Page 95 - Microbial methane cycling in a warming world From biosphere to atmosphere Michiel H in t Zandt

Figure 3. Proposed scheme illustrating the potential of the microbial community to convert sub- bituminous coal to methane. The groundwater level is 65 m below ground level and the coal bearing layers are located 80 m below ground level. Fungi related to the Basidiomycota possess the capacity for coal biosolubilization. The bacterial community has the capacity for complex organic compounds degradation to volatile fatty acids (VFAs). Iron was detected as potential electron acceptor for Desulfovibrio and Geobacter, and sulfate could play a role only in the first three months. Acetoclastic Methanothrix spp. were the dominant methanogens in the coal well. Although the potential for bioconversion of the coal matrix was found, coalbed methanogenesis could not be observed.
Both observations make it questionable whether nutrient and acetate amendment will help to sustainably generate coalbed methane from non-producing coal wells, even if such amendments stimulate the microbial growth in general and help to bioaugment relevant microorganisms such as acetoclastic methanogens or complex organic compound degraders. In general, biological methane production from coal is a promising alternative to direct coal burning as it reduces
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