Diversity of bacteria and archaea in the deep-sea low-temperature hydrothermal sulfide chimney of the Northeastern Pacific Ocean

Abstract

Our knowledge of the diversity and role of hydrothermal vents microorganisms has considerably expanded over the past decade, while little is known about the diversity of microorganisms in low-temperature hydrothermal sulfide chimney. In this study, denaturing gradient gel electrophoresis (DGGE) and 16S rDNA sequencing were used to examine the abundance and diversity of microorganisms from the exterior to the interior of the deep sea low-temperature hydrothermal sulfide chimney of the Northeastern Pacific Ocean. DGGE profiles revealed that both bacteria and archaea could be examined in all three zones of the chimney wall and the compositions of microbial communities within different zones were vastly different. Overall, for archaea, cell abundance was greatest in the outermost zone of the chimney wall. For bacteria, there was no significant difference in cell abundance among three zones. In addition, phylogenetic analysis revealed that Verrucomicrobia and Deltaproteobacteria were the predominant bacterial members in exterior zone, beta Proteobacteria were the dominant members in middle zone, and Bacillus were the abundant microorganisms in interior zone. As to archaea, the middle and exterior were dominated by unclassified archaea, while interior zone was dominated by methanogens. Taken together, these results show that there was a transition in the composition of microbial communities across the sulfide chimney wall. Our findings provide helpful information for understanding the diversity and phylogeny of microorganisms in the deep-sea low temperature hydrothermal sulfide chimney.

Key words: Low-temperature hydrothermal sulfide chimney, bacteria, archaea, DGGE.