Extracting fermentable sugars from grains are critical to the success of yeast fermentation, and production of alcohol could not occur without the work of amylase enzymes to break down starch into simple sugars that are usable by yeast. Also, many steps of the metabolic pathways used by yeast are enzyme-dependent.
Fermentation: Definition
Fermentation is an enzyme-catalyzed metabolic process by which organisms convert starch or sugars into alcohol or an acid that anaerobically releases energy. The science of fermentation is called "zymology".
Fermentation is an anaerobic biochemical process. In fermentation, the first process is the same as cellular respiration, which is the formation of pyruvic acid through glycolysis
where 2 net ATP molecules are synthesized. In the next step pyruvate is reduced to lactic acid, ethanol or other products.
NAD+ is formed here and reused in the glycolysis process.
Based on the end product formed, fermentation can be classified as follows:
1. Lactic acid fermentation
Lactic acid is formed in
from pyruvate, which is formed during glycolysis. NAD+ is generated from NADH. The enzyme lactate dehydrogenase catalyses this reaction.
Lactobacillus bacteria produce milk curd through this type of fermentation. During intense training, when the supply of oxygen is insufficient, the muscles gain energy by producing lactic acid, which accumulates in the cells and causes fatigue.
2. Alcohol fermentation
It is used in the industrial production of wine, beer, biofuels, etc. The end product is alcohol and CO 2.
Puruvic acid decomposes to acetaldehyde releasing CO2. In the next step, acetaldehyde is converted into ethanol. NAD+ is also formed from NADH, which is used in glycolysis. Yeast and some bacteria perform this type of fermentation. The enzymes pyruvic acid decarboxylase and alcohol dehydrogenase catalyze these reactions.
. Acetic acid fermentation
Vinegar is produced using this process. This is a two-step process.
The first step is the anaerobic formation of ethyl alcohol from sugar using yeast.
In the second step, ethyl alcohol is further oxidized to acetic acid with Acetobacter bacteria.
The microbial oxidation of alcohol to acid is an aerobic process.
4. Butyric acid fermentation
This type of fermentation is characteristic of obligate anaerobic bacteria of the Clostridium genus. This occurs in the roasting of jute fibers, rancid butter, tobacco processing, and leather tanning. Butyric acid is formed in the human large intestine as a product of fiber fermentation.
It is an important source of energy for the colorectal epithelium.
The The fermentation is suitable for all types of environments. It is one of the oldest metabolic processes common to prokaryotes and eukaryotes. Fermentation is widely used in various industries.
Using appropriate microorganisms and specific conditions,
different types of fermentation products are formed, namely:-
Fermentation can make food nutritious, digestible and tasty.
There are many benefits of eating fermented foods.
Fermentation is a metabolic process that releases energy from sugar or other substrates through various enzymatic actions. It is a kind of anaerobic biochemical process.
This is where microorganisms such as fungi and bacteria are intentionally used for fermentation to produce end products that are useful to humans . .
Common chemicals such as citric acid, acetic acid and ethanol are produced by industrial fermentation.
Depending on the product end formed, fermentation can be divided into four types namely lactic acid fermentation, alcohol fermentation, acetic acid fermentation and butyric acid fermentation.