AQUIFER VS. COAL-DERIVED METHANOGENS IN PALEOCENE FORT UNION FORMATION COALS – MOLECULAR TECHNIQUE-BASED INFORMATION AND ITS ECOLOGICAL IMPLICATIONS

Most studies focusing on the stimulation and replenishment of coalbed methane (CBM) in low-rank coals have used contemporary aquifer-derived methanogens, where test coals are amended with needed nutrients and complementary energetic constituents (oxidants, reductants, etc.) to allow methanogenesis to take place. The results of such experiments are largely predictable; with creation of desired functional environments, methanogenesis can be stimulated. Molecular analyses of these aquifer microbial communities are generally based on bulk-extracted nucleic acids and 16S rDNA analyses, where there is the possibility of molecular information being derived (1) from a variety of active/inactive cells that may not be able to function in a particular environment and (2) from non-cellular nucleic acid sources.

In our studies using molecular techniques, we are concerned with the characterization of possible indigenous coal-derived methanogens that have not been impacted by contemporary environmentally-derived methanogens. If molecular evidence indicates that additional indigenous methanogen sequence diversity might be present compared with available information on only the methanogens from aquifers and other contemporarily impacted environments, then a more diverse group of methanogens may be present. To assist in recovering any such environmentally isolated coal methanogens, diffusion-based incubation systems have been used to attempt to better duplicate functional constituent concentrations and flux rates in methanogenic environments. Based on nested polymerase chain reaction protocols, molecular analyses of indigenous coal bed materials have indicated that putative deep-rooted methanogen sequences are present that may represent novel microbes, possibly with a greater potential for use in CBM stimulation. A better understanding of the characteristics of these possible indigenous methanogens to complement contemporary aquifer-derived methanogenic microbial communities may make it possible to devise new technologies for the management and development of CBM resources in the future.