Microbes in Production of Biogas Questions in English

(A) The production of biogas is a microbial process. The type of gas produced depends on the specific type of microbes present (e.g.,methanogens) and the nature of the organic substrate (waste) being decomposed by them. Different microbes break down different organic materials to produce gases like $CH_4$,$CO_2$,and $H_2S$.

(A) $Methanogens$ are a group of anaerobic bacteria that thrive in oxygen-deficient environments.
They are commonly found in the anaerobic sludge during sewage treatment and in the rumen (a part of the stomach) of cattle.
These bacteria break down cellulosic material and produce large amounts of methane $(CH_4)$,carbon dioxide $(CO_2)$,and hydrogen $(H_2)$,which are collectively known as biogas.

(D) Methanogens are a group of bacteria that produce methane $(CH_4)$ under anaerobic conditions.
They are commonly found in the rumen (a part of the stomach) of cattle,where they help in the breakdown of cellulose.
They are also present in the excreta (dung) of these cattle.
Furthermore,they are found in anaerobic sludge during sewage treatment,where they are utilized for biogas production.
Therefore,all the given options are correct.

(C) In a biogas plant,the concrete tank is a deep pit where bio-wastes are collected and a slurry of dung is fed.
According to the $NCERT$ textbook,the depth of this concrete tank is typically $10-15$ feet.
This tank is covered with a floating cover that keeps rising as gas is produced in the tank due to the microbial activity of methanogens.

(C) In a biogas plant,the anaerobic digestion of organic waste by methanogenic bacteria produces biogas,which is a mixture of gases including $CH_4$,$CO_2$,and $H_2S$.
As the bacteria break down the organic matter,the gas accumulates in the tank.
The floating cover (gas holder) is designed to rise as the volume of the produced gas increases.
Therefore,the upward movement of the floating cover indicates that biogas has been generated by the microbial activity.

(B) In India,the technology of biogas production was developed mainly due to the efforts of the Indian Agricultural Research Institute $(IARI)$ and the Khadi and Village Industries Commission $(KVIC)$.
These organizations played a pivotal role in promoting biogas plants in rural areas to provide a sustainable source of energy and organic fertilizer.

(C) Anaerobic bacteria,specifically methanogens (e.g.,$Methanobacterium$),act on cellulosic material during the process of anaerobic digestion.
This process is commonly observed in the rumen of cattle and in biogas plants.
The breakdown of cellulose by these bacteria under anaerobic conditions results in the production of a mixture of gases,primarily $CH_4$ (Methane),$CO_2$ (Carbon dioxide),and $H_2$ (Hydrogen).
Therefore,the correct combination of gases produced is Methane,Carbon dioxide,and Hydrogen.

(B) The given figure represents a typical biogas plant.
It consists of a concrete tank (digester) where bio-wastes are collected and a slurry of dung is fed.
$P$ represents gas,$Q$ represents the gas holder,$R$ represents the sludge,and $S$ represents the digester.

(C) In a standard biogas plant diagram,the component '$Q$' typically represents the 'Gas holder' (the floating cover where biogas collects),and the component '$S$' represents the 'Slurry' (the mixture of dung and water that undergoes anaerobic digestion). Therefore,'$Q$' is the Gas holder and '$S$' is the Slurry.

(A) The provided figure represents a typical biogas plant.
In this diagram:
- '$P$' represents the gas (biogas) being released from the gas holder.
- '$Q$' represents the gas holder.
- '$R$' represents the sludge (spent slurry) which is removed from the outlet.
- '$S$' represents the digester tank containing the slurry.
Therefore,'$R$' represents sludge and '$P$' represents gas.

(B) Biogas production is a result of the anaerobic activity of methanogens.
These microorganisms,such as $Methanobacterium$,grow anaerobically on cellulosic material.
They break down cellulose to produce large amounts of methane $(CH_{4})$,along with $CO_{2}$ and $H_{2}$.
Therefore,the correct statement is that methanogens act on cellulose and release biogas.
Thus,the correct option is $(B)$.

