2. Content:
Organic Acid
Citric Acid
Methods Of Citric Acid Production &
Raw materials
KOJI Fermentation Process
Submerged Culture Fermentation Process
Liquid Surface Culture Fermentation Process
Fermentation Of Citric Acid by Microbes
Recovery and Purification
Uses Of Citric Acid
3. Organic Acid
• Organic acid are the organic compound with acidic
properties.
• The most common organic acids are the carboxylic
acids.
• Acidity is associated with their acid groups like-
carboxylic group (-COOH)
• Organic acid are the terminal products of glycolysis.
• For eg. Lactic acid
• These are the products of incomplete oxidation of
sugar.
Such as, , gluconic acid.
4. Citric Acid
• It is tricarboxylic acid, having
formula C6H8O7.
• It is first reported by “Carls
scheel” (1789-England) in
lemon juice.
• It occurs naturally in citric
fruits.
• It is a natural preservative and
used to add an acidic taste to
food & soft drinks.
5. conti
• It exists in a variety of fruits and vegetables ,
most conc. In lemon ,orange (7-8%).
• It is an intermediate of citric acid cycle.
• Commercially production of citric acid is
generally by submerged fermentation of
sucrose or molasses using the filamentous
fungus Aspergillus niger.
6. History :
• 1789 – Carl Scheele
• 1893 – Wehmer
• 1916 – Currie
• 1930 – some unit implanted in England ,
Germany for the commercial
production.
7. Methods Of Citric Acid Production
& Raw materials
Submerged Culture Fermentation Process
Liquid Surface Culture Fermentation Process
KOJI Fermentation Process1
2
3
8. Submerged Culture Fermentation Process
(Liquid Fermention)
• This is commonly used for citric acid production.
• It estimate about 80% .
• Less prize
• Small size
• High yield
• Low labour cost
Two types of fermentor are used-
Conventional stirrer
Tower fermentation
10. In this process
Raw material – sugar , starch
Treatment (if require)
Mycellia of aspergillus japonicum
flow about 15cm deep in tank
10% of fresh medium is required
It takes 5-10 days
11.
12. Liquid Surface Culture Fermentation
Process
(surface fermentation)
• The first individual process for citric acid
production.
• It is introduce by “Des” in 1919
• Later “Chas” in 1923
• Sophisticated technique
14. In this process
• Liquid culture are incubated with spores
• Mycellia mat developed on the surface of
medium.
• It takes 24hrs.
• Crude sucrose, cane syrup & beet molasses
are used as carbon source.
15. KOJI Fermentation Process
(Solid state fermentation)
• It is an alternative method.
• This method is used first in JAPAN
• Aspergillus Niger Strain is used in this method.
• It is the simplest method .
• It can carried out using several raw
material(Table).
16.
17. In this process
Substrate is moistened about 70%
acc.to capacity.
pH is maintained about 4.5-7.0
Temp. 28-30*C
It takes place in simple tray type
fermentor
Higher yield obtained ,without any
aeration and sporulation obseved
very little
