Microbes in Production of Biogas Questions in English

(A) Compost manure is formed by the decomposition of organic matter such as rotted vegetable matter,garbage,sewage sludge,and animal refuse. During the decomposition process,these materials are often enriched with a small amount of chemical fertilizers to enhance the nutrient content.

(A) Cow dung is primarily and most appropriately used as manure.
Manure is a semi-decayed organic matter that is added to the soil to maintain its fertility,crumb structure,aeration,and water-holding capacity.
It is derived from animal waste,farm refuse,and decomposed plant matter.

(B) Methanogens are a group of archaebacteria that are strictly anaerobic.
They are found in marshy areas and in the rumen of ruminant animals like cows and buffaloes.
These bacteria are responsible for the production of methane (biogas) from the dung of these animals.
Therefore,the correct option is $B$.

(C) Biogas is a mixture of gases (predominantly $CH_4$) produced by the microbial activity of methanogens.
Methanogens,such as $Methanobacterium$,are anaerobic bacteria that grow on cellulosic material present in the dung of ruminant animals.
These bacteria break down the organic matter in the dung under anaerobic conditions to produce biogas,which includes methane,$CO_2$,and $H_2$.

(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 rumen of cattle and in anaerobic sludge or sewage treatment plants.
In a biogas plant,methanogens break down cellulosic material and other organic waste to produce biogas,which is primarily composed of methane.
Therefore,methanogens are the correct answer.

(C) Biogas is a mixture of gases produced by the microbial activity of methanogens (e.g.,Methanobacterium) on cellulosic material during anaerobic digestion.
It primarily consists of $CH_4$ (Methane),which typically accounts for $50-70\%$ of the total volume.
Other components include $CO_2$ (Carbon dioxide),$H_2$ (Hydrogen),and traces of $H_2S$ (Hydrogen sulfide).
Therefore,the major component is Methane.

(C) In India, the technology for biogas production was developed mainly by the Indian Agricultural Research Institute $(IARI)$ and the Khadi and Village Industries Commission $(KVIC)$.
Biogas plants are often set up in rural areas where cattle dung is readily available.
Apart from cattle dung, the use of water hyacinth $(Eichhornia \text{ } crassipes)$ is also recommended for biogas production because it grows rapidly in water bodies and can be harvested and processed to produce methane-rich biogas.

(C) Brazil is the world leader in the use of ethanol (alcohol) as a biofuel for vehicles. The country has implemented a successful program where a significant portion of its vehicle fleet runs on ethanol derived from sugarcane,or on a blend of gasoline and ethanol. This initiative has been instrumental in reducing the country's dependence on fossil fuels.

(B) Biogas production involves the anaerobic breakdown of organic matter by methanogenic bacteria.
Cellulose is a complex polysaccharide and a major component of plant cell walls.
Because cellulose is difficult to break down,it acts as the rate-limiting factor in the anaerobic digestion process for biogas production.
Therefore,the correct option is $B$.

(C) The production of biogas by methanogenic bacteria is a $3$-stage process:
$1$. Solubilization: Complex organic polymers like cellulose and proteins are broken down into simpler monomers like sugars and amino acids by extracellular enzymes.
$2$. Acidogenesis: The monomers are converted into organic acids (like acetic acid) and $CO_2$ by acid-forming bacteria.
$3$. Methanogenesis: Methanogenic bacteria (e.g.,$Methanobacterium$) convert these organic acids into methane $(CH_4)$ and $CO_2$ under anaerobic conditions.

(D) Biogas is a mixture of gases produced by the microbial activity of methanogens,which are anaerobic bacteria that grow on cellulosic material.
Biogas primarily consists of $CH_4$ (Methane),which typically accounts for $50-70\%$ of the total composition.
Other gases present in smaller quantities include $CO_2$ (Carbon dioxide),$H_2$ (Hydrogen),$N_2$ (Nitrogen),and $H_2S$ (Hydrogen sulfide).
Therefore,the highest amount of gas present in biogas is Methane.

(A) Biogas is a mixture of gases produced by the microbial activity of methanogens (e.g.,Methanobacterium) during the anaerobic breakdown of organic waste.
It primarily consists of Methane $(CH_4)$ and Carbon dioxide $(CO_2)$,along with trace amounts of other gases like Hydrogen $(H_2)$,Nitrogen $(N_2)$,and Hydrogen sulfide $(H_2S)$.
Therefore,the correct composition is $CH_4 + CO_2$.

(C) In a biogas plant,the anaerobic decomposition of organic matter,such as cow dung,is carried out by a group of bacteria known as methanogens.
These bacteria,specifically $Methanobacterium$,grow anaerobically on cellulosic material present in cow dung.
As a result of this metabolic process,they produce large amounts of methane $(CH_4)$,carbon dioxide $(CO_2)$,and hydrogen $(H_2)$,which collectively constitute biogas.