(A) Biogas is a mixture of gases produced by the microbial activity of methanogens.
Among these,methane $(CH_4)$ is the primary component.
Biogas typically contains approximately $50-70 \%$ methane,making it the predominant gas present.

(B) Methanogens are archaebacteria that live in anaerobic environments,such as the rumen of cattle,where they exist in a symbiotic relationship to help in the digestion of cellulose. This is a correct statement.
Methanogens are indeed used in the production of biogas (methane) from organic waste in biogas plants. This is also a correct statement.
However,the fact that they are used for biogas production is not the reason why they form symbiotic associations with eukaryotes. Therefore,the Reason is not the correct explanation of the Assertion.

(A) Biogas is a mixture of gases (containing predominantly $CH_4$) produced by the microbial activity. During the anaerobic digestion of organic waste like cow dung,methanogenic bacteria (e.g.,$Methanobacterium$) break down the biomass to produce biogas,which is rich in methane.

(A) Biogas,commonly known as gobar gas,is a methane-rich fuel gas produced by the anaerobic breakdown or digestion of biomass (mainly animal waste like cow dung) with the help of methanogenic bacteria.
It is primarily composed of methane $(50-70\%)$,$CO_{2}$ $(30-40\%)$,and traces of hydrogen,nitrogen,and $H_{2}S$.

(A) Biogas is a methane-rich fuel gas produced by the anaerobic breakdown or digestion of organic matter (cellulosic material) with the help of methanogenic bacteria.
Methanogens,such as $Methanobacterium$,are found in the anaerobic sludge during sewage treatment and in the rumen of cattle.
These bacteria produce a mixture of gases,primarily methane $(50-70\%)$,carbon dioxide $(30-40\%)$,and traces of other gases like hydrogen,hydrogen sulphide,and nitrogen.
Oxygen is not produced during this anaerobic process; in fact,it is inhibited by oxygen.
Therefore,the correct products are methane $(I)$ and carbon dioxide $(II)$.

(C) Methanogens are a group of archaebacteria that produce methane $(CH_{4})$ as a metabolic byproduct in hypoxic conditions.
They are commonly found in the following environments:
$(i)$ The rumen (a part of the stomach) of herbivorous cattle,where they help in the breakdown of cellulose.
$(ii)$ Anaerobic sludge produced during sewage treatment,where they play a crucial role in the production of biogas.
Therefore,statements $II$ and $IV$ are correct.

(D) Biogas or gobar gas is produced during the anaerobic fermentation of agricultural wastes.
Biogas is a mixture of gases (predominantly methane) produced by the microbial activity.
It is used as a fuel for heating,cooking,and lighting,and as a power source for irrigation.
It serves as an eco-friendly and pollution-free alternative to firewood,kerosene,dung cakes,electricity,and $LPG$.

(A) Methanogens,particularly $Methanobacterium$,are anaerobic bacteria that thrive in environments lacking oxygen.
Statement $I$ is correct because these bacteria are commonly found in the anaerobic sludge formed during sewage treatment.
Statement $II$ is correct because they are present in the rumen (a part of the stomach) of cattle,where they break down cellulosic material.
Statement $III$ is correct because by digesting cellulose,they help in the nutrition of cattle.
Therefore,all three statements are correct.

(B) Biogas $(A)$ is a methane-rich fuel gas produced by anaerobic $(B)$ breakdown of organic matter with the help of methanogenic $(C)$ bacteria,such as Methanobacterium. These bacteria grow anaerobically on cellulosic material to produce large amounts of methane,$CO_2$,and $H_2$.

(D) Methanogens produce methane,$CO_{2}$,and hydrogen.
Biogas is a methane-rich fuel gas produced by the anaerobic breakdown or digestion of biomass with the help of methanogenic bacteria.
Biogas is primarily composed of methane,carbon dioxide,and traces of hydrogen.

(C) Biogas or gobar gas generation has been taken up in India on a large scale.
The technology for biogas production from cow dung was developed in India largely due to the efforts of the Indian Agricultural Research Institute $(IARI)$ and the Khadi and Village Industries Commission $(KVIC)$.

