are underway on methanogens (Blasco-Gómez et al. 2017), and various such
features about the characterization of strain as well as simple genetic tool developments are still going to proliferate (Voegeli et al. 2009). Table 3.2 shows the sources
of methanogenic microorganisms.
Fig. 3.2 Digestion process (anaerobic) life cycle
Table 3.1 Steps in anaerobic digestion process
S. No. Step
Process and reaction
1.
Hydrolysis
Breaking down of complex to simpler molecules in the presence of
water
Carbohydrates/lipids/proteins + water ! sugars/fatty acids/amino
acids
2.
Acidogenesis
Conversion of simpler molecules to volatile acids
Sugars/fatty acids/amino acids ! volatile acids
3.
Acetogenesis
Production of acetates as well as acetic acid from volatile acids
Volatile acids ! acetates as well as acetic acid
4.
Methanogenesis Biogas generation from acetates and acetic acid
Acetates and acetic acid ! biogas
56
S. Sivamani et al.