Microbial Conversion of High-Rank Coals to Methane

It has been demonstrated recently that certain bacteria and fungi are capable of directly or indirectly converting low-rank coals into liquid and gaseous fuels. The Bureau of Mines has found preliminary evidence that indicates that microbial consortia are responsible for generating methane from bituminous coal. Building on this work, a study was undertaken to test selected anaerobic microbial consortia for their ability to degrade and produce methane from bituminous coals. Five consortia were collected from natural sources, including coal strip ponds, mine treatment areas, chemical waste deposits, and sewage sludge. Three coals were incubated into various media containing inocula from the consortia. At least three of the consortia showed an ability to produce methane from hard coals in the absence of yeast extract.