title: Phylogenetic diversity of nitrogen-utilizing genes in hydrothermal chimneys from 3 middle ocean ridges.
abstract: Nitrogen-metabolizing genes, including nitrogenase (nifH), periplasmic nitrate reductase (napA), and cytochrome cd 1-type nitrite reductase (nirS), were collected from hydrothermal chimney sulfides on 3 middle ocean ridges and compared for the first time. There was a clear phylogenetic distinction of these nifH genes between different hydrothermal ecosystems, which supported the colonization and potential adaptation by different nitrogen fixing microbes in those sulfides. In particular, in sulfides from low-temperature hydrothermal vents of the Southwest Indian Ocean Ridge, the prevalence of nifH genes appears to be attributed to sulfate-reducing bacteria, suggesting their ecological significance. Phylogenetic analysis of nitrate/nitrite reductase genes indicated that nitrate was a critical electron acceptor for sulfur- or metal-oxidizing bacteria in these hydrothermal ecosystems. Our results provided information about the compositions and diversity of the 3 important genes involved in nitrogen fixation and nitrate/nitrite reduction processes in hydrothermal ecosystems and is the first comprehensive genetic repertoire of genes related to potential nitrogen fixation and denitrification processes in various hydrothermal environments.
authors.affiliation: Division of Life Sciences, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China. huiluocao@gmail.com.
authors.forename: Huiluo
authors.initials: H
authors.lastname: Cao
authors.affiliation: Key Laboratory of Marine Biogenetic Resources, The Third Institute of Oceanography, State of Oceanic Administration, Xiamen, China.
authors.forename: Zongze
authors.initials: Z
authors.lastname: Shao
authors.affiliation: State Key Laboratory of Marine Geology, Tongji University, Shanghai, China.
authors.forename: Jiangtao
authors.initials: J
authors.lastname: Li
authors.affiliation: Division of Life Sciences, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China.
authors.forename: Weipeng
authors.initials: W
authors.lastname: Zhang
authors.affiliation: Division of Life Sciences, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China. boqianpy@ust.hk.
authors.forename: Pei-Yuan
authors.initials: PY
authors.lastname: Qian
mesh_terms: D001419:Bacteria / Q000145:classification / Q000201:enzymology / Q000235:genetics / Q000302:isolation & purification; D001426:Bacterial Proteins / Q000235:genetics*; D060086:Hydrothermal Vents / Q000382:microbiology*; D064307:Microbiota; D009565:Nitrate Reductases / Q000235:genetics*; D009586:Nitrogen Fixation / Q000235:genetics; D010802:Phylogeny
chemical_list: D001426:Bacterial Proteins; D009565:Nitrate Reductases
keywords: Hydrothermal chimney sulfide; Middle ocean ridge; napA; nifH; nirS