Initial Investigations into the Microbial Diversity at Brothers Seamount, Kermadec-Tonga Arc, New Zealand

Brothers Seamount, a submarine volcano located along the Kermadec-Tonga Arc in New Zealand, results from intraoceanic plate subduction and as such, exhibits substantially different chemistries to those found on mid-ocean spreading ridges. Furthermore, Brothers Seamount has two major venting sites that exhibit disparate geochemistries. Combined, these factors suggest that microbial diversity studies of Brothers Volcano have potential to identify an array of novel microbial species. Two manned submarine expeditions, the first in November 2004 with the JAMSTEC R/V Yokosuka and Shinkai 6500 and the second in April/May 2005 with the HURL R/V Kiamikai-o-Kanaloa and Picses V dove on the Brothers Seamount a total of 9 times collecting vent, sediment and fluid samples used, in part, for microbial enrichments and molecular diversity studies. Clone libraries of the 16S rRNA gene were generated using DNA extracts from multiple samples at the two venting sites on Brothers Volcano. So far, more than 60 unique bacterial sequence types have been found out of an overall clone count of greater than 200 including , a, and -Proteobacteria, and several Planctomycetes. The -Proteobacteria account for most of the diversity. Archaeal 16S rRNA clone banks, including amplifications using primers specific for the phylum Nanoarchaeota, are currently being constructed, with preliminary results showing a diverse range of archaeal species.