title: Transcriptome analyses of metabolic enzymes in thiosulfate- and hydrogen-grown Hydrogenobacter thermophilus cells.
abstract: Hydrogenobacter thermophilus is a chemolithoautotroph that utilizes not only hydrogen (H(2)) but also thiosulfate as sole source of energy and assimilates carbon dioxide via the reductive tricarboxylic acid (RTCA) cycle. We systematically carried out transcriptome analysis of metabolic enzymes in both H(2)- and thiosulfate-grown H. thermophilus cells. The analysis indicated that the expression of hydrogenase genes is repressed under thiosulfate oxidation conditions as compared with H(2) oxidation conditions. This was confirmed by enzyme assay. In contrast, some genes for sulfur metabolism, including sox genes, showed almost the same expression levels under both conditions. In addition, the genes for the RTCA cycle showed high expression levels under both conditions. It was suggested that sulfur metabolism and the RTCA cycle function as forms of basal metabolism, and H(2) oxidation is inducible. Switching of H(2) oxidation can be advantageous for the lifestyle of this bacterium in nature.
authors.affiliation: Department of Biotechnology, Graduate School of Agricultural and Life Science, The University of Tokyo, 1-1-1 Yayoi, Tokyo 113-8657, Japan.
authors.forename: Yuya
authors.initials: Y
authors.lastname: Sato
authors.forename: Haruna
authors.initials: H
authors.lastname: Kanbe
authors.forename: Hirosuke
authors.initials: H
authors.lastname: Miyano
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Sambongi
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Arai
authors.forename: Masaharu
authors.initials: M
authors.lastname: Ishii
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Igarashi
mesh_terms: D001419:Bacteria / Q000201:enzymology / Q000235:genetics*; D002245:Carbon Dioxide / Q000378:metabolism; D002952:Citric Acid Cycle / Q000502:physiology; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D045482:Hot Springs / Q000382:microbiology; D006358:Hot Temperature; D006859:Hydrogen / Q000378:metabolism*; D006864:Hydrogenase / Q000378:metabolism*; D010084:Oxidation-Reduction; D013885:Thiosulfates / Q000378:metabolism*; D059467:Transcriptome
chemical_list: D013885:Thiosulfates; D002245:Carbon Dioxide; D006859:Hydrogen; D006864:Hydrogenase