An isolated microbial consortium is described that includes a first microbial consortium having Thermacetogenium phaeum to metabolize a complex hydrocarbon substrate into metabolic products comprising an acetate compound. The consortium also includes a second microbial consortium having a methanogen to convert the acetate compound into a final product that includes methane. Also, a method of increasing production of materials with enhanced hydrogen content. The method includes isolating Thermacetogenium phaeum from geologic formation water, culturing the isolated Thermacetogenium phaeum to increase the Thermacetogenium phaeum population, and introducing a consortium of the cultured Thermacetogenium phaeum, which may include spores of Thermacetogenium phaeum, into a hydrocarbon formation containing a complex hydrocarbon substrate.