S290 Special Abstracts / Journal of Biotechnology 150S (2010) S1–S576

The present work was undertaken in order to investigate the dyedecolorizing potential of Bacillus Sp. to decolorize indigo dye.

The decolorization potential of Bacillus Sp. isolated from anindustriel wastewater treatment plant showed that it was the mostefficient in decolorizing indigo dye. The culture exhibited goodpotential ability in decolorizing indigo dye when present as a mix-ture at 100 mg/L. The new isolated Bacillus Sp. exhibited excellentresistance and decolourisation ability to indigo.

Biodecolorization ability of the newly isolated bacillus waschecked for different concentrations of indigo. The culture wasfound to be effective on indigo resulted in 70–90% colour removalin 12 h of incubation (data not shown) and 90–98% decolourisationin 24 h. The decolorization of indigo was studied under static andagitation conditions with an initial dye concentration of 100 mg/L.Under shaking condition the culture though showed faster growthand decolorization. The results clearly indicated that decoloriza-tion was dependent on biomass concentration and was significantlycorrelated with dissolved oxygen. The study of the mechanism ofindigo removal showed that was attributed to biodegradation.

The main absorbance peak approximately disappeared withinfew hours, followed by an insignificant change in peak for next24 h. In addition, extra absorbance peaks appeared in decolorizedsolution, probably resulting from the absorbance of metabolitesor degraded fragments of dye molecules. The feasibility of repet-itive uses of suspended culture for decolorization was investigatedwith repeated-batch operations. For intact cultures, there has beena marked rise in the specific decolorization rate (SDR). The cultureexhibited stable decolorization activity and significant acclimationdue to this increased SDR for each cycle.

doi:10.1016/j.jbiotec.2010.09.232

[P-E.211]

Application of tannery organic wastes in degraded soils reme-diation

G. Zainescu 1,∗, P. Voicu 1,2, A. Gherghina 1,2, L. Sandru 1,3

1 Leather and Footwear Research Institute, Romania2 Research Institute for Soil Science and Agrochemistry, Romania3 Research Institute for Plant Protection, RomaniaKeywords: biopolymer; organic wastes; tannery; soil

Recent studies carried on in Central and Eastern Europeshowed that in these countries, the main degradation processesinduced by human activity consist in reduced soil fertility, crust-formation, water and wind erosion, landslides and chemicalpollution.Conservation of soils and their fertility in equilibrium tonatural processes represent an essential requirement for ensuringfood safety for a growing population.

The use of untanned wastes presents a special interest, becauseit provides almost total fleshing waste discharge while obtainingqualitatively and economically valuable products. The main targetof this scientific paper is investigating the development possibili-ties for various multicompound systems of biodegradable polymersand studying the effects of these complex products on the structureand chemical and physical characteristics of degraded or contami-nated soils (having a poor level of organic matter or submitted to astrong erosion process).

Organic biopolymers represent a source of raw material foragriculture, because the composition of protean wastes providesenough elements to improve composition and rehabilitation ofdegraded soils, and plants can capitalize some elements: nitrogen,calcium, magnesium, sodium, potassium etc.

The work presents a new pilot technology for biochemical decayof the tannery protein wastes and use of the resulted products asfertilizers. The project will contribute both to agricultural rehabili-tation of poor and degraded soil and to decreasing and capitalizingprotein wastes that are actually discharged at waste dumps.

doi:10.1016/j.jbiotec.2010.09.233

[P-E.212]

Sustainable agricultural crop production by endophytic acti-nobacteria

Christopher Franco

Flinders University, Australia

We have successfully developed a new sustainable methodusing endophytic microorganisms to enhance agricultural produc-tivity. In our work we have screened and developed endophyticactinobacteria as inoculants to increase grain yields of cereal cropsin broadacre cultivation. These endophytic filamentous bacteria,which inhabit the internal tissues of most plants were isolated usingselective media to obtain a diverse range of genera, and screenedfor strains with beneficial properties such as control of fungal rootdiseases and plant growth promotion. Actinobacteria are ideal part-ners as they are prolific producers of useful ‘interactive’ secondarymetabolites. We hypothesized that endophytes will be more reli-able and effective than other inoculants as they work inside theplant.

We have identified endophytic actinobacteria that work withinplants to enhance crop yields and improve crop establishment andplant growth – this has been proven to occur via number of modesof action such as nutrient acquisition, production of growth hor-mones, direct antagonism of fungal pathogens via antibiosis or theinduction of systemic defense responses. Molecular methods wereused to identify endophytic bacterial populations within a rangeof crop plants. We have provided microscopic evidence of coloni-sation to show their endophytic status. These studies reveal howthese microorganisms enter and migrate through the plant host.Current studies are identifying the plant –microbe interactionsthat are mediated by genes on a 13kB plasmid, and bv proteomicapproaches.

Field trials were carried out to select elite strains of endophyticactinobacteria with the ability to control fungal root diseases affect-ing cereal crops such as wheat and barley over a 5 year period. Theseelite strains of endophyte actinobacteria increased grain yields bybetween 5-60% compared to the untreated controls, in the presenceof Rhizoctonia, Gauemannomyces and Crown rot diseases.

These actinobacterial inoculants can be cultivated in vitro on alarge scale and applied as spores to seed at sowing. The applica-tion of the endophyte inoculant does not significantly change themicrobial populations within the plant or in the rhizosphere.

Endophytic actinobacteria are natural resources that are effec-tive and reliable for use in agriculture and are a sustainablebiotechnology resource to secure and improve grain yields. Thistechnology is being commercialized and opens a new paradigmthat can also be applied to inc pasture production, horticulture andfloriculture.

doi:10.1016/j.jbiotec.2010.09.234