Metagenomic insights into the dominant Fe(II) oxidizing Zetaproteobacteria from an iron mat at Lo´ihi, Hawai´l
Frontiers in Microbiology, (March 2013)DOI: 10.3389/fmicb.2013.00052
Abstract
<p><em>Zetaproteobacteria</em> are among the most prevalent Fe(II)-oxidizing bacteria (FeOB) at deep-sea hydrothermal vents; however, knowledge about their environmental significance is limited. We provide metagenomic insights into an iron mat at the Lo´ihi Seamount, Hawai´l, revealing novel genomic information of locally dominant <em>Zetaproteobacteria</em> lineages. These lineages were previously estimated to account for ~13\% of all local <em>Zetaproteobacteria</em> based on 16S clone library data. Biogeochemically relevant genes include nitrite reductases, which were previously not identified in <em>Zetaproteobacteria</em>, sulfide:quinone oxidases, and ribulose-1,5-bisphosphate carboxylase (RuBisCo). Genes assumed to be involved in Fe(II) oxidation correlate in synteny and share 87\% amino acid similarity with those previously identified in the related <em>Zetaproteobacterium</em> <em>Mariprofundus ferrooxydans</em> PV-1. Overall, <em>Zetaproteobacteria</em> genes appear to originate primarily from within the <em>Proteobacteria</em> and the Fe(II)-oxidizing <em>Leptospirillum</em> spp. and are predicted to facilitate adaptation to a deep-sea hydrothermal vent environment in addition to microaerophilic Fe(II) and H<sub>2</sub>S oxidation. This dataset represents the first metagenomic study of FeOB from an iron oxide mat at a deep-sea hydrothermal habitat.</p>