Question

The first step in the biogas generation is
(a) Aerobic hydrolysis of polymers
(b) Anaerobic hydrolysis of polymers
(c) Conversion of monomers into organic acids
(d) Conversion of organic acids into monomers

Answer 1

Hint Biogas is also known as gobar gas which is produced by the anaerobic breakdown of waste biomass. The main component of biogas is methane and other components include carbon dioxide, hydrogen, nitrogen, and hydrogen sulfide.

Complete Answer:
The formation of biogas is a three-step anaerobic process such as Decomposition, acidogenesis, and methanogenesis.
The organic compound of waste biomass composed of lipids, proteins, cellulose, hemicellulose, and lignin, in which lignin does not get decomposed by anaerobic process and breakdown of cellulose is slow. In the case of decomposition, the facultative decomposer becomes active and secrete hydrolytic enzymes lipases, cellulases, proteases, and peptidases. This enzyme helps to break down complex organic components into soluble substance monomers.
In acidogenesis, these monomers changed into organic acids with help of fermenting microbes. The common organic acid is acetic acid, hydrogen, and carbon dioxide are a byproduct.
At the time of methanogenesis methane-producing bacteria become active which acts on microbial digestion and fermentation. Biogas collects in floating gas holders which connect through pipes to households.

Additional information:
Biogas has several advantages, it produces no foul smells, it does not consist of a pathogen, it does not cause pollution, it works as both fuel and manure, and it can be used in cooking, lightening, engines, etc.

So, the correct answer is the ‘Conversion of organic acids into monomers’.

Note: Biogas not only obtained from cow dung, but it also made up of night soil, farm refuse, water weeds, and organic wastes. It was converted into a slurry with 90% water and fed to the digester.