1. 1 Microbes:Organic acid Producers Production  generally fermentation TCA  Citric acid Glucose  Gluconic acid piruvate/ethanol  Acetic acid & Lactic acid -Additive for food industry - chemical Industry

2. 2 Citric acid  Natural substance of plant  1893 : found fungi producing citric acid  1928: 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. 3 Production:

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5. 5 Surface Fermentation: Solid Medium :  onggok, singkong, gandum  shelf : 3 – 5 cm  temp 28 C  time: 5 – 8 days  Extracted using hot water Liquid Medium :  the oldest production  20 % of total world production  still applied  time: 5 – 8 days  Extracted using hot water  Temp 30 C

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7. 7 Submerged Fermentation:  80 % of citric acid production  volume 120 –220 m 3  time: 8 days purification: Control not optimum  produced oxalic acid  oxalic acid precipitated at low pH  Low pH, citric acid still disolved  pH 7,2; temp 70 –90 C  citric acid precipitated  Purification using Sulphuric acid  citric acid still disolved  ; CaSO 4 precipitated Active Carbon & kation/anion exchanger Crystallisation:  temp 40 C : crystal anhidrate  temp < 36,5: crystal monohidrat

8. 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. 9 Production: -Ca-gluconic :  low solublelity ( 4 g/l; 30 C)  [sugar] 13 – 15 %  [sugar] high  spontaneuos cristalisation  purification dificult -Na-gluconic :  solublelity 396 g/l  [sugar] 28 – 30 %  Time of fermentation: 36 hours  temp 28 – 30 C  Aeration: 1 – 1,5 vvm  Pressure  affecting to production

10. 10 Acetic Acid: -MO : 2 genus :  Gluconobacter: ethanol  acetic acid  Acetobacter: over oxydation ethanol  acetic acid  CO 2 + H 2 O - production ~ wine production  10000 years ago ( Roman, Greek) -Drink  vinegar  wine left open MO : -A. aceti -A. pasteurianus -A. peroxydans -G. oxydans *many sp can be used for production except A. xylinum

11. 11 Production: -Surface Ferm. : trickling generator  vol 60 m 3  weed particles+ MO  88 – 90 % ethanol converted to acetate  temp 29 C  time 3 days  12 % acetate -Submenrged Fermentation:  vol 50 m 3  acetate production: 13 %  temp 30 C  aeration 3 – 4 vvh  production 10 times higher than lebih surface ferm.

12. 12 Lactic acid: - the first organic acid produced  1880 -Production: chemical & fermentation -2 types of lactic acid bacteria: 1. Heterofermentative:  producing several organic acids 2. Homofermentative:  producing only lactic acid

13. MO: -Lactobacillus debrueckii -L. bulgaricus -L. pentosum Production: -glucose -(NH 4 ) 2 HPO 4 12 – 13% 0,25 % - + Vit. B -Vol= 25 – 120 m 3 -time: 72 hours -pH 6,3 – 6,5 13