As described in the diagram above, every substrate gets converted into a unique
bio-product by the action of enzyme groups released by various specific microbial
strains. The table given below gives an insight into a series of different substrate
groups along with their chemical composition, including the amount of carbon and
nitrogen contents. Several various sources of these substrates are also shown,
i.e. various industries (pulp, paper, and food), wastage, and some other materials.
Substrates require optimum temperatures for their degradation because of their
enzyme and microbe specific nature; that is why the temperature requirements of
each of the substrate groups listed in the Table 2.3 are clearly mentioned.
2.4.3 Active Microorganisms at Different Stages of Biogas Process
The existence of numerous diverse microbiological species is vital for the functioning of the biogas generation process and for producing end products: methane/
hydrogen gas. All the microbes involved in action need to work similarly collectively (Angelidaki et al. 2011; Schnürer et al. 2016).
The microbial strains that are dynamically involved in the entire process are
illustrated as Fig. 2.7.
Proteases
Amino Acids
Acyl-CoA
dehydrogenase
Fatty Acids + Ammonia
Proteins
RCH(NH 2 )COOH
Lipids
CH 3 (CH 2 ) n COOH
Lipases
Laccases; Manganese
peroxidases & Lignin
peroxidases
Lignin
(C 31 H 34 O 11 ) n
Celluloses
(C 6 H 10 O 5 ) n
Substrates
Bacteria i.e. Bacteroides,
Clostridium, Streptococcus
Fusobacterium,
Butyrivibrio, Selenomonas
Bacteria i.e. Micrococcus,
Anaerovibrio, Clostridia,
Syntrophomonas
Ascomycete &
Basidiomycete Fungi i.e.
Phanerochaete, Botrvtis
Fungi i.e. Aspergillus,
Penicillium,
Trichoderma, Fusarium
Hemicellulases; endo-1,4-b-xylanase,
b-xylosidase, a-glucuronidase,
acetylxylan esterase
Hemicelluloses
(Pentoses+Hexoses+Sugar Acids)
Cellulases;
Endoglucanases,
b-glucosidases
cellobiohydrolases
Pectin Degrading Enzymes:
Pectinases, Pectin depolymerase,
Polygalacturonase
Pectins (Homo-galacturonic
Acid Backbone+Neutral
Sugar Side Chains)
Bacteria i.e. Selenomonas,
Bacteroides, Clostridium,
Campylobacter, Peptococcus
Fungi i.e. Penicillium,
Aspergillus, Fusarium
Bacteria i.e. Fusobacterium,
Clostridium, Bacillus
Filamentous Fungi i.e.
Trichoderma, Aspergillus,
Fusarium, Phanerochaete,
Penicillium
Bacteria i.e. Pyrococcus,
Bacillus, Clostridium,
Streptomyces
Bacteria i.e.
Fusobacterium, Bacillus
Clostridium, Butyrivibrio
γ-Protobacteria; Escherichia,
Acinitobacter, Citrobacter,
Psuedomonas, Burkhloderia
α- Protobacteria
Ochrobactrum, Sphingobium,
Brucella, Paracoccus
Bacteria i.e. Actinomycetes
Microbacterium, Nocardia
Streptomyces, Rhodococcu
Fig. 2.6 Different substrates, their chemical composition and Microbial strains that produce
specific enzymes for the substrate degradation
2 Microbial and Biotechnological Advancement in Biogas Production
47
bio-product by the action of enzyme groups released by various specific microbial
strains. The table given below gives an insight into a series of different substrate
groups along with their chemical composition, including the amount of carbon and
nitrogen contents. Several various sources of these substrates are also shown,
i.e. various industries (pulp, paper, and food), wastage, and some other materials.
Substrates require optimum temperatures for their degradation because of their
enzyme and microbe specific nature; that is why the temperature requirements of
each of the substrate groups listed in the Table 2.3 are clearly mentioned.
2.4.3 Active Microorganisms at Different Stages of Biogas Process
The existence of numerous diverse microbiological species is vital for the functioning of the biogas generation process and for producing end products: methane/
hydrogen gas. All the microbes involved in action need to work similarly collectively (Angelidaki et al. 2011; Schnürer et al. 2016).
The microbial strains that are dynamically involved in the entire process are
illustrated as Fig. 2.7.
Proteases
Amino Acids
Acyl-CoA
dehydrogenase
Fatty Acids + Ammonia
Proteins
RCH(NH 2 )COOH
Lipids
CH 3 (CH 2 ) n COOH
Lipases
Laccases; Manganese
peroxidases & Lignin
peroxidases
Lignin
(C 31 H 34 O 11 ) n
Celluloses
(C 6 H 10 O 5 ) n
Substrates
Bacteria i.e. Bacteroides,
Clostridium, Streptococcus
Fusobacterium,
Butyrivibrio, Selenomonas
Bacteria i.e. Micrococcus,
Anaerovibrio, Clostridia,
Syntrophomonas
Ascomycete &
Basidiomycete Fungi i.e.
Phanerochaete, Botrvtis
Fungi i.e. Aspergillus,
Penicillium,
Trichoderma, Fusarium
Hemicellulases; endo-1,4-b-xylanase,
b-xylosidase, a-glucuronidase,
acetylxylan esterase
Hemicelluloses
(Pentoses+Hexoses+Sugar Acids)
Cellulases;
Endoglucanases,
b-glucosidases
cellobiohydrolases
Pectin Degrading Enzymes:
Pectinases, Pectin depolymerase,
Polygalacturonase
Pectins (Homo-galacturonic
Acid Backbone+Neutral
Sugar Side Chains)
Bacteria i.e. Selenomonas,
Bacteroides, Clostridium,
Campylobacter, Peptococcus
Fungi i.e. Penicillium,
Aspergillus, Fusarium
Bacteria i.e. Fusobacterium,
Clostridium, Bacillus
Filamentous Fungi i.e.
Trichoderma, Aspergillus,
Fusarium, Phanerochaete,
Penicillium
Bacteria i.e. Pyrococcus,
Bacillus, Clostridium,
Streptomyces
Bacteria i.e.
Fusobacterium, Bacillus
Clostridium, Butyrivibrio
γ-Protobacteria; Escherichia,
Acinitobacter, Citrobacter,
Psuedomonas, Burkhloderia
α- Protobacteria
Ochrobactrum, Sphingobium,
Brucella, Paracoccus
Bacteria i.e. Actinomycetes
Microbacterium, Nocardia
Streptomyces, Rhodococcu
Fig. 2.6 Different substrates, their chemical composition and Microbial strains that produce
specific enzymes for the substrate degradation
2 Microbial and Biotechnological Advancement in Biogas Production
47