ENVIRONMENTAL-IMPACT OF BIOMETHANOGENESIS

The environmental impact of biomethanogenesis is related to its ecolog ical role, accumulation and effect as a greenhouse gas, and applicatio n in anaerobic digestion for conversion of biomass and wastes to metha ne and compost. Biological formation of methane is the process by whic h bacteria decompose organic matter using carbon dioxide as an electro n acceptor in the absence of dioxygen or other electron accepters. Thi s microbial activity is responsible for carbon recycling in anaerobic environments, including wetlands, rice fields, intestines of animals s ediments, and manures. The mixed consortium of microorganisms involved includes a unique group of bacteria, the methanogens, which may be co nsidered to be in a separate kingdom based on genetic and phylogenetic variance from all other life forms. Because methane is a significant and increasing greenhouse gas, its source fluxes and their potential r eduction are of concern. Biomethanogenesis may be harnessed for reduct ion of wastes and conversion of renewable resources to significant qua ntities of substitute natural gas which could mitigate carbon dioxide and other pollutants related to use of fossil fuels.