Bacterial diversity in deep-sea sediments from two stations in the east Pacific polymetallic nodule province

Abstract:

[Objective] The objective of this study was to assess bacterial diversity in sediment samples from two stations (WBC1305 and WBC1316A) in the Pacific polymetallic nodule province.[Methods] The environmental total DNAs were extracted, and 6 bacterial 16S rRNA gene libraries were generated from 6 sediment layers. The Shannon diversity index and Simpson dominance index were calculated for each bacterial community and then compared. The bacterial community structure of each sediment sample was analyzed, and the results were used to construct phylogenetic trees.[Results] In total, 533 bacterial clones were obtained from 6 bacterial clone libraries. Among these 533 clones, 472 clones could be assigned to 16 phylogenetic groups (Acidobacteria, Actinobacteria, Alpha, Beta, Delta, gamma-Proteobacteria, Bacteroidetes, Chloroflexi, Firmicutes, Gemmatimonadetes, Nitrospirae, Planctomycetes, Elusimicrobia, Hydrogenedentes, Chlorobi, and Nitrospinae), whereas the remaining 61 clones could not be classified into any known groups.[Conclusion] The bacterial communities in sediments from WBC1305 are dominated mainly by gamma-Proteobacteria and from WBC1316A by Firmicutes. In addition, the bacterial community structure at WBC1316A is more abundant and complex than that at WBC1305.