[B-GM22_30AM1] 地球惑星科学と微生物生態学の接点

[BGM22-06] 半閉鎖水塊における熱水プルームイオウ酸化独立栄養微生物SUP05の炭素、窒素循環への寄与

*砂村 倫成¹、髙木 善弘²、布浦 拓郎²、高井 研² (1.東京大学大学院理学系研究科地球惑星科学専攻、2.海洋研究開発機構)

キーワード：イオウ酸化微生物, 熱水プルーム, 窒素同化, ゲノム

In the deep sea hydrothermal plume, significantly elevated microbial biomass has been reported depending on chemolithoautotrophic activities by hydrothermal reduced chemicals. The potential energetic is sulfur, methane and hydrogen oxidation, and microbial production is up to date. The most important microbes in the plume is SUP05 phylotype (genus Thioglobes), which is known to have sulfur and H2 oxidation pathway, RubisCO carbon assimilation pathway, and denitrification pathways. In this study, we compared the bicarbonate and inorganic nitrogen species with SUP05 cell densities in the hydrothermal plume of the TOTO caldera hydrothermal field with half-closed water mass system in the Southern Mariana Trough. The cell densities of SUP05 is strong negative correlation with bicarbonate and nitrate, however, the correlation slope indicated the nitrogen assimilation but not the nitrogen respiration (denitrification). Only the nitrogen assimilation occurred in the plume is also supported by the lack of denitrification genes in the plume sample with the metagenomic analysis.