Fermentation is an enzyme-catalyzed process that converts carbohydrates like starch and sugar into acids, alcohols, and gases, releasing energy. It occurs in the gastrointestinal tracts of animals through microbes like bacteria and yeast. Lactic acid fermentation produces lactic acid as bacteria like Lactobacillus ferment sugars anaerobically. Alcoholic fermentation by yeast converts sugar into ethanol and carbon dioxide to produce beverages. Fermentation has industrial uses and was an early form of biotechnology.
2. What is fermentation ?
Fermentation is an enzyme catalyzed , metabolic process. And it converts starch or sugar in to alcohol or
acids and releasing energy.
Fermentation is the enzymatic decomposition and food stuffs particularly carbohydrates by microbes.
Fermentation takes place throughout the gastro intestinal tract of all animals.
Large intestine is quantitatively the most important site of fermentation.
In carnivores (dogs , cats), omnivores (humans) fermentation generates rather few calories.
But in herbivores fermentation is a way of life.
Anaerobes produce energy by reactions called fermentation.
Which use organic compounds as electron donors and acceptors.
In animals fermentation contribute 2 processes
1. Digestion of carbohydrates not digested in the small intestine.
2. Synthesis of Vitamin-K and Vitamin- B.
3. In fermentation mostly the end product is cellulose. But sometimes
carbohydrates are volatile fatty acids, lactic acids, methane, hydrogen
and CO2.
Fermentation is thus the major source of intestinal gas.
Volatile fatty acids generated from fermentation can be absorbed by
diffusion in the colon.
Vit-K synthesis by colonic bacteria. It is valuable source dietary
source.
Formation of vit –B complex by fermentation. This whole process
takes place in large int3stine and useful for many animals. And it is
not absorbed in large intestine nut present in feaces .
4. HISTORY OF FERMENTATION
Mankind is practicizing fermentation since pre-historic times. This
useful conventional technology has risen by accident.
During pre-historic times, women made learned the art of kaffir
beer from their husband before they get marry.
The term fermentation is derived from the Latin verb ‘fervere’, to
boil, which describes the appearance of the action of yeast on
extracts of fruits or malted grain during the production of alcoholic
beverages.
Sorghum grains or millet are germinated, sundried ground and
mixed with sorghum, millet or maize flours and water, and then
cooked, cooled and fermented by the residual yeast and the dregs in
the containers.
The use of fermentation starts might very well have its origins in
the process of Euchok , the daughter of the legendary king of Woo
of 4000 BC, known as the Goddess of rice wine in Chinese culture.
5. Understanding of scientific procedure of fermentation microbiology began in 1850s, after Louis
Pasteur, who has succeed in producing two forms of amyls alcohol by fermentation.
Between 1900 and 1930, ethyl alcohol and butyl alcohol are the most important industrial
fermentations in the word. But by the 1960s, chemical synthesis of alcohol and other solvents were
less expensive and interest in fermentations diminished.
It is often mentioned that today’s modern biotechnology originated from the alcohol fermentation of
primitive peoples.
Nowadays, the development of genetic engineering has made it possible to use the process of
fermentation for the production of many compounds including vaccines, antibiotics and enzymes
and also for biological conversion of many substances.
6. LOUIS PASTEUR AND
FERMENTATION
First fermentation study was done by louis Pasteur at 19th century.
He describe fermentation is the process that produces alcoholic beverages.
For cell fermentation is a way of getting energy without using oxygen.
For animal or microbial cell obtained energy through glycolysis (EMP
Pathway).
In glycolysis splitting a sugar molecule and removing electrons from the
molecule.
Electrons are then passed to an organic molecule such as pyruvic acid.
It result in the formation of waste product and excrete from cell.
Waste products formed in this way include ethyl alcohol, butyl alcohol, lactic
acid, acetone.
7. FERMENTATION IN HUMAN LIFE
Food spoiled by microbial fermentation
Food made by microbial fermentation
Muscle cells use microbial fermentation to provide quick response.
Microbial fermentation gives basic food.
8. LACTIC ACID FERMENTATION
What is Lactic Acid Fermentation?
