumors are considered as organoid structures, which contain not only cancer cells but also
non-transformed types of cells, the stromal cells. A bidirectional interplay exists between
transformed and non-transformed cells, which results in tumor progression and metastasis. Tumor-
associated macrophages (TAMs) are one of the dominant cell types present in murine and human
tumors. Clinical and experimental studies have delineated the highly pro-tumorigenic role of TAMs
through a variety of mechanisms. For this reason, the depletion of pro-tumorigenic TAMs forms an
attractive perspective in the treatment of cancer.
We have previously shown that the Macrophage Mannose Receptor (MMR, CD206) is highly
expressed on the surface of pro-tumorigenic TAMs, rendering it an important molecule for targeted
TAM depletion. Hence, we intend to deplete the pro-tumorigenic MMRhigh TAMs by using anti-MMR
Nanobody (Nb)-conjugates, whereby Nbs are the antigen-recognition domains of camelid heavy
chain-only antibodies. For this purpose, we have generated both anti-mouse and cross-reactive anti-
human/mouse MMR Nbs and have selected the lead compounds, cross-reactive Nb3.49 and anti-
mouse Nb1, based on their optimal in vivo pharmacokinetic properties. [99mTc]-labeled Nb1 exhibits
high tumor penetrance, upon blocking of extra-tumoral binding sites with an excess of unlabeled
bivalent Nb1, as visualized via SPECT/microCT imaging. The same behavior has been observed in the
case of [18F]-labeled Nb3.49 via PET imaging. We have currently conjugated the lead anti-MMR Nb1
to the therapeutic radionuclide 177Lu for radioimmunotherapy. Co-administration of the therapeutic
radiolabeled MMRNb1 with an excess of unlabeled bivalent MMRNb1 to TS/A breast tumor-bearing
mice, leaded to remarkable retardation of tumor growth compared to non-treated animals.
44
AKKERMANSIA MUCINIPHILA COLONIZATION OF AN IN VITRO DISTAL COLON IS LARGELY MUCIN AND Ph DEPENDENT
Florence Van Herreweghen*, Pieter Van den Abbeele**, Thijs De Mulder***, Rosemarie De
Weirdt*, Annelies Geirnaert*, Emma Hernandez Sanabria*, Ramiro Vilchez-Vargas*, Ruy Jauregui****, Dietmar Pieper****, Willem De Vos*****, Clara Belzer***** and Tom Van de
Wiele*
* Ghent University, Belgium ** ProDigest, Belgium
*** ILVO, Belgium *** Helmholtz Centre for Infection Research, Germany
***** Wageningen University, The Nederlands
Introduction and objectives: Akkermansia muciniphila is an abundant human colon microbe
that feeds on mucin as its sole carbon, nitrogen and energy source, thereby producing acetate and
propionate. A. muciniphila has been correlated with human health in various studies but a
mechanistic understanding of its colonization is still lacking. Materials and methods: In this study, we
used the dynamic SHIME model to uncover the ecological behavior of A. muciniphila in the colon, i.e.
its main site of colonization and its response to environmental parameters that are associated with a
healthy gut such as a low colon pH, the consumption of fibres (inulin) and mucin. Results and
discussion: A. muciniphila was found to colonize the distal colon (pH 6.6-6.9) more abundantly (+4
log copies/mL) than the proximal colon (pH 5.6-5.9) and this colonization pattern is due to the
preference of A. muciniphila for pH 6.15-6.9. The addition of mucin upon ten days of mucin
deprivation caused a dramatic increase of A. muciniphila (±4,5 log increase over two days), far
exceeding the response of any other bacteria present. The inulin treatment did not affect A.
muciniphila in this in vitro model, despite the observed effect of inulin on A. muciniphila in vivo (Van
den Abbeele et al., 2011). Together, our findings indicated the preference of A. muciniphila for the
distal colon environment due to its preference for more neutral pH and uncovered the quick and
stable response of A. muciniphila to mucin supplementation. The results of this study are indicative
of a high sensitivity of A. muciniphila to environmental changes. This high sensitivity could explain
why its abundance in vivo changes drastically when the conditions in the colon change, for example
due to certain disease states (Everard et al., 2011; Png et al., 2010; Wang et al., 2011; Zhang et al.,
2009). This could clarify why A. muciniphila is so often correlated with diseases and might be an
indicator species for gut health.
