Question

Name the scientist who discovered the process of fermentation.

Answer 1

Hint: The early studies related to fermentation eventually established that it involves yeast and other microbes breaking down molecules of complex carbohydrates into simpler sugars, alcohols, and $CO_2$.

Complete answer:
‘Louis Pasteur' discovered the process of fermentation.
- Fermentation refers to the metabolic process by which organic molecules (normally glucose) are converted into acids, gases, or alcohol in the absence of oxygen with the help of microorganisms. It takes place in yeast, bacteria, muscle cells, etc. Example- lactic acid fermentation, acetic acid fermentation, alcohol fermentation, etc.
- Fermentation is complementary to the process of glycolysis and allows ATP to be continually produced in the absence of oxygen. Fermentation regenerates NAD+ by oxidizing the NADH produced in glycolysis which can take part in glycolysis once again in order to produce more ATP.
- In 1857, Pasteur showed lactic acid fermentation in living organisms, namely yeast. He proved that living cells, the yeast, were responsible for forming alcohol from sugar. In 1860, he demonstrated that bacteria cause souring in milk, and this work led to the discovery of the process of pasteurization.

Additional Information:
Important contributions of Louis Pasteur are as follows:
- He developed the methods and techniques of bacteriology.
- He introduced the live attenuated vaccines for Anthrax for the first time.
- He coined the term ‘vaccine'.
- He is credited with the introduction of sterilization techniques and the development of steam sterilizer, autoclave, and hot air oven.

Note:
- In lactic acid fermentation, starch or sugar is converted into lactic acid.
- In alcoholic fermentation, Pyruvate, the end product of glycolysis is broken down into alcohol and carbon dioxide. Wine and beer are produced by alcoholic fermentation.
- In acetic acid fermentation, starch and sugar present in grains and fruits ferment into vinegar. For example, apple cider vinegar.