Lactic acid fermentation is a type of anaerobic respiration (or fermentation) that breaks down sugars to
produce energy in the form of ATP.
It is called anaerobic because it occurs in the absence of oxygen.
Lactic acid is generated as a byproduct of this reaction, which is what gives this type of fermentation its name.
One well-known example of lactic acid fermentation occurs during the production of yogurt
by Lactobacillus bacteria.
It is the lactic acid generated during this process that gives the yogurt a sour flavor.
Where Does Lactic Acid Fermentation Occur?
The lactic acid fermentation occurs in certain animal cells and bacterial organisms.
In animal cells, aerobic respiration is generally preferred - this process doesn't involve lactic acid fermentation.
9. However, in conditions where the oxygen supply is insufficient - primarily in muscle tissues, during periods
of strenuous exercise - cells must undergo anaerobic respiration in order to adequately meet the demand for
energy.
This process of anaerobic respiration produces lactic acid as a byproduct, which accumulates in the muscle
tissues.
The increased acidity is responsible for the burning sensation and weakness you feel in your muscles during
exercise, and this is believed to help prevent you from overworking your muscles.
Contrary to popular opinion, however, lactic acid is not the cause of delayed-onset muscle soreness (i.e. the
soreness you might feel the day after an intense workout.)
After the muscle activity is over, lactic acid is removed from the muscle tissue through the bloodstream.
It is then sent to the liver, where it undergoes chemical reactions to form pyruvic acid, which is used to
produce additional energy as ATP.
Apart from muscle tissue, this process also occurs in red blood cells, because they lack mitochondria and
thus cannot generate energy aerobically.
10. In bacterial organisms, lactic acid fermentation serves multiple functions.
Bacteria that carry out lactic acid fermentation are commonly referred to as Lactic Acid
Bacteria (LABs.)
While fermentation is crucial in allowing LABs to generate energy in anaerobic conditions, it
also helps them reduce the pH of their environment through the synthesis of lactic acid.
The lowered pH helps make their environment unsuitable for most other microorganisms and
thus reduces the competition faced by the LABs.
While some LABs are strictly anaerobic, others can switch between the two processes
depending on the availability of oxygen.
11. Lactic Acid Fermentation Products and Equation
The commonly used equation for Lactic acid Fermentation is:
Glucose + ADP + NADH -> C3H6O3 (Lactic Acid) + ATP + NAD+
While this equation highlights the lactic acid fermentation reactants and final products,
the process actually occurs in two steps.
1. The first process is called glycolysis (which is also a part of the aerobic respiration pathway.) Glycolysis
involves the conversion of glucose into 2 molecules of pyruvic acid, creating 2 ATP and 2NADH (from ADP and
NAD+) in the process. Because glycolysis does not require oxygen, it is considered an anaerobic process.
2. In the next step, each molecule of pyruvic acid is converted into lactic acid. As a byproduct, 4 NAD+ is
generated, 2 of which go back to continue the glycolysis pathway.
This pathway of lactic acid fermentation is also called the homolactic pathway.
Through this process, glucose is broken down to generate energy and lactic acid.
This pathway is most commonly employed by the lactic acid bacteria Pediococcus and Streptococcus, as well as
some species of Lactobacilli.
Apart from glucose, other sugars such as lactose and maltose can also be used in lactic acid fermentation.
12. FERMENTATION AND BIOTECHNOLOGY
The following points highlight the eight main types of fermentations.
The types are:-
1. Batch Fermentation
2. Continuous Fermentation
3. Fed Batch Fermentation
4. Anaerobic Fermentation
5. Aerobic Fermentation
6. Surface Fermentations
7. Submerged Fermentations
8. State Fermentation.
13.
14. ALCOHOLIC FERMENTATION
Alcoholic fermentation is a process by which sugar is
converted into ethyl alcohol and CO2 by some
bacteria and yeast.
First, sugar is converted into pyruvic acid, which is
then converted into ethanol and carbon dioxide by
pyruvate decarboxylase and alcohol dehydrogenase.
This process is utilised in the production of alcoholic
beverages and bread.