45
REVEALING THE ROLE OF TBC1D24 MUTATIONS IN EPILEPSY
Jone Paesmans*$, Baptiste Fischer*$, Kevin Lüthy**$, Jone Paesmans*, Charlotte De Koninck*, Ine Maes**, Jef Swerts**, Sabine Kuenen**, Valerie Uytterhoeven**, Wim
Versées*, Patrik Verstreken**
* Vrije Universiteit Brussel, Belgium ** KU Leuven
$ Equal contribution
Epilepsy can be defined as a group of neurological diseases, which are characterized by
recurrent and unprovoked seizures. Genetic forms of epilepsy have been mainly ascribed to
mutations in genes encoding ion channels and neurotransmitter receptors. However, nowadays also
mutations encoding proteins involved in other pathways are being identified as genetic causes of
epilepsy. One of these newly discovered epilepsy genes is TBC1D24 coding for the TBC1D24 protein.
Several studies have linked mutations in this gene to different devastating forms of epilepsy and also
to other neurological diseases such as DOORS syndrome and non-syndromic hearing loss. However,
the molecular mechanisms underlying these pathologies are still unresolved.
Via a genetic screen for alterations in synaptic transmission, an ortholog of TBC1D24 was
identified in Drosophila, called Skywalker. We were able to solve the crystal structure of one of the
domains of Skywalker, namely the TBC domain, revealing an unexpected cationic pocket conserved
among TBC1D24 homologs. Cocrystallization and biochemistry showed that this pocket binds
phosphoinositides phosphorylated at the 4 and 5 position. This binding is disrupted by some patient
mutations present in this pocket. Further, we showed that membrane binding via this pocket restricts
Skywalker diffusion in presynaptic terminals. In addition, the pathogenic mutations cause severe
neurological defects in flies such as impaired synaptic-vesicle trafficking and seizures. These defects
are reversed by genetically increasing synaptic PI(4,5)P2 concentrations through Synaptojanin
mutations.
Hence, we discovered that a TBC domain affected by clinical mutations directly binds
phosphoinositides through a cationic pocket and that phosphoinositides binding is critical for
presynaptic function.
46
POSTER SESSIONS
47
Poster session A: Food technology and Industrial Microbiology (noon session) A.1 Integrating clean label ingredients and non-thermal processing to retain fresh quality of cloudy fruit
juice during refrigerated storage. Junjie Yi, Biniam Kebede, Kristiani Kristiani, Tara Grauwet, Ann Van Loey and Marc Hendrickx A.2 The effect of heat shock on browning-related enzyme activity in lettuce. Celine Vanden Abeele, Katleen Raes and Imca Sampers A.3 Dissection of novel resistance mechanisms in Cupriavidus metallidurans. Md Muntasir Ali, Kristel Mijnendonckx, Natalie Leys, Pieter Monsieurs, Daniel Charlier and Rob Van
Houdt A.4 Yeast in a dynamic environment: Understanding robust growth Henning Lindhorst and Steffen Waldherr A.5 Synergistic gelation of protein and polysaccharide at low pH as a potential gel-based delivery system Wahyu Wijaya, Ashok Patel and Paul Van der Meeren A.6 Pocket Power! – increasing the potential of anaerobic digestion at farm-scale Tine Vergote, Anke De Dobbelaere, Bart Ryckaert, Jeroen Buysse, Eveline Volcke and Erik Meers A.7 Effect of cinnamon (Cinnamomum burmanii Blume) essential oils on the textural, rheological, melting
profile and antioxidant activity of white chocolate Dimas Rahadian Aji Muhammad, Valérie Lemarcq, Elien Alderweireldt, Pauline Vanoverberghe and
Koen Dewettinck A.8 Metabolism, absorption and bioactivity of Aronia polyphenols incombined microbial in vitro
digestion/cell culture models Ting Wu, Charlotte Grootaert, Stefan Voorspoels, Griet Jacobs, Judit Pitart, Ilse Scheirlinck, Senem
Kamiloglu, Sam Possemiers, Marina Heinonen, Nevena Kardum, Maria Glibetic, Guy Smagghe, Katleen Raes and John Van Camp
A.9 Investigating the emulsion stabilizing capacity of pectin and protein-rich broccoli serum Jihan Santanina Santiago, Laura Salvia Trujillo, Alex Palomo, Anuj Niroula, Ann Van Loey and Marc
Hendrickx A.10 A discrete element approach for simulating the processing of biomass Mathias Leman, Tom Leblicq, Simon Vanmaercke, Herman Ramon and Wouter Saeys A.11 Germination in psychrotrophic Clostridium botulinum: mechanism and inhibition by natural
