Archaeal Community in the Hydrothermal System at Suiyo Seamount on the Izu-Ogasawara Arc

Archaeal communities in extreme environment have been analyzed by phylogenetic analysis using 16S rDNA gene and fluorescent whole cell in situ hybridization method. These culture-independent methods revealed archaeal communities with much higher diversities than those found by conventional culture methods. In this work we have extended the culture-independent method to the analysis of microbial diversity in a deep-sea hydrothermal system at Suiyo Seamount. In the Archaean Park Project supported by Special Coordination Fund, several holes were bored and cased in the crater of the Suiyo seamount on the Izu-Ogasawara arc (about 1,400 depth) in 2001 and 2002. Hydrothermal fluids form these cased holes and black smoker chimneys were sampled at various sites on Suiyo seamount. The fluids were filtered to collect the microbial cells. Filters and black smoker chimney samples were crushed and DNA was extracted and purified. The DNA was used to amplify archaeal 16S rDNA fragments by PCR using an archaea specific primer set. The PCR fragments were cloned and sequenced. Archaeal PCR clones of different samples will be compared.