The document discusses the production of acetic acid. It describes the key steps in acetic acid production which include the conversion of starch to sugar, ethanol fermentation, conversion of ethanol to acetaldehyde, and finally the production of acetic acid. The main microorganisms used are acetic acid bacteria such as Acetobacter aceti. Three main methods of production are described - Orleans, surface fermentation, and submerged fermentation. The document also outlines applications and uses of acetic acid.

1. Y5E02 BIOPROCESS
TECHNOLOGY – Unit IV –
Acetic acid Production
Dr. S. SIVASANKARA NARAYANI
ASSISTANT PROFESSOR
DEPARTMENT OF MICROBIOLOGY
AYYA NADAR JANAKI AMMAL COLLEGE
SIVAKASI

2. UniT -IV
• Microbial production technology: antibiotics (penicillin) - organic acids (citric acid and acetic acid) - vitamins (b12 and
riboflavin) - *enzymes (amylase) - alcoholic beverages (beer and wine). Single cell protein.
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3. Acetic acid
• Acetic Acid is systematically named as ethanoic acid
• It is a colorless liquid organic compound.
• It has a pungent/ vinegar-like odor
• Vinegar is product of Acetic acid
• It has melting point 16 to 17°C; 61 to 62°F
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4. History
• Acetic acid production is as old as wine making(10,000 years).
• In 3rd centaury Greek philosopher described how vinegar acted on metals to produce pigments useful in art.
• Ancient Romans boiled sour wine in lead pots to produce highly sweet syrup called sypa.
• In 8th centaury Persian chemist Jabir Ibn Hayyan concentrated Acetic acid from vinegar through distillation
processes.
• In 1847 German chemist Hermann Kolbe synthesized acetic acid from inorganic materials for first time.
• By 1910 most of the acetic acid was obtained from the from distillation of wood.
• At this time Germany is producing 10,000 tons of acetic acid.
• About 30% of which is used for the manufacturing of indigo dyes.
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6. Acetic acid bacteria
• Acetic acid bacteria is a gram-negative bacteria which oxidize sugar or ethanol
and produce acetic acid during fermentation.
• Acetic acid bacteria are rod-shaped & obligate aerobes.
• Pasteur in 1864 claimed that the transformation of wine into vinegar was due to
the veil of Mycoderma aceti on it surface pungency of acetic acid.
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7. Bacteria
• Acetic acid bacteria are commonly used for the production of acetic acid.
• The three important genera's are..
• 1 -Genus acetobacterium:
• The commonly used species are. Acetobacterium aceti Acetobacterium xylinum
• 2- Genus clostridium: the commonly used species is Clostridium
thermoaceticum…which is an anaerobic thermophile.
• 3-Acetic acid bacteria: Acetobacter and Gulocanobacter are commonly used,
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8. Raw materials
• Biomass Feedstock (beach wood, Silicon tube, sieving, wood chips)
• Ethanol is used as substrate.
• Microbes Acetic Acid Bacteria (Acetobacter aceti ) used as bio reactor
• Following substrates are commonly used.
• Ethanol
• Wine and whey
• Molasses
• Fermented grains
• malt and rice.
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9. Production
• Acetic acid is produced in following four steps.
• Conversion of starch to sugar by using amylases enzymes.
• Anaerobic conversion of sugars to ethanol by yeast fermentation.
• Conversion of ethanol to hydrated acetaldehyde.
• Finally by dehydrogenation acetic acid is produced by using aldehyde
dehydrogenase enzyme
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10. Biosynthesis
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11. Types
Acetic acid is produced industrially by following three methods..
• i. Orleans
• ii. Surface fermentation(trickling generation method).
• iii. Submerged fermentation methods.
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12. Orleans
• Old and traditional method.
• Slow but continuous processes.
• High grade vinegar is used as starter culture.
• Fermentation is done on large containers.
• Filled to two-third of its capacity.
• Wooden containers are laid down on their sides and holes are drilled at top and end
sides of barrel.
• Then ethanol is poured in to container using long necked funnels from top.
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13. Cont…
• Then add starter high grade vinegar.
• Ethanol convert in to acetic acid within five weeks.(35 days).
• Netting or screens are placed over holes to prevent insects getting entry in to barrels,
• The barrel's are allowed to sit for several months.
• The temperature is kept at 21-29 degree centigrade.
