Question

How is cellular fermentation relevant to our society? What investigations are being made in this field? Give various examples from different research papers.

Answer 1

Fermentation is a cellular process that is anaerobic. It is the means used by certain cells to convert organic food into simpler compounds ,in which energy can be released from glucose even though oxygen is not available

TYPES:

Lactic Acid Fermentation - Pyruvic acid+NADH⟷lactic acid+NAD​+
​​Alcohol Fermentation - Pyruvic acid breaks down into acetaldehyde and CO2 is released. In the next step, ethanol is formed from acetaldehyde. NAD+ is also formed from NADH which is reused in glycolysis. Yeast and some bacteria carry out this type of fermentation. Enzyme pyruvic acid decarboxylase and alcohol dehydrogenase catalyse these reactions.

Acetic acid Fermentation -The first step is the formation of ethyl alcohol from sugar anaerobically using yeast.In the second step, ethyl alcohol is further oxidised to form acetic acid using acetobacter bacteria. Microbial oxidation of alcohol to acid is an aerobic process.

Butyric acid Fermentation - Sugar is first oxidised to pyruvate by the process of glycolysis and then pyruvate is further oxidised to form acetyl-CoA by the oxidoreductase enzyme system with the production of CO2 and H2. acetyl-CoA is further reduced to form butyric acid. This type of fermentation leads to a relatively higher yield of energy. 3 molecules of ATP are formed.

In society,fermentation is suitable for all kinds of environments. It is one of the oldest metabolic processes which is common to prokaryotes and eukaryotes.It is widely used in various industries.

Using suitable microorganisms and specified conditions different kinds of products are produced:-

Wine Beer Biofuels Yogurt Pickles Bread Sour foods containing lactic acid Certain antibiotics and vitamins

Fermentation can make food nutritious, digestible and flavoured. There are many benefits of consuming fermented food.

It improves digestion and helps to maintain intestinal bacteria It has an anti-cancer effect. Improves immune system Reduces lactose intolerance

Other than the food industry there are many other areas where the fermentation process is used. Methane is produced by fermentation in the sewage treatment plants and freshwater sediments.

FEW RECENT INVESTIGATIONS MADE THROUGH RESEARCHES:

BIOMASS BASED PRODUCTION : Agricultural crops that contain high amounts of sugar such as corn, sweet potatoes, and sugarcane are efficient materials for fermentation as well as starchy materials such as rice, wheat, barley, and oats. Other biomass sources that are suitable for producing bioethanol include lignocellulosic biomass such as forest residues, agricultural wastes, food processing wastes, energy crops, wood residues, sawdust, and paper mill residues.

Extractive Fermentation for the Production of Carboxylic Acids:In general, extractive fermentation allows continuous production and recovery of the desired fermentation product in one continuous step, significantly improving reactor productivity and final product concentration by reducing end-product inhibition

Production of Bioethanol From Sugarcane Bagasse:Bioethanol is regarded as a more environmentally friendly fuel than gasoline. Sugarcane bagasse (SCB) is a potentially renewable resource that may be used to produce bioethanol, which is one of the largest cellulosic agro-industrial by-products. Over the last decade many efforts have been made to achieve maximum prehydrolysis and sachharification efficiency to obtain higher yields of fermentable sugar and ethanol from SCB.

Selection of potential probiotic lactic acid bacteria from fermented vegetable by in vitro tests:study aims to evaluate the probiotic potential of lactic acid bacteria (LAB) isolated from fermented vegetable. Six isolates to be used as probiotic starters for the improvement of the traditional fermentation process and the production of newly added value functional foods.