Microorganisms go for fermentation process when they lack Electron transport chain (ETC) i,.e they are strict anaerobic microorganisms or the working of ETC get repressed (in anaerobic condition). The major and absolute aim of any living organism, be it human, plants, animals or microorganisms to produce energy in the form of ATP in order to survive. There are many ways to produce ATP. Major one is through oxidative phosphorylation in which oxygen is used as final acceptor of electron during the process of ETC. Hence, such system will only work in presence of aerobic environment. But what about those microorganisms who are anerobes or, if some reason no oxygen is present in environment? In order to survive, these organisms evolve themselves in such a way that even if ETC can\'t work due to absence of oxygen they can still produce ATP by oxidizing NADH to NAD+. As reduced NAD+ being utlized during glycolysis and hence, ATP is produced. Therefore, if I summarise fermentation significance 1. It is a survival tool for microorganisms growth in absence of oxygen (anaerobic environment) or for anaerobic bacteria 2.NADH is oxidized to NAD+ so that reduced NAD+ can be re-utilized during the process of glycolysis 3. Since, no oxygen present therefore the final electron acceptor is often either pyruvate or a pyruvate derivative. Thus substrate is partialy oxidized and hence, ATP is formed by substrate level phospohorylation. Members of the family Enterobacteriaceae have the ability to metabolize pyruvate into numerous products by utilizing several pathways simultaneously and hence resulted in excretion of various mixture of acids (acetic, lactic, succinic) and ethanols. This is known as the mixed acid fermentation. Solution Microorganisms go for fermentation process when they lack Electron transport chain (ETC) i,.e they are strict anaerobic microorganisms or the working of ETC get repressed (in anaerobic condition). The major and absolute aim of any living organism, be it human, plants, animals or microorganisms to produce energy in the form of ATP in order to survive. There are many ways to produce ATP. Major one is through oxidative phosphorylation in which oxygen is used as final acceptor of electron during the process of ETC. Hence, such system will only work in presence of aerobic environment. But what about those microorganisms who are anerobes or, if some reason no oxygen is present in environment? In order to survive, these organisms evolve themselves in such a way that even if ETC can\'t work due to absence of oxygen they can still produce ATP by oxidizing NADH to NAD+. As reduced NAD+ being utlized during glycolysis and hence, ATP is produced. Therefore, if I summarise fermentation significance 1. It is a survival tool for microorganisms growth in absence of oxygen (anaerobic environment) or for anaerobic bacteria 2.NADH is oxidized to NAD+ so that reduced NAD+ can be re-utilized during the process of glycolysis 3. Since, no oxygen present th.

1. Microorganisms go for fermentation process when they lack Electron transport chain (ETC) i,.e
they are strict anaerobic microorganisms or the working of ETC get repressed (in anaerobic
condition).
The major and absolute aim of any living organism, be it human, plants, animals or
microorganisms to produce energy in the form of ATP in order to survive. There are many ways
to produce ATP. Major one is through oxidative phosphorylation in which oxygen is used as
final acceptor of electron during the process of ETC. Hence, such system will only work in
presence of aerobic environment. But what about those microorganisms who are anerobes or, if
some reason no oxygen is present in environment? In order to survive, these organisms evolve
themselves in such a way that even if ETC can't work due to absence of oxygen they can still
produce ATP by oxidizing NADH to NAD+. As reduced NAD+ being utlized during glycolysis
and hence, ATP is produced.
Therefore, if I summarise fermentation significance
1. It is a survival tool for microorganisms growth in absence of oxygen (anaerobic environment)
or for anaerobic bacteria
2.NADH is oxidized to NAD+ so that reduced NAD+ can be re-utilized during the process of
glycolysis
3. Since, no oxygen present therefore the final electron acceptor is often either pyruvate or a
pyruvate derivative. Thus substrate is partialy oxidized and hence, ATP is formed by substrate
level phospohorylation.
Members of the family Enterobacteriaceae have the ability to metabolize pyruvate into numerous
products by utilizing several pathways simultaneously and hence resulted in excretion of various
mixture of acids (acetic, lactic, succinic) and ethanols. This is known as the mixed acid
fermentation.
Solution
Microorganisms go for fermentation process when they lack Electron transport chain (ETC) i,.e
they are strict anaerobic microorganisms or the working of ETC get repressed (in anaerobic
condition).
The major and absolute aim of any living organism, be it human, plants, animals or
microorganisms to produce energy in the form of ATP in order to survive. There are many ways
to produce ATP. Major one is through oxidative phosphorylation in which oxygen is used as
final acceptor of electron during the process of ETC. Hence, such system will only work in
presence of aerobic environment. But what about those microorganisms who are anerobes or, if

2. some reason no oxygen is present in environment? In order to survive, these organisms evolve
themselves in such a way that even if ETC can't work due to absence of oxygen they can still
produce ATP by oxidizing NADH to NAD+. As reduced NAD+ being utlized during glycolysis
and hence, ATP is produced.
Therefore, if I summarise fermentation significance
1. It is a survival tool for microorganisms growth in absence of oxygen (anaerobic environment)
or for anaerobic bacteria
2.NADH is oxidized to NAD+ so that reduced NAD+ can be re-utilized during the process of
glycolysis
3. Since, no oxygen present therefore the final electron acceptor is often either pyruvate or a
pyruvate derivative. Thus substrate is partialy oxidized and hence, ATP is formed by substrate
level phospohorylation.
Members of the family Enterobacteriaceae have the ability to metabolize pyruvate into numerous
products by utilizing several pathways simultaneously and hence resulted in excretion of various
mixture of acids (acetic, lactic, succinic) and ethanols. This is known as the mixed acid
fermentation.