antimicrobial compounds Aurélie De Jong, Charlien Clauwers and Chris Michiels A.12 Characterization of phenotypic and genotypic diversity of Sinorhizobium meliloti strains Vincent Greffe and Jan Michiels A.13 Controlling the flow behaviour of dark chocolate formulated with coconut sugar produced by
combination of ball mill and liquefier device Arifin Dwi Saputro, Davy Van de Walle, Maria Paulina González and Koen Dewettinck
48
A.14 Surface behavior of soluble protein fractions from Spirulina platensis Barka Abakoura and Christophe Blecker A.15 Press and Solvent oil extracted from Safou (Dacryodes edulis) pulp: comparison between their
chemical and physical properties. Yamoneka Wasso Juste, Paul Malumba, Sabine Danthine and Christoph Blecker A.16 Interfacial properties of milk fat globule membrane- A langmuir film balance study Priyanka Malik, Sabine Danthine and Christope Blecker A.17 Regression analysis of different sources of dormancy duration value for the potato varieties Margot Visse, Hervé Vanderschuren, Hélène Soyeurt and Brice Dupuis
49
Poster session B: Environment and Agriculture (noon session) B.1 Vulnerability to climate change among maize-based smallholders in three districts of Woliata Zone,
Ethiopia Sisay Belay Bedeke and Natarajan Kolandavel B.2 The contribution of pollinators in the pollination of pome fruits Jolien Smessaert, Olivier Honnay and Wannes Keulemans B.3 Adaptation to climate change among maize-based smallholders in three districts of Ethiopia Sisay Belay Bedeke, Kolandavel Natrajan, Wouter Vanhove and Patrick Van Damme B.4 Suitability of multipurpose trees, shrubs and grasses to rehabilitate gullies in sub-humid tropics Ayalew Legass, Poesen Jean, Muys Bart, Padro Roc, Hirko Dibaba and Diels Jan B.5 Acidogenic fermentation of potato wastes to produce carboxylate platform chemicals: influence of
cations used for pH control on metabolic profile Florent Awedem Wobiwo, Ebenezer Djiazet, Thomas Happi Emaga, Maurice Boda, Elie Fokou, Magali
Deleu and Patrick A. Gerin B.6 A decision support system for maximizing ecosystem services provided by urban green based on
species choice Annelies Calmeyn B.7 Overall situation and influence factors of rural population employment in China: based on 1095
samples from 22 Provinces in 2016 Tian Tian B.8 Comparison of two laboratory-scale ensiling methods to assess effect of reducing sugars Sophie Herremans, Virginie Decruyenaere, Yves Beckers and Eric Froidmont B.9 Adoption of alternative biofuel trees in Karnataka, India: a choice experimental study Floris Dalemans, Bart Muys, Miet Maertens and Anne Verwimp B.10 Particulate matter deposition on urban green: an indicator of habitat quality in cities Ana Castanheiro, Karolien De Wael and Roeland Samson B.11 Biomonitoring of urban air quality: the potential of hyperspectral measurements Jolien Verhelst, Dimitri Dauwe and Roeland Samson B.12 Ecological intensification of fish production : Fertilization strategies in Africa fish farms Mafwila Kinkela Patrick, Kambashi Mutiaka Bienvenu, Rollin Xavier and Bindelle Jerome B.13 Is faecal neopterin a good biomarker for intestinal health in chicken? Mohammad Kamely and Theo Niewold B.14 Parameters related to water balance improve the relationship between the milk urea concentration
and urinary N excretion. Pieter Deckers, Dorien Van Wesemael, Nico Peiren, Veerle Fievez and Leen Vandaele B.15 Relationships between methane emissions from dairy cows and farm technico-economic results.
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Pauline Delhez, Benoît Wyzen, Anne-Catherine Dalcq, rédéric Dehareng, Nicolas Gengler and Hélène Soyeurt
B.16 Controlling aphids on wheat by sowing wildflower strips within field: it’s possible! Séverin Hatt, Thomas Lopes, Qinxuan Xu, Fanny Boeraeve, Julian Chen and Frédéric Francis B.17 Green walls for sustainable buildings and cities: aerodynamic characterisation of vegetation Kyra Koch, Roeland Samson and Siegfried Denys B.18 Assessment of the combined effect of temperature and relative humidity on fungal growth Liselotte De Ligne, Guillermo Vidal Diez de Ulzurrun Jan Baetens, Jan Van den Bulcke and Bernard De
Baets B.19 Identification of a Linuron mineralizing bacterial genus in a BPS material through stable isotope
probing Harry Lerner, Basak Ozturk, Anja Dohrmann, Christoph Tebbe, Kathleen Marchal, Rene de Mot and
Dirk Springael B.20 Differences between the leaf and stem essentials oils of domestic Mentha spicata var. spicata (L.
