title: Detection of anaerobic carbon monoxide-oxidizing thermophiles in hydrothermal environments.
abstract: Carboxydotrophic anaerobic thermophiles have been isolated from various hydrothermal environments and are considered to be important carbon monoxide (CO) scavengers or primary producers. However, the ecological factors that influence the distribution, abundance and CO-oxidizing activities of these bacteria are poorly understood. A previous study detected the carboxydotrophic bacteria Carboxydothermus spp. in a hot spring sample and found that they constituted up to 10% of the total bacterial cells. In this study, we investigated environmental features, potential microbial CO-oxidation activities and the abundance of Carboxydothermus spp. in various hot springs to determine environmental factors that affect CO oxidizers and to see whether Carboxydothermus spp. are common in these environments. We detected potential microbial CO-oxidation activities in samples that showed relatively high values of total organic carbon, total nitrogen, oxidation-reduction potential and soil-water content. The abundance of Carboxydothermus spp. did not correlate with the presence of potential microbial CO-oxidation activities; however, Carboxydothermus spp. were detected in a wide range of environments, suggesting that these bacteria are widely distributed in spite of the relatively low population size. This study implies that thermophilic CO oxidizers occur in a wide range of environments and oxidize CO in somewhat oxidative environments rich in organic matter.
authors.affiliation: Laboratory of Marine Microbiology, Graduate School of Agriculture, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan.
authors.forename: Yasuko
authors.initials: Y
authors.lastname: Yoneda
authors.affiliation: Laboratory of Marine Microbiology, Graduate School of Agriculture, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan.
authors.forename: Sanae I
authors.initials: SI
authors.lastname: Kano
authors.affiliation: Laboratory of Marine Microbiology, Graduate School of Agriculture, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Yoshida
authors.affiliation: Laboratory of Marine Microbiology, Graduate School of Agriculture, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan.
authors.forename: Eitaro
authors.initials: E
authors.lastname: Ikeda
authors.affiliation: Laboratory of Marine Microbiology, Graduate School of Agriculture, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan.
authors.forename: Yuto
authors.initials: Y
authors.lastname: Fukuyama
authors.affiliation: Laboratory of Marine Microbiology, Graduate School of Agriculture, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan.
authors.forename: Kimiho
authors.initials: K
authors.lastname: Omae
authors.affiliation: Laboratory of Marine Microbiology, Graduate School of Agriculture, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan.
authors.forename: Shigeko
authors.initials: S
authors.lastname: Kimura-Sakai
authors.affiliation: Laboratory of Marine Microbiology, Graduate School of Agriculture, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Daifuku
authors.affiliation: Laboratory of Soil Science, Graduate School of Agriculture, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan.
authors.forename: Tetsuhiro
authors.initials: T
authors.lastname: Watanabe
authors.affiliation: Laboratory of Marine Microbiology, Graduate School of Agriculture, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan sako@kais.kyoto-u.ac.jp.
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Sako
mesh_terms: D002245:Carbon Dioxide / Q000378:metabolism; D002248:Carbon Monoxide / Q000378:metabolism*; D004777:Environment; D000068536:Bacillota / Q000302:isolation & purification* / Q000378:metabolism; D045482:Hot Springs / Q000382:microbiology*; D010084:Oxidation-Reduction
chemical_list: D002245:Carbon Dioxide; D002248:Carbon Monoxide
keywords: carbon monoxide; carbon monoxide dehydrogenase; carboxydotroph; hot spring; thermophile