Decomposition methanogenesis

The anaerobic decomposition of organic matter by fermentation, methanogenesis (methane formation) and sulfate respiration is exemplified in Table 3.2. 

FIGURE 5.33 Pathways involved in organic matter decomposition during methanogenesis. 

Snppress other microbial processes that regnlate organic matter decomposition (e.g., sulfate reduction and methanogenesis)... 

In soils, methane production rates are inhibited at soil depths with intense cycling of iron (Ratering and Schnell, 2000). However, the utilization of Fe(III) oxides depends on the appropriate form that is readily available or on microbial communities. In soils with a limited availability of Fe(III) oxides and other electron acceptors, methanogenesis is the dominant pathway to regulating organic matter decomposition and ultimately a major methane source to the atmosphere. 

The other methanogenesis processes are of secondary value. They may include methylotrophic methanogenesis and methyl reduction. In the former case as the substrate serve simple compounds with methyl groups like methanol (CH OH), methylamine (CH NH ) and dimethylsulphide (CHjSCHj), etc., decomposed by disproportionation. An example is a methanol decomposition reaction ... 

Acetidastic methanogenesis are also archaea, for which major substrate is either only acetate at its low concentrations (Methanosaeta sp) or both acetate and methanol and other compounds with one carbon atom, and also mix of Fi and CO at high acetate concentrations (Methanosardna sp.) (Westerholm, 2012). The process of acetidastic methanogenesis itself is viewed as decomposition of acetate into methyl (CH ) and carboxylic (COOH) groups. The former converts into CH, the latter is oxidized to CO. ... 

Decomposition of organic matter is a dynamic process. The oxidation of organic matter eventually produces CO2 and in anaerobic environments microbiological process cdled methanogenesis produces methane (CH4) gas [24]. 

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