1753) plants Gabriel Olive and Gilles Olive B.21 Physicochemical characteristics and fatty acid profile of longissimus dorsi muscle of Bni-Guil sheep
breeding in eastern Morocco Kamal Belhaj, Ahmed Elamrani, Mohamed Boukharta and Marianne Sindic B.22 An NFO-LP-model to optimise water allocation in dammed river systems. Jaime Veintimilla, Stefaan Dondeyne, Dirk Cattrysse and Jos Van Orshoven B.23 Physical chemical treatment of landfill leachate: Monitoring and characterization of DOM using
spectral and chemometric techniques. Violet Oloibiri, Sam Deconinck, Michael Chys, Kristof Demeestere and Stijn Van Hulle B.24 Forest policies for sustainable forest management in the Congo Basin. Maximilien Tiogang Djomo B.25 Benthic macroinvertebrate functional feeding groups patterns in Albertine rift rivers relative to
physical variables land-use and physical variables in Southwestern Uganda Peace Liz Sasha Musonge B.26 Simulation of maize crop production by EPICSM model under different irrigation systems in Egypt Hani Mansour B.27 A combined respirometric-titrimetric setup for the development, calibration and validation of a model
describing the microalgal growth rate Dave Manhaeghe, Bjorge Decostere, Diederik Rousseau and Stijn Van Hulle
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Poster session C: Chemistry and Engineering (afternoon session) C.1 A novel surface complexity measure based on the chemical pattern of protein interfaces Tamas Lazar, Mainak Guharoy, Eva Schad, Shoshana Wodak and Peter Tompa C.2 Production of bio-degradable plastics Sofie Winderickx C.3 Characterization of new calpain inhibitors based on an intrinsically disordered protein, calpastatin Hung Nguyen, Mihaly Varadi, Peter Tompa and Kris Pauwels C.4 Improved UV light efficiency using a photocatalytic spiraled reactor design with a plasmonic TiO2
coating Natan Blommaerts, Ramesh Asapu, Silvia Lenaerts and Sammy Verbruggen C.5 Harvesting energy from air pollution with an Un-biased gas phase photo-electrochemical cell Myrthe Van Hal, Tom Bosserez, Jan Rongé, Johan Martens, Silvia Lenaerts and Sammy Verbruggen C.6 An EPR study on the nature of radicals in the B-class dye-decolorizing peroxidase from K. pneumonia Kevin Nys, Vera Pfanzagl, Christian Obinger and Sabine Van Doorslaer C.7 Bioavailability of pomegranate-derived polyphenols in an in vitro model combining luminal digestion
with epithelial Caco-2 cell transport Hanne Vissenaekens, Charlotte Grootaert, Francisco Tomas-Barberan, Judit Pitart, Ilse Scheirlinck,
Rocio Garcia-Villalba, Sam Possemiers, Matthijs Verhille, John Van Camp and Carlos Espín C.8 Confined catalytic Janus swimmers in a crowded channel: geometry-driven rectification transients and
directional locking Vyacheslav Misko C.9 Characterization of a protein family related to Parkinson’s disease Margaux Leemans C.10 Stability of Difference Schemes for Reaction-Diffusion Models of Chemical-Reaction Networks Nathan Muyinda, Bernard De Baets and Shodhan Rao C.11 Nanobody discovery platform: From a llama immune response to tailor-made biological agents. Tomasz Uchanski and Jan Steyaert C.12 Volatile organic compounds in the interaction between Banana plants (Musa sp.) and Panama Disease
Fusarium oxysporum f.sp. cubense Tropical Race 4 (FocTR4) Chadi Berhal, Caroline De Clerck, Carolina Levicek, Francois Verheggen, Marie-Laure Fauconnier and
Sébastien Massart C.13 Injectable peptide hydrogels for controlled drug release Edith Oyen, Charlotte Martin, James Gardiner, Bruno Van Mele, Annemieke Madder, Richard
Hoogenboom, Mariana Spetea and Steven Ballet
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Poster session D: Human health and Genomics and Biotechnology (afternoon session) D.1 Protein intrinsic disorder: a double-edged sword? Mauricio Macossay Castillo, Giulio Marvelli, Mainak Guharoy, Peter Tompa and Shoshana J. Wodak D.2 Role of aquaporins in membrane diffusion of hydrogen peroxide in plant cells upon salt and water
