[SEMINAR] Isolation and characterization of a novel sulfur-disproportionating bacterium for advancing biochemical research

Title: Isolation and characterization of a novel sulfur-disproportionating bacterium for advancing biochemical research

Speaker: Tomohiro Watanabe

From: Hokkaido University, Japan

Abstract: Sulfur-disproportionating bacteria derive energy from the disproportionation of thiosulfate, tetrathionate, sulfite, or elemental sulfur, and the molecular basis of their energy metabolism is a subject of scientific interest. During field sampling at a hot spring in Hokkaido, we discovered a unique pond exhibiting strong gradients of water temperature due to the mixing of hot spring water (~58°C) and cold stream water. Within this environment, we observed the development of microbial mats, and successfully isolated a novel sulfur-disproportionating bacterium thriving in a black-colored mat. The new isolate grew through the disproportionation of elemental sulfur, thiosulfate, and sulfite. Additionally, it exhibited respiratory growth by coupling nitrate reduction with the oxidation of H2 or elemental sulfur. The optimum temperature for its growth was 45–48°C. Its growth rate and final cell density were promising, and we are currently investigating methods for large-scale cultivation with the aim of advancing biochemical research. In this presentation, I will discuss the targets of biochemical research on sulfur-disproportionating bacteria based on their genomes.

Short description of speaker: Tomohiro Watanabe studied microbial ecology involved in sulfur cycling and obtained his Ph.D in 2014 from Hokkaido University. He moved to Max-Planck-Institute for Terrestrial Microbiology to study enzymes involved in methanogenesis from 2016 to 2020. He is currently an assistant professor of Group Microbial Ecology at Institute of Low Temperature Science, Hokkaido University. His research interests are catalytic mechanism, diversity and evolution of energy metabolism in environmental microbes.