This PhD project will focus on the microbial reduction of elemental sulfur at acidothermophilic conditions. The first target will be to obtain enrichments that produce H2S at low pH and high temperature. The community structure of ‘successful’ enrichment cultures will be determined, and specific strains will be isolated. Isolates of interest will then be characterized physiologically and genetically, and used for a more in-depth study of the mechanisms involved in elemental sulfur reduction. This project will be performed in collaboration with a PhD student at Environmental Technology.