Impact of Hydrothermal Vent Plumes on Microbial Community of Mid Indian Ocean Water Column Environment

Abstract

Depth distribution of microbial diversity in water columns of Indian Ocean was investigated. Seawater samples were obtained from 3 different area of mid-Indian Ocean by 500 m depth interval to near bottom layer and concentrated on membrane filter and amplicon sequencing was conducted. Predominant bacterial genera in the surface water were members of a typical oligotrophic ocean such as Prochlorococcus, Pelagibacter ubique, and Alteromonas macleodii. Proportion of a-Proteobacteria was substituted by r-Proteobacteria with increase of water depth. However, proportion of hydrothermal environments specific microorganisms was very low even in the water column displaying plume signal, but plenty of sulfur oxidizing e-Proteobacteria such as the genera Sulfurovum and Sulfurimonas was detected. The result implied that reduced sulfur species supplied into water column from hydrothermal vent and support growth of sulfur oxidizing bacteria.filter and amplicon sequencing was conducted. Predominant bacterial genera in the surface water were members of a typical oligotrophic ocean such as Prochlorococcus, Pelagibacter ubique, and Alteromonas macleodii. Proportion of a-Proteobacteria was substituted by r-Proteobacteria with increase of water depth. However, proportion of hydrothermal environments specific microorganisms was very low even in the water column displaying plume signal, but plenty of sulfur oxidizing e-Proteobacteria such as the genera Sulfurovum and Sulfurimonas was detected. The result implied that reduced sulfur species supplied into water column from hydrothermal vent and support growth of sulfur oxidizing bacteria.