• Samples are taken periodically by inserting spigot in to side holes.
• When alcohol is converted to acetic acid, it drown off through spigot.
• About 15% liquid is left to blend with next batch.
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15. Trickling generation or Surface fermentation
• Also known as trickling system or germen processes.
• Most commonly used industrial method for production of acetic acid.
• Surface fermenter or barrel is filled with vinegar-moistened beech wood shavings.
• The substrate alcohol is poured from top of container and slowly drip down through
the shaving fillings.
• Oxygen is allowed to container through two routes.
• i. One through holes that have been punched into sides of vat.
• ii. Second through perforated bottom of vat.
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16. Cont…
• Air is introduced through holes by air-compressors.
• When alcohol reaches to bottom of vat , usually within a span of three days it has been
converted in to acetic acid.
• Following condition are kept under control.
• P.H range 2.5-3.2
• Temperature is kept between 20-30 degree C.
• 80-88% vinegar will be produced.
• ADVANTAGES : • Low cost • Ease of control. • High acetic acid concentration. • Less space
requirements.
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18. Submerged method
• This method is newer , faster and more efficient.
• For industrial processes, 10–18% ethanol and 5 times the nutrients used for submerged
fermentation are the starting conditions for fermentation.
• When the concentration of ethanol reaches 50–60% of the solution is removed and replaced
with fresh substrate containing 10–18% ethanol.
• Production plant is filled with large stainless steel containers called acetetors.
• Acetators are equipped with centrifugal pumps at bottom that will pump air bubbles in to
tank.
• As pump stirrers alcohol , the nutrients enhance the growth of acetobacter on oxygen bubbles
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19. Cont…
• Heat jackets keeps the temperature between 40 -42 degree centigrade.
• In 72 hours ethanol is converted to acetic acid
• The vinegar is piped from Acetator to plate and then frame to filtering machine.
• The stainless steel plates press alcohol through pipe filters to remove any sediment ,
usually about 3% of total product.
• The sediment is flushed in to drains while filtered vinegar move toward dilution
station.
• Advantages • Higher productivity. • Faster oxidation of ethanol. • Low cost due to
automation.
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21. Purification
• The isolation, purification and concentration of final product determine the
feasibility of the processes.
• A. Cell separation and cell lysis:
• the first operation is cell separation and cell lysis. Which can be done by using
following techniques.
• Cross-flow microfiltration
• Nano-filtration
• Electro.diaylasis “these techniques are useful to concentrate the glacial acetic acid”
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22. Application
• Common use:
• Used as solvent in different industrial processes.
• Used as an active ingredient in fragrance and perfumes.
• Used in production of synthetic fibers and textiles.
• Used to make ink and indigo dyes.
• Used in manufacturing of rubber and plastics.
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23. Cont..
• In medicinal industry:
• Acetic acid in the form of vinegar is used for preservation of food.
• Soothe sunburnt skin and to cure from jellyfish stings. •
• Effective tool for cervical cancer screening.
• In Health and hygiene: added in to.. • Hair conditioners • Detangles and
deodorant.
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24. Cont..
• House Hold cleaning:
• acetic acid in the form of white vinegar is used variety of cleaning tasks. •
• Removing smears and streaks from mirrors. •
• To descaling coffee making machines. •
• Remove urine odor and pet stain.
• Food flavoring: • Used as a condiment to produce pickles. • Used as a flavor
enhancer. • To preserve vegetables • In manufacturing of mint sauce and
production of rice.
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25. clarification
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sivasan91@gmail.com
sivasan_sf549@anjaconline.org

26. Questions to think
• What are the main things needed for acetic acid production?
• Acetic acid biosynthesis
• Steps involved in the production process of acetic acid
• Methods involved in the aceticacid production
• Pointout the use of acetic acid
• submerged and surface fermentation production of acetic acid - specify
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