Types of Fermentation - Definition, Process, Examples, Advantages

Types of Fermentation: Understanding fermentation is essential for NEET students, as it forms a critical part of the biology syllabus, particularly in units dealing with cellular processes. This article simplifies the concept of fermentation, outlining its types, processes, and advantages to help you grasp the subject thoroughly.

NEET Biology Notes

Fermentation Definition

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Types of Fermentation

1. Alcoholic Fermentation

Mammary Glands

2. Lactic Acid Fermentation

Okazaki Fragments

3. Acetic Acid Fermentation

4. Butyric Acid Fermentation

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5. Mixed Acid Fermentation

Sexual Reproduction in Flowering Plants

Fermentation Process

1. Anaerobic Conditions: Fermentation occurs without the presence of oxygen. Cells switch to fermentation to generate usable energy under anaerobic conditions.
2. Glucose Breakdown: The process begins with the breakdown of glucose. This sugar is converted into simpler molecules, releasing energy that is stored in ATP (adenosine triphosphate) molecules.
3. Product Formation: Depending on the type of fermentation, various end products are formed such as ethanol, lactic acid, or hydrogen gas.

Blue Green Algae

Fermentation Examples

Alcoholic Fermentation Examples

• Beer Brewing: Yeasts, primarily Saccharomyces cerevisiae , ferment malted barley to produce beer. The sugars in the malted barley are converted into alcohol and carbon dioxide.
• Wine Production: In winemaking, yeasts ferment the natural sugars found in grapes. The process varies slightly depending on the type of wine being produced but fundamentally relies on alcoholic fermentation.
• Ethanol Fuel: Ethanol for fuel is produced using alcoholic fermentation on a large scale, often using biomass such as corn, sugarcane, or cellulose.

Systole and Diastole

2. Lactic Acid Fermentation Examples

• Yogurt: Lactic acid bacteria ferment lactose, the sugar in milk, into lactic acid which acts on milk protein to give yogurt its texture and tangy taste.
• Sauerkraut: The fermentation of cabbage by lactic acid bacteria, mainly Leuconostoc , Lactobacillus , and Pediococcus , results in sauerkraut, a dish noted for its distinct sour flavor.
• Kefir: A fermented milk drink similar to a thin yogurt, kefir is made by fermenting milk with kefir grains, which contain a complex mixture of lactic acid bacteria and yeasts.

3. Acetic Acid Fermentation Examples

• Vinegar Production: Vinegar is produced by acetic acid fermentation through the action of acetic acid bacteria on ethanol, which is often derived from wine, cider, or fermented fruit juices.
• Kombucha: Kombucha is a fermented tea that involves a symbiotic colony of bacteria and yeast (SCOBY). In its secondary fermentation stage, acetic acid fermentation gives kombucha its characteristic sour taste.

4. Butyric Acid Fermentation Examples

• Butter and Cheese Flavoring: The characteristic flavors of certain butter and cheeses are partly due to butyric acid produced during fermentation.
• Bioplastics Production: Butyric acid produced from agricultural wastes through fermentation is used as a precursor for the production of biodegradable plastics.

5. Mixed Acid Fermentation Examples

• Industrial Solvents: Mixed acid fermentation by bacteria like Escherichia coli can produce solvents such as ethanol and acetone, which are used in various industrial applications.
• Pharmaceuticals: Some by-products of mixed acid fermentation are used in the manufacture of pharmaceuticals and as intermediates in chemical synthesis.

Ketone Bodies

Advantages of Fermentation

• Energy Production: It provides cells with a means of energy production in the absence of oxygen.
• Food Preservation: Fermentation helps in preserving food and enhancing its nutritional value.
• Industrial Applications: It is crucial in the production of alcohol, bread, yogurt, and many other products.
• Environmental Benefits: Fermentation is used in waste management and bioremediation by breaking down organic materials.