This project is focused on characterizing sulfate-reducing bacteria from boreal wetlands and submerged soils that are impacted by acid mine drainage. The unique feature of this study is the sampling of geographically distinct boreal ecosystems in Russia, Sweden, and Finland, with a view to finding sulfate-reducers with novel traits such as the ability to grow at low pH values and low temperatures. To our knowledge, a systematic search of acidophilic and psychrophilic sulfate-reducers in boreal environments has never before been undertaken. Sulfate-reducers from boreal sampling sites will be characterized by 16S rDNA based phylogeny, and those sulfate-reducers that are culturable and can be isolated in pure culture will be further characterized by conventional physiological approaches including metal resistance and various electron donor and electron acceptor conditions. Rates and stable isotopic composition of intermediates and products of sulfate reduction will be measured under boreal conditions in order to identify the geochemical role of sulfate-reducing bacteria. Ultimately, it is planned to develop mixed and pure cultures of sulfate-reducing bacteria from boreal environments that have potential application for bioremediation of acid mine drainage either in-situ or in stirred tank bioreactors.