(D) Biogas is produced by the anaerobic breakdown of organic matter by methanogens.
It is beneficial because:
$1$. It is a highly efficient and renewable source of energy.
$2$. The spent slurry left after biogas production is rich in nutrients and serves as an excellent organic fertilizer.
$3$. The process of anaerobic digestion kills many pathogens present in waste,thereby preventing the spread of diseases.
Therefore,all the given options are correct.

(B) Biogas is a mixture of gases produced by the microbial activity of methanogens (e.g.,Methanobacterium) during the anaerobic breakdown of organic matter.
It primarily consists of Methane $(CH_4)$,Carbon dioxide $(CO_2)$,and Hydrogen $(H_2)$.
Therefore,the correct composition is $CH_4, CO_2, H_2$.

(A) In a gobar gas plant,anaerobic bacteria,specifically $Methanogens$ (e.g.,$Methanobacterium$),are used.
These bacteria grow anaerobically on cellulosic material present in cow dung (gobar).
They produce large amounts of methane $(CH_4)$,carbon dioxide $(CO_2)$,and hydrogen $(H_2)$,which collectively constitute biogas.

(C) The technology for biogas production in India 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 and implementing biogas plants in rural areas to provide a sustainable source of energy and organic fertilizer.

(D) Biogas is a mixture of gases (containing predominantly methane) produced by the microbial activity of methanogens on organic waste.
During anaerobic fermentation,methanogens (like $Methanobacterium$) break down cellulosic material and other organic matter.
The composition of biogas typically includes $CH_4$ (methane),$CO_2$ (carbon dioxide),and trace amounts of $H_2$ (hydrogen),$H_2S$ (hydrogen sulfide),and $N_2$ (nitrogen).
Therefore,all the listed components are present in biogas.

(D) Biogas is a mixture of gases (containing predominantly $CH_4$) produced by the microbial activity. The composition of biogas depends on the type of organic waste used as a substrate and the specific type of microbes (methanogens) involved in the anaerobic digestion process. Therefore,both the type of microbes and the type of organic waste determine the nature of the gas produced.

(B) Biogas is a mixture of gases produced by the microbial activity of methanogens (e.g.,$Methanobacterium$) during the anaerobic breakdown of organic matter. The primary components of biogas are methane $(CH_4)$,carbon dioxide $(CO_2)$,and hydrogen $(H_2)$. Methane is the major combustible component,while carbon dioxide and hydrogen are present in smaller quantities.

(B) Biogas production involves the anaerobic breakdown of organic matter by methanogenic bacteria.
Organic waste typically contains complex polymers like cellulose,hemicellulose,and lignin.
While cellulose and hemicellulose are polysaccharides that can be broken down by microbial enzymes during anaerobic digestion,lignin is a complex phenolic polymer that is highly resistant to microbial degradation under anaerobic conditions.
Therefore,lignin remains largely undegraded in the biogas plant.

(D) During the secondary treatment of sewage,anaerobic bacteria digest the organic matter present in the sludge. This process is known as anaerobic digestion. During this process,anaerobic bacteria produce a mixture of gases,primarily methane $(CH_4)$,hydrogen sulfide $(H_2S)$,and carbon dioxide $(CO_2)$. Methane is commonly known as marsh gas. Therefore,the correct answer is marsh gas.

(D) Hydrogen $(H_2)$ is considered a clean and efficient energy fuel. It releases a large amount of energy upon combustion,producing only water $(H_2O)$ as a byproduct,which makes it environmentally friendly. In the context of microbes,hydrogen gas is also produced during the anaerobic digestion of organic waste by methanogenic bacteria in biogas plants.

(D) Ethanol $(C_2H_5OH)$ is widely used as a biofuel or as an additive in gasoline to power vehicles.
It is produced through the fermentation of sugars by microbes like yeast $(Saccharomyces \ cerevisiae)$.
Ethanol is considered a cleaner-burning fuel compared to traditional fossil fuels,helping to reduce greenhouse gas emissions.

(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 (a part of the stomach) of cattle.
In the rumen,these bacteria help in the breakdown of cellulose,which is a major component of the food eaten by cattle,and produce large amounts of methane along with $CO_2$ and $H_2$.

(D) The rumen is the first stomach compartment of ruminant animals like cattle.
In the rumen,a large population of bacteria called $Methanogens$ is present.
These bacteria are anaerobic and help in the breakdown of cellulose,which is a major component of the food (grass/fodder) eaten by cattle.
As a byproduct of this fermentation process,$Methanogens$ produce large amounts of methane $(CH_4)$,which is why they are also involved in biogas production.

