Acid production

CITRIC ACID PRODUCTION
ACETIC ACID PRODUCTION
GLUCONIC ACID PRODUCTION

1. ACID PRODUCTION SUBMITTED BY RESHNA K R 3 SEMESTER MSc BIOTECHNOLOGY

2. CITRIC ACID PRODUCTION ACETIC ACID PRODUCTION GLUCONIC ACID PRODUCTION

3. CITRIC ACID PRODUCTION Occur naturally Compound of fruits Also produced by fungal fermentation No chemical synthesis competitive with the fungal fermentation

4. uses Employed as an acidulent in the food and pharmaceutical industries Production of carbonated beverages Chelating and sequestering agent Citrate and citrate esters are used as plasticizers

5. Citric acid accumulated during controlled fermentative growth Commonly used fugal sp are Penicillium Aspergillus ( during World War 1 ) Aspergillus niger in carbohydrate medium – large amount of citric acid

6. Aspergillus niger positive Characteristics of citric acid yield Amount of sporulation Strain stability Negative Lack of ability to degrade the citric acid product Lack of concurrent formation of other acids of oxalic, gluconic, malic and 5-ketogluconic

7. Fermentation medium Nutrient deficiency in the form of trace metals Phosphate is slightly deficient deficient of one or more metals iron, zinc, probably copper Manganese particularly important The concentration of metals in medium is interrelated

8. Methanol – added to the medium slightly toxic level , not metabolize Increase tolerance of fungus to zinc, iron and manganese Beet molasses – 10 – 20% sugar Ammonium nitrate, magnesium sulfate and KH 2 PO 4 Hydrochloric acid – adjust the medium to a low pH value Beat molasses – contain too great quantity of trace metal

9. Excess is reduced – pretreatment with ferrocyanide or ferricyanide , cation exchanger CITRIC ACID FERMENTATION TECHNIQUES Submerged aerated techniques Stationary pans or trays containing a shallow layer of medium (commercially used)

10. Medium is inoculated by blowing spores across the surface of a shallow layer of medium Air is changed at intervals to provide additional aeration Aeration cause contamination Harvest – 7 – 10 days of incubation 60 – 80 g / greater of anhydrous citric acid per 100 g of added sugar

11. Replacement culture can be employed for both stationary tray fermentation and submerged – aerated fermentation Sugar utilized are greater when the mycelium is not reused

12. Difficult to recover from harvested fermentation Complicated by the presence of unfermented sugar, other acid fermentation product, inorganic impurities Precipitation of citric acid as calcium citrate from hot neutral aqueous solution Addition of sulphuric acid to remove the calcium as calcium sulphate

13. ACETIC ACID PRODUCTION Term vinegar originated from French word vinaigre (sour wine) Formation of Vinegar involves souring of wine under specific condition Two stages Alcoholic fermentation Acetic acid fermentation

14. Alcoholic fermentation Sugar containing materials are fermented to ethyl alcohol Sugar containing materials – fruit juice, honey or hydrolyzed starchy materials Bioconversion is brought by enzyme of yeast Strain – saccharomyces cerevisiae 1g glucose yield 0.5114g of ethyl alcohol Fermentable sugar concentration – 8- 20% Necessary to add potassium and ammonium phosphate Crushed grape, grape juice, apple juice – mineral salt not needed

15. Two stages Primary stages – last from 3 to 7 days Contacted in open fermentation Secondary stages - several weeks Carried out in closed fermenter Sulfur dioxide is added – inhibit growth and activity of unwanted yeasts and bacteria (50 – 1oo mg) Yield of alcohol 85-90%

16. Acetic acid fermentation Microbial conversion of dilute ethanolic solution to acetic acid Orleans process – acetic acid bacteria grow vary slowly as a film over the surface of liquid Produce finest culinary vinegar Quick vinegar process – introduced in last century Deep fermentation process – quick vinegar process Industrial importance

17. Quick vinegar process Use frings generator Air tight tank – 14 ft diameter, 15 ft height Wooden grating near bottom Sprayer or distributing arm is fitted near top of the tank Top 4 inch vent, with damper connected to a vapour – liquid separator Control the air supply 10 air intakes (contain air filter) Situated around tank near level of wooden grate

18. Control the temperature – cooling coills Generator packed with beechwood shavings 1.5 ft

19. Acetic acid bacteria – Acetobacter sp Inoculate in beech wood shaving Vinegar stock is allowed to undergo circulation Undergo more oxidation Continues until vinegar of desired strength has been obtained

20. factors Nature of packing material Nature of vinegar stock used Rate of flow of ethanolic solution Rate of air flow & temperature

21. Packing material – beech wood shaving , coke, pumice, rattan, grape Sliming is caused by the development of the so called mother of vinegar Deep fermentation process Acetobacter acetigenum and A. pasteurianum 76 - 82ºF 20 litres air introduced per hour pH – 3.9-5

22. Medium Corn sugar Diammonium hydrogen phosphate Autolysed yeast Citric acid Powdered whey Potassium chloride

23. GLUCONIC ACID PRODUCTION Uses Calcium gluconate employed as pharmaceutical to supply calcium Calcium and sodium gluconate in alkaline solution good metal sequestering agent for iron, aluminium and copper Ferrous gluconate supplies iron for the treatment of anemia

24. Gluconic acid producing strain Pencillium sp Aspergillus sp (commercially using) Aspergillus niger – one step enzymatic transformation of glucose to gluconic acid

25. 2 metod Stationary Submerged Submerged culture presently used in industrial production Initial fermentation produces the mycelium – pure enzymatic transformation Reuse of mycelium – lessening the requirement for inoculum build up

26. Growth medium 25% glucose Calcium carbonate Boron compound- stabilize calcium gluconate, prevent precipitation Cornsteep liquor 30ºC aeration and agitation Heat evolved controlled by cooling coil, water jacket Medium does not contain nitrogen – prevent further growth of mycelium

27. Termination of either the growth or replacement culture fermentation Recovered by neutralization of broth with calcium hydroxide Crystallization of calcium gluconate Free gluconic acid recovered from the calcium gluconate by the addition of sulfuric acid

28. Absence of boron – maximum suger content fermented High sugar level – excess calcium gluconate Free gluconic acid in medium – injures mycelium More recent – sodium instead of calcium