In simple words, fermentation is a process in which the production of organic substances happens. However, the production of such organic substances is through the activity of microbial organisms. Acetic acid, whose common name is vinegar, is also a product of such microbial activity. So, The formation of vinegar is through acetic acid fermentation. The fermentation of acetic acid is one of the oldest fermentation techniques in humankind. So, in this article let us study deeply about this age-old process.
Useful microorganisms in the fermentation of acetic acid
The two most valuable and essential microorganisms in the fermentation are- acetobacter and yeast. Also, these micro-organisms work together to form products of fermentation. The main organisms for the formation of acetic acid multiply at the top of the surface. Moreover, “Mother of Vinegar” refers to these organisms growing at the top. Furthermore, these microbes form a jelly-like mass.
The most useful bacteria for the fermentation of acetic acid is acetobacter aceti. However, other bacteria like gluconacetobacter and gluconobacter are also helpful. Moreover, the essential yeast for fermentation is saccharomyces cerevisiae. The most important thing to keep in mind during the fermentation is the acidic environment. The acidic acid reduces the growth of unwanted organisms. Moreover, it increases the wanted bacteria for fermentation.
Fermentation of Acetic Acid
To produce acetic acid, we need to follow two processes:
- We must use the yeast that converts glucose or sugar to alcohol.
- We use acetobacter and other bacteria to convert ethyl alcohol to acetic acid.
- To oxidise ethanol to acetic acid, a massive amount of oxygen comes to need.
To convert ethanol to acetic acid, oxidation steps take place. These steps convert to acetaldehyde and then acetic acid. So, the ethanol produced earlier undergoes conversion to form acetaldehyde in the first step. The first step takes place when NAD and NADP are present. Then the second step consists of converting acetaldehyde to form acetic acid.
In this natural method of fermentation, the production of almost one litre of twelve percent acetic acid occurs. This formation of one litre is from 1 litre of twelve percent alcohol.
Commercial method of Acetic Acid Fermentation
Do you wonder how the fermentation of acetic acid is done in industries? Well, it is time to get you your answer.
There are two methods of commercial fermentation
- Surface fermentation process.
- Submerged fermentation process.
Here is an elaborate explanation of both techniques.
Surface Fermentation
In the commercial production of acetic acid, generators are used. So, the generator useful in this process is the trickling generator. This generator has a lining of birch wood shavings on its innermost surface. To begin with, the ethanol passes through the generator from the top. This ethanol trickles through the birch wood shavings. Also, these shavings contain essential bacteria. This solution reaches the button basin, cools down, and is pumped again. The process repeats until about 80-90% of ethanol conversion occurs.
However, a few things should be kept in mind. The material, in the beginning, should have ethanol and acetic acid. Its requirement is for the proper growth and multiplication of acetobacter.
Submerged Fermentation
This method of fermentation is more beneficial. Moreover, the production of ethanol is higher. Also, one needs to invest much less in this method. In addition, the manual need is significantly low as it is almost completely automatic.
In this method, we get 13% acetic acid which is more than the other method. The useful fermentor in this method is steel. Moreover, the stirring mechanism is at the bottom of the fermentor. Aeration is through the suction rotor. Furthermore, the air enters the fermentor from the top through a pipe. A heat exchanger is also present to control the temperature. The starting material should have ethanol and acetic acid. Further, the concentration of ethanol should be 5%.
The process of fermentation in this method takes about 35 hours. Moreover, the temperature should be forty degrees celsius. Around 98% acetic acid is formed from this method.
Products of acetic acid fermentation
The product of the fermentation of acetic acid is vinegar. This vinegar is useful in cooking. However, vinegar had other purposes as well. It is also useful in cleaning and removing moulds. Moreover, the intermediate product of fermentation is acetaldehyde.
Solved questions of fermentation of acetic acid
- What is the intermediate product in the fermentation of acetic acid?
The intermediate product in the fermentation is acetaldehyde.
- Which bacteria are useful in the fermentation of acetic acid?
Acetobacter aceti is the most important bacteria for fermentation. Other bacteria are gluconacetobacter and gluconobacter. Yeast is also essential.
Conclusion
Lastly, fermentation is useful for the formation of vinegar. Moreover, the fermentation of acetic acid is one of the oldest techniques in humankind. Furthermore, the fermentation is through the activity of microorganisms.