(A) Biogas is a mixture of gases produced by the microbial activity of methanogens (anaerobic bacteria) on organic waste.
The primary components of biogas are:
$1$. Methane $(CH_4)$: The main combustible component.
$2$. Carbon dioxide $(CO_2)$: Produced as a byproduct.
$3$. Hydrogen sulfide $(H_2S)$: Present in small quantities.
Therefore,the correct combination is $(i), (ii),$ and $(iii)$.

(C) Biogas is a mixture of gases produced by the microbial activity of methanogens on organic waste. The primary components of biogas are $CH_4$ (Methane),$CO_2$ (Carbon dioxide),and traces of $H_2S$ (Hydrogen sulfide),$H_2$ (Hydrogen),and $N_2$ (Nitrogen). Carbon monoxide $(CO)$ is not a typical component of biogas. Therefore,Carbon monoxide is the odd one out.

(C) In $STPs$ (Sewage Treatment Plants),the primary effluent is passed into large aeration tanks where it is mechanically agitated and air is pumped into it. This allows vigorous growth of aerobic microbes into flocs. After this,the effluent is passed into a settling tank where the bacterial flocs are allowed to sediment. This sediment is called activated sludge. $A$ small part of the activated sludge is pumped back into the aeration tank,and the remaining major part is pumped into large tanks called anaerobic sludge digesters. In these digesters,other kinds of bacteria,which grow anaerobically,digest the bacteria and the fungi in the sludge. During this digestion,bacteria produce a mixture of gases such as methane,hydrogen sulphide,and carbon dioxide,which form biogas.

(D) Biogas is a mixture of gases (containing predominantly $CH_4$) produced by the microbial activity of methanogens.
These methanogens grow anaerobically on cellulosic material.
The specific composition of the biogas produced depends on the type of substrate (organic waste) being digested and the specific microbial community (bacteria) present in the digester.
Therefore,both the bacteria and the type of substrate determine the final gas composition.

(C) During the production of biogas,methanogenic bacteria (methanogens) act on cellulosic materials present in organic waste.
These bacteria grow anaerobically on cellulosic material and produce a large amount of methane $(CH_4)$,along with carbon dioxide $(CO_2)$ and hydrogen $(H_2)$.
Therefore,methane is the primary and most abundant gas produced in biogas.

(B) The Khadi and Village Industries Commission is a statutory body formed by the Government of India under the Act of Parliament,'Khadi and Village Industries Commission Act of $1956$'.
It is commonly abbreviated as $KVIC$.
This organization is involved in the development and promotion of khadi and village industries,often in coordination with other agencies for rural development,including the implementation of biogas programs in rural areas.

(B) $Biogas$ plant is a facility that processes organic waste through anaerobic digestion.
This process produces $Biogas$ (primarily $CH_4$),which serves as a renewable source of energy for cooking and lighting.
The residual slurry left after the digestion process is rich in nutrients and is used as high-quality organic fertilizer for crops.

(B) In the process of biogas production,the remaining waste material after the anaerobic digestion of organic matter is known as spent slurry. This spent slurry is rich in nitrogen,phosphorus,and potassium,making it an excellent organic fertilizer for crops. Therefore,it is removed from the biogas plant and used as manure or fertilizer in fields.

(B) Biogas is a mixture of gases (containing predominantly $CH_4$) produced by the microbial activity in the absence of oxygen.
Methanogens,such as $Methanobacterium$,are anaerobic bacteria that grow on cellulosic material.
These bacteria are commonly found in the anaerobic sludge during sewage treatment and in the rumen (a part of the stomach) of cattle.
In the rumen,these bacteria help in the breakdown of cellulose and play an important role in the nutrition of cattle.
Therefore,methanogens are the primary organisms used in biogas plants to produce methane gas from organic waste.

(D) biogas plant consists of a concrete tank (digester) in which bio-wastes are collected and a slurry of dung is fed.
$1$. The concrete tank is filled with a slurry of cow dung and organic waste (agricultural waste,plant residues,etc.).
$2$. Methanogens (like $Methanobacterium$) are anaerobic bacteria that grow in this slurry and produce biogas.
$3$. Therefore,the primary materials filled into the tank are cow dung and organic waste,which serve as the substrate for the methanogenic bacteria.
$4$. Thus,the correct combination is $(ii)$ and $(iv)$.

(B) In rural areas,the $Biogas$ plant is highly significant for both economic and sanitation reasons.
$1$. Economic Importance: It provides a cheap and renewable source of energy (methane) for cooking and lighting,reducing dependence on firewood or expensive fuels.
$2$. Sanitation: It effectively manages animal dung and agricultural waste,which helps in maintaining hygiene and preventing the spread of diseases in rural environments.
$3$. Fertilizer: The spent slurry left after biogas production serves as an excellent organic fertilizer for crops,improving soil fertility.

