Comprehensive Analysis of Physiological Capabilities, Ecological Functions and Ecological Niches of Acidophilic Microorganisms

• Applicant: Professor Dr. Johannes Gescher
• Subject Area: Microbial Ecology and Applied Microbiology
• Term: from 2011 to 2014
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 193860825

Here we propose to investigate a stalactite-like bacterial community from an abandoned pyrite mine in Elbingerode (Germany). The community is fueled exclusively by the decomposition of pyrite (FeS2) and is embedded in a mixture of extracellular polysaccharides and products of secondary mineraliza-tion events. The majority of bacterial species that live in and build up this spatially confined environ-ment are dependent on the catalysis of iron oxidation and reduction reactions. Our proposal aims at dissecting the biogeochemical and environmental factors that contribute to the formation of ecological niches for different iron oxidizing and reducing bacteria as well as a novel group of archaea with so far undiscovered physiological capabilities. We strive to understand these factors in this particular biofilm due to its spatially highly limited location and the moderate number of microbial species present. These attributes give the community a model character for a multitude of acid rock drainage dependent consortia. Integration of results from bio/geochemical characterization and metagenomic and metaproteomic analysis with fluorescent in situ hybridization (FISH) experiments using probes towards different iron oxidizing and reducing organisms and archaea will lead to a model for the ecological niches and the potential interspecies dependence within the biofilm. These models will be tested with enrichment and isolation experiments in which we will mimic the environmental niches of different bacterial and archaeal strains to isolate them from the bacterial community.

• DFG Programme: Research Grants