(A) Biogas is a mixture of gases produced by the microbial activity of methanogens.
The major component of biogas is methane $(CH_{4})$,which is highly inflammable and constitutes about $50-68\%$ of the mixture.
Other gases present include carbon dioxide $(CO_{2})$ at $25-35\%$,hydrogen $(H_{2})$ at $1-7\%$,and small amounts of hydrogen sulphide $(H_{2}S)$.
Therefore,the correct mixture of inflammable gases is methane,$CO_{2}, H_{2}$ and $H_{2}S$.

(A) Biogas is pathogen-free because the process of anaerobic digestion inactivates pathogens and parasites. This process is highly effective in reducing the incidence of water-borne diseases by eliminating harmful microorganisms present in the organic waste.

(C) Biogas production occurs in three main stages:
$1$. Stage $I$: Complex organic polymers like proteins,fats,and carbohydrates (cellulose,hemicellulose) are broken down into soluble monomers by hydrolytic bacteria.
$2$. Stage $II$: These monomers are converted into organic acids (like acetic acid) by fermentative microbes $(A)$.
$3$. Stage $III$: Finally,methanogenic bacteria $(B)$ act on these organic acids to produce biogas,which consists mainly of methane $(CH_{4})$ and carbon dioxide $(CO_{2})$ $(C)$.
Therefore,$A$ represents fermentative microbes,$B$ represents methanogenic bacteria,and $C$ represents $CO_{2}$ and methane.

(C) In a typical biogas plant:
$1$. The input mixture of dung and water is fed into the digester through the inlet tank,which is labeled as $C$.
$2$. The gas holder (labeled as $B$) collects the biogas,which consists primarily of $CH_{4}$ and $CO_{2}$.
$3$. The spent slurry (sludge) is removed through the outlet tank,which is labeled as $A$.
Therefore,$A$ represents sludge,$B$ represents the gas holder containing $CH_{4} + CO_{2}$,and $C$ represents the inlet for dung $+$ water.
Matching these with the options,the correct sequence is $A-$Sludge,$B-CH_{4} + CO_{2}$,$C-$Dung $+$ water.

(C) Biogas is a mixture of gases produced by the microbial activity of methanogens on organic waste under anaerobic conditions.
Its primary composition includes Methane $(CH_4)$,Carbon dioxide $(CO_2)$,and Hydrogen $(H_2)$,along with trace amounts of other gases like Hydrogen sulphide $(H_2S)$.

(B) Based on the standard diagram of a biogas plant:
$A$ represents the output gas (biogas) being released.
$B$ represents the floating gas holder,which stores the gas produced by microbial activity.
$C$ represents the digester tank,where the slurry of dung and water undergoes anaerobic digestion by methanogens.
Therefore,the correct identification is $A-$Gas,$B-$Gas holder,and $C-$Digester.

(A) Methanogens are a group of anaerobic bacteria that produce methane $(CH_4)$ as a metabolic byproduct in anoxic conditions. These bacteria are commonly found in the anaerobic sludge during sewage treatment and in the rumen of cattle,where they help in the breakdown of cellulose. Due to their ability to produce methane,they are collectively referred to as methanogens and are essential for biogas production.

(B) The technology of biogas production was developed in India mainly due to the efforts of the Indian Agricultural Research Institute $(IARI)$ and the Khadi and Village Industries Commission $(KVIC)$.

(C) Biogas is a mixture of gases produced by the microbial activity and may be used as fuel.
Its composition is as follows:
$CH_4$ (Methane): $50-70\%$
$CO_2$ (Carbon dioxide): $30-40\%$
$H_2, H_2S$ and other trace gases: $10\%$
Therefore, the correct option is $C$.

(B) The production of biogas occurs in three stages: solubilization,acidogenesis,and methanogenesis. The initial breakdown of complex organic matter (like cellulose) into simpler monomers is carried out by decomposers (cellulolytic bacteria). Methanogens are involved in the final stage of biogas production,where they convert organic acids into methane $(CH_4)$. Therefore,the first step is initiated by decomposers.