(A) $1$. Biogas is a mixture of gases (predominantly $CH_4$) produced by the microbial activity.
$2$. Certain bacteria,which grow anaerobically on cellulosic material,produce large amounts of $CH_4$,$CO_2$,and $H_2$. These bacteria are collectively called methanogens.
$3$. Methanogens are commonly found in the anaerobic sludge during sewage treatment and in the rumen (a part of the stomach) of cattle.
$4$. The excreta (dung) of cattle,commonly called 'gobar',is rich in these bacteria. Therefore,cow dung is used for the production of biogas.
$5$. Thus,both Assertion $A$ and Reason $R$ are true,and $R$ is the correct explanation of $A$.

(B) In the process of biogas production,anaerobic bacteria (methanogens) decompose organic matter like cellulose,hemi-cellulose,and lipids. However,$Lignin$ is a complex organic polymer that is highly resistant to microbial degradation under anaerobic conditions. Therefore,it remains largely undigested in the biogas plant slurry.

(C) Biogas is a mixture of gases (predominantly $CH_4$) produced by the microbial activity of methanogens.
Methanogens are anaerobic bacteria that grow in anaerobic conditions,such as in the rumen of cattle and in sewage treatment plants.
They break down cellulosic material to produce large amounts of $CH_4$,$CO_2$,and $H_2$.
Therefore,the correct option is $C$.

(C) Gobar gas, also known as biogas, is produced by the anaerobic breakdown of organic matter (like animal dung) by methanogenic bacteria. The primary component of this gas is methane $(CH_4)$, which typically constitutes $50-70\%$ of the total volume. Other components include carbon dioxide $(CO_2)$, hydrogen $(H_2)$, and traces of hydrogen sulfide $(H_2S)$.

(A) $1$. Herbivores,such as cattle,consume a diet rich in cellulose.
$2$. In the rumen (a part of the stomach) of these animals,certain bacteria called methanogens (e.g.,Methanobacterium) are present.
$3$. These methanogens anaerobically break down cellulose,which results in the production of large amounts of methane $(CH_4)$ along with $CO_2$ and $H_2$.
$4$. This methane is then released into the atmosphere through the animal's digestive tract.
$5$. Therefore,both the assertion and the reason are true,and the reason correctly explains why herbivores release methane.

(B) The biogas plant is highly significant for rural areas because it serves two main purposes:
$1$. Economic: It provides a cheap and renewable source of energy (methane) for cooking and lighting.
$2$. Sanitation: It effectively utilizes animal dung and agricultural waste,which helps in maintaining hygiene and reducing the spread of pathogens in the environment.

(A) Biogas is a mixture of gases,predominantly methane $(CH_4)$,produced by the microbial activity of methanogens (e.g.,Methanobacterium) during the anaerobic breakdown of cellulosic material. These bacteria grow anaerobically on cellulosic material and produce large amounts of methane along with $CO_2$ and $H_2$. Therefore,methane is the primary component.

(D) Biogas is a mixture of gases produced by the microbial activity of methanogens,which are anaerobic bacteria.
These bacteria grow on cellulosic material and produce large amounts of methane,$CO_2$,and $H_2$.
Therefore,biogas primarily consists of methane $(CH_4)$,carbon dioxide $(CO_2)$,and hydrogen $(H_2)$.

(B) The group of bacteria responsible for the production of biogas is known as $Methanogens$.
These bacteria are anaerobic and are commonly found in the anaerobic sludge during sewage treatment and in the rumen of cattle.
They produce $CH_4$ (methane) along with $CO_2$ and $H_2$ as a result of the anaerobic breakdown of cellulosic material.

(B) Biogas is a mixture of gases (containing predominantly $CH_4$) produced by the microbial activity and may be used as fuel.
Cattle dung is rich in methanogens,which are bacteria that grow anaerobically on cellulosic material and produce large amounts of $CH_4$,$CO_2$,and $H_2$.
Since cattle dung is commonly referred to as 'gobar' in India,the biogas produced from it is popularly known as 'gobar gas'.

(B) biogas plant consists of a concrete tank (digester) that is $10-15$ feet deep,in which bio-wastes are collected and a slurry of dung is fed. $A$ floating cover is placed over the slurry,which keeps on rising as the gas is produced in the tank due to the microbial activity of methanogens. In metric units,this depth is approximately $3$ to $5$ meters.

(D) biogas plant consists of a concrete tank (digester) in which bio-wastes are collected and a slurry of dung is fed.
This mixture of biological waste and cow dung serves as the substrate for methanogenic bacteria.
These bacteria break down the organic matter under anaerobic conditions to produce biogas,which is a mixture of gases like $CH_4$,$CO_2$,and $H_2$.
Therefore,both biological waste and cow dung are used in the process.