1

Microbes:Organic acid Producers

Production generally fermentation

TCA Citric acidGlucose Gluconic acidpiruvate/ethanol Acetic acid & Lactic acid

-Additive for food industry- chemical Industry

2

Citric acid

Natural substance of plant1893 : found fungi producing citric acid1928: first production using fermentation surface fermt

Extact of lemon contain 7 –9 %Now 99 % production using MO fermentation

- 1929 : 5000 ton-1952 : 50 000 ton-1976 : 200 000 ton-1979 : 220 000 ton

60 % : food industry( juice, candy, ice cream)25 % : chemical industry(antifoam, softener, etc.)10 % : pharmaceutical industry (Fe-citrate: blood preservative)

Microbes: -Aspergillus niger-A. wentii-A. clavatus-Penicillium luteum-P. citricum-Mucor piriformis-Candida quilliermondii-Tricoderma viride-Corinebacterium sp.

Biosynthesis:Via TCA:No expression of α-ketoglutarat dehidrogenase

3

Production:

4

5

Surface Fermentation:

Solid Medium :onggok, singkong, gandumshelf : 3 – 5 cmtemp 28 Ctime: 5 – 8 daysExtracted using hot water

Liquid Medium :the oldest production20 % of total world productionstill appliedtime: 5 – 8 daysExtracted using hot waterTemp 30 C

6

7

Submerged Fermentation:80 % of citric acid productionvolume 120 –220 m3

time: 8 days

purification:Control not optimumproduced oxalic acid

oxalic acid precipitated at low pHLow pH, citric acid still disolvedpH 7,2; temp 70 –90 Ccitric acid precipitatedPurification using Sulphuric acidcitric acid still disolved

; CaSO4 precipitated

Active Carbon & kation/anion exchanger

Crystallisation:temp 40 C : crystal anhidratetemp < 36,5: crystal monohidrat

Gluconic Acid:

-industry : - metal- Kulit- food- deterjen

-1911: produced by Pseudomonas (Alsberg)-1928: Fungi surface fermentation

Penicillium luteum-purpureum (yield 80-87 %)-Now production: submerged fermentation

A. niger

Other MO :-Penicillium-Scopulariopsis

Acetobacter suboxydans

- Vibrio- Pseudomonas

-Gonatobotrys-Pullularia

8

9

Production:

-Ca-gluconic : low solublelity ( 4 g/l; 30 C)[sugar] 13 – 15 %[sugar] high spontaneuos cristalisationpurification dificult

-Na-gluconic : solublelity 396 g/l[sugar] 28 – 30 %

Time of fermentation: 36 hourstemp 28 – 30 CAeration: 1 – 1,5 vvmPressure affecting to production

10

Acetic Acid:

-MO : 2 genus : Gluconobacter: ethanol acetic acidAcetobacter: over oxydation

ethanol acetic acid CO2 + H2O

- production ~ wine production 10000 years ago ( Roman, Greek)-Drinkvinegar

wine left open

MO :-A. aceti-A. pasteurianus-A. peroxydans-G. oxydans

*many sp can be used for production except A. xylinum

11

Production:

-Surface Ferm. : trickling generatorvol 60 m3

weed particles+ MO88 – 90 % ethanol converted to acetatetemp 29 Ctime 3 days

12 % acetate

-Submenrged Fermentation:vol 50 m3

acetate production: 13 %temp 30 Caeration 3 – 4 vvhproduction 10 times higher

than lebih surface ferm.

12

Lactic acid:- the first organic acid produced 1880-Production: chemical & fermentation

-2 types of lactic acid bacteria:1. Heterofermentative: producing several organic acids2. Homofermentative: producing only lactic acid

MO:-Lactobacillus debrueckii-L. bulgaricus-L. pentosum

Production:-glucose-(NH4)2HPO4

12 – 13%0,25 %

- + Vit. B-Vol= 25 – 120 m3

-time: 72 hours-pH 6,3 – 6,5

13