(B) The statement in option $B$ is incorrect. In a biogas plant,a floating cover is placed over the slurry,which keeps on rising as the gas is produced in the tank due to microbial activity,not as it is consumed.

(C) The chief component of biogas is methane $(CH_4)$,which typically constitutes $50\% - 70\%$ of the gas.
In India,the technology for biogas plants was developed by the Indian Agricultural Research Institute $(IARI)$ and the Khadi and Village Industries Commission $(KVIC)$.
Therefore,these plants are based on indigenous (Indian) technology,not foreign technology.
Thus,the Assertion is correct,but the Reason is incorrect.

(B) Methanogens are archaebacteria that thrive in anaerobic environments like the rumen of cattle and marshy areas.
They are responsible for the production of methane (biogas) from organic waste.
They contribute significantly to the environment by producing approximately $65 \%$ of the total atmospheric methane.

(A) During the sewage treatment process,specifically in the anaerobic sludge digesters,anaerobic bacteria digest the organic matter present in the sludge.
This process produces a mixture of gases,which is known as biogas.
Biogas primarily consists of methane $(CH_4)$,carbon dioxide $(CO_2)$,and hydrogen sulfide $(H_2S)$.
Therefore,the correct composition of gases produced during this process is $CH_4, CO_2,$ and $H_2S$.

(C) Methanogens,such as $Methanobacterium$,are anaerobic bacteria that grow in anaerobic conditions.
These bacteria are found in the rumen of cattle and in sewage treatment plants.
In a biogas plant,these bacteria break down cellulosic material present in the dung (gobar) of cattle.
During this process,they produce a mixture of gases,primarily $CH_4$ (methane),$CO_2$ (carbon dioxide),and $H_2$ (hydrogen).
Therefore,the correct composition of gases produced is $CH_4, CO_2,$ and $H_2$.

(B) In a typical biogas plant diagram:
- $P$ represents the gas outlet pipe.
- $Q$ represents the floating gas holder (gas drum) that stores the produced biogas.
- $R$ represents the outlet for spent slurry (fertilizer).
- $S$ represents the digester tank where anaerobic digestion occurs.
Therefore,$Q$ is the gas holder.

(C) In India,the technology for biogas production was developed mainly by the efforts of the Indian Agricultural Research Institute $(IARI)$ and the Khadi and Village Industries Commission $(KVIC)$.
Both these organizations played a crucial role in promoting and implementing biogas plants in rural areas to provide a sustainable source of energy and organic fertilizer.

(D) Methanogens are a group of anaerobic bacteria that produce methane $(CH_4)$ as a metabolic byproduct in anoxic conditions.
They are commonly found in the rumen (a part of the stomach) of cattle and other ruminant animals,where they help in the breakdown of cellulose.
They also grow anaerobically on cellulosic material in anaerobic sludge digesters to produce biogas.
Therefore,option $D$ is the correct statement.

(B) Biogas is a mixture of gases produced by the microbial activity of methanogens (anaerobic bacteria) on organic waste.
The primary components of biogas are methane $(CH_4)$,carbon dioxide $(CO_2)$,and hydrogen $(H_2)$.
Methane is the major combustible component,while $CO_2$ and $H_2$ are present in smaller quantities.
Therefore,the correct composition is $CH_4, CO_2, H_2$.

(D) Biogas is a mixture of gases produced by the microbial activity of methanogens (e.g.,Methanobacterium) during the anaerobic breakdown of organic waste.
The primary component of biogas is methane $(CH_4)$,which is flammable.
Other gases present in biogas include carbon dioxide $(CO_2)$,hydrogen $(H_2)$,nitrogen $(N_2)$,and trace amounts of hydrogen sulfide $(H_2S)$.
Therefore,the correct composition is $CH_4, CO_2, H_2, N_2, H_2S$.

(A) Gobar gas plant,also known as a biogas plant,utilizes anaerobic bacteria to break down organic waste (like cattle dung).
These bacteria are collectively known as Methanogens.
Methanogens,such as $Methanobacterium$,grow anaerobically on cellulosic material and produce large amounts of methane $(CH_4)$,carbon dioxide $(CO_2)$,and hydrogen $(H_2)$.
These gases together constitute biogas.

