屋我地島沿岸海底のメタン湧出域から採取したバクテリアマットの微生物群集構造

Abstract

A piece of bacterial mat was collected from the seafloor at 2m water depth around a methane seep off Yagaji Island, located at the northern part of Okinawa Island, on which bacterial 16S rRNA gene analysis was conducted. Almost half of the clone sequences of the 16S rRNA gene from the bacterial mat sample are likely from sulfur-oxidizing bacteria, while no clone of methane-oxidizing bacterium was detected. Nevertheless, a bacterial cell with the distinctive appearance of methane-oxidizing bacteria was found using microscopy. However, methane-oxidizing bacteria appear to be a minor component in the bacterial mat community investigated. The dominant clones from the bacterial mat were closely related to those detected in the shallow-water hydrothermal systems in the South Tonga Arc. This result implies that sulfur-oxidizing bacteria specific to shallow waters may exist in the bacterial mats around the methane seep off Yagaji Island.