stress Ahmed Ismail and FranÇois Chaumont D.3 Chemical inhibitors of the SOG1 transcription factor to promote aluminium tolerance in maize and
barley Manon Demulder D.4 Using protein interactions to develop new antibiotic production lines Thomas Lathouwers, Birgit Uytterhoeven, Chris Michiels and Rob Lavigne D.5 Elevated CO2 mitigates drought stress in Arabidopsis thaliana: Role of glucosinolates metabolism. Hamada Abdelgawad, Gaurav Zinta, Marios Nektarios Markakis, Gerrit T.S. Beemster and Han Asard D.6 Roles of ERD14 in plant stress responses Phuong Nguyen Nhu, Tran Thanh Thu, Maria Tossounian, Stefanie Clemens, Denes Kovacs and Peter
Tompa D.7 An innovative method to identify interaction partners of the persister protein Obg Pauline Herpels, Jan Michiels, Natalie Verstraeten, Josep Rayo Company and Anastassios Economou D.8 Antibiotic-tolerant persisters contribute to the evolution of genetic resistance Etthel Windels, Joran Michiels, Bram Van den Bergh, Tom Wenseleers, Maarten Fauvart and Jan
Michiels D.9 Development of tools for haploid breeding in Chrysanthemum Chunlian Jin and Danny Geelen D.10 Dermal exposure of Belgian florists to insecticide residues Khaoula Toumi, Laure Joly, Christiane Vleminckx and Bruno Schiffers D.11 Transcriptomic biomarkers in elderly women: Toward understanding age-related hearing impairment Amal Bouzid, Ibtihel Smeti, Amine Chakroun, Abdelmonem Ghorbel, Joel Lachuer, Tim De Meyer and
Saber Masmoudi D.12 Functional display of fusion proteins using the curli biogenesis pathway Imke Van den Broeck, Han Remaut and Nani Van Gerven D.13 Comparative genomics study of Pseudomonas aeruginosa nosocomial strains Cédric Lood D.14 Phylogenetic history and synteny of AT-Hook proteins in monocarpic and polycarpic plant species Rashmi Hazarika and Vera van Noort D.15 Genome-wide transcriptional changes in a polyphagous arthropod pest upon exposure to insecticide
synergists.
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Simon Snoeck, Wannes Dermauw, Richard Clark, Luc Tirry and Thomas Van Leeuwen D.16 Fluorescent probiotic strains for studying microbe-microbe and microbe-host interactions Irina Spacova, Elke Lievens, Tine Verhoeven, Hans Steenackers, Jozef Vanderleyden, Sarah Lebeer and
Mariya Petrova D.17 Exploring the role of suspected pathogens of chronic middle ear pathology and their interaction with
potentially beneficial microbes Jennifer Jörissen, Marianne van den Broek, Sander Wuyts, Ilke De Boeck, Paul Van de Heyning, Vincent
Van Rompaey, Olivier Vanderveken, An Boudewyns and Sarah Lebeer D.18 Targeting Neuropilin-1 through single-domain antibodies: a novel strategy to tackle tumor-associated
macrophages Stefano Bonelli, Damya Laoui, Jiri Keirsse and Jo Van Ginderachter D.19 Molecular characterization of a GntR-like transcription factor involved in heat stress response in
Sulfolobus acidocaldarius Liesbeth Lemmens, Ezra De Koning and Eveline Peeters D.20 Unraveling the metabolic phenotype of tumor-associated macrophages and the impact of metabolic
reprogramming on their functionality. Xenia Geeraerts, Jo A D.21 Fluorescent microscopy combined with Raman-data acquisition and analysis Dmitry Khalenkow D.22 Ly6Clo monocytes promote hepatoregeneration during drug induced liver failure Chloé Abels, Alison Redmond, Mohamed Musrati, Sofie De Groef, Jo Van Ginderachter and Alain Beschin D.23 Improving apple fruit biological control by microbiota using omics tools Abdoul Razack Sare, Haissam Mohamed Jijakli and Sebaastien Massart D.24 16S amplicon sequencing: methods, limitations and a case study Stijn Wittouck, Ilke De Boeck, Sander Wuyts, Eline Oerlemans, Olivier Vanderveken and Sarah Lebeer D.25 BrewPro: Multi-stage microbial technology for the cost-effective production of high-quality animal feed
on brewery effluents. Gustavo Gomes de Sousa and Siegfried Vlaeminck
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MAP