(C) Methanogens,such as $Methanococcus$,are anaerobic bacteria that thrive in oxygen-deficient environments.
They perform methanogenesis,a metabolic process where they convert substrates like acetate,$H_2$,and $CO_2$ into methane $(CH_4)$,$CO_2$,and $H_2O$ as metabolic byproducts.

(A) The process of biogas production occurs in three main stages:
$1$. Solubilization (Hydrolysis): Complex organic polymers like carbohydrates,proteins,and fats are broken down into their simpler monomers like simple sugars,amino acids,and fatty acids by extracellular enzymes.
$2$. Acidogenesis: These simple monomers are further converted into volatile fatty acids like acetic acid,formic acid,and alcohols.
$3$. Methanogenesis: Finally,acetic acid or formic acid is converted into methane $(CH_4)$,$CO_2$,and $H_2O$ by methanogenic bacteria.
Therefore,the correct reaction for solubilization is that carbohydrates and proteins are converted into simple sugars and amino acids respectively.

(C) The process of anaerobic digestion in biogas production occurs in three main stages:
$1$. Hydrolysis: Complex organic polymers like carbohydrates,proteins,and fats are broken down into simpler monomers like sugars,amino acids,and fatty acids by extracellular enzymes.
$2$. Acidogenesis: These monomers are further converted into volatile fatty acids (like acetic acid),alcohols,and gases (like $CO_2$ and $H_2$) by acidogenic bacteria.
$3$. Methanogenesis: Finally,methanogenic bacteria (methanogens) convert these products into methane $(CH_4)$ and carbon dioxide $(CO_2)$.
Therefore,the correct sequence is Hydrolysis $\longrightarrow$ Acidogenesis $\longrightarrow$ Methanogenesis.

(A) Cattle dung,also known as cow dung,is used as a substrate in biogas plants because it contains a high concentration of cellulose.
Cellulose is a complex carbohydrate found in the cell walls of plants,which cattle consume as part of their diet.
During the process of anaerobic digestion,methanogenic bacteria (methanogens) break down this cellulose into simpler compounds,ultimately producing methane $(CH_4)$,which is the primary component of biogas.

(A) Biogas is a clean,renewable,and eco-friendly source of energy.
It is produced by the anaerobic breakdown of organic matter.
Statement $i$ is correct as it is a cost-effective and safe fuel.
Statement $ii$ is correct as it is widely used for cooking and lighting.
Statement $iii$ is correct as it can be transported through pipelines.
Statement $iv$ is incorrect because biogas is a clean fuel that does not cause significant pollution compared to fossil fuels; it actually helps in waste management and reduces greenhouse gas emissions.

(C) Biogas production involves the anaerobic breakdown of organic matter (slurry) by microorganisms. The process occurs in three main stages:
$1$. $Hydrolysis$: Complex organic polymers like carbohydrates,proteins,and fats are broken down into simpler monomers like sugars,amino acids,and fatty acids.
$2$. $Acidogenesis$: These monomers are further converted into volatile fatty acids,alcohols,and gases like $CO_2$ and $H_2$ by acidogenic bacteria.
$3$. $Methanogenesis$: Finally,methanogenic bacteria convert these products into methane $(CH_4)$ and $CO_2$.
$Photolysis$ is the decomposition of molecules by light energy,which does not occur in the dark,anaerobic environment of a biogas digester.

(A) In a biogas plant,the anaerobic digestion process occurs in three main stages: $1.$ Solubilization (Hydrolysis),$2.$ Acidogenesis,and $3.$ Methanogenesis.
During the acidogenesis stage,acidogenic bacteria (also known as acid-forming bacteria) break down the monomers produced during the hydrolysis phase (such as sugars and amino acids) into organic acids (like acetic acid,propionic acid,and butyric acid),alcohols,$H_2$,and $CO_2$.
Therefore,the primary role of acidogenic bacteria is to convert monomers into organic acids.