DETECTION OF METHANOGENS AND METHANOTROPHS IN NATURAL ENVIRONMENTS

The role of methane as a greenhouse gas and the contribution of bacter ia to the production (methanogenesis) and destruction (methane oxidati on) of methane is described. Using experimental approaches based on DN A sequences identifying either methanogen-specific or methanotroph-spe cific gene sequences methods were developed to broaden the detection a nd identification of methane metabolizing bacteria in natural environm ents. These methods were focused on blanket bog peat but are suitable for other environments. In addition to group specific 16S rRNA DNA seq uences, specific functional gene probes based on methane coenzyme redu ctase sequences for methanogens and methane monooxygenase sequences fo r methanotrophs, were developed. These sequences were used in PCR-base d protocols to detect and amplify specific gene sequences from the tot al DNA isolated from transverse sections of blanket bog peat. This per mitted the analysis of the vertical distribution of methanogen and met hanotroph populations, discrimination between different sub-sets of th ese populations, and the identification of novel organisms not previou sly detected by culture-based methods.