Deep-sea methane seep sediments in the Okhotsk Sea sustain diverse and abundant anammox bacteria

摘要: Marginal sea methane seep sediments sustain highly productive chemosynthetic ecosystems and are hotspots of intense biogeochemical cycling. Rich supply stimulates rapid microbial consumption oxygen; these systems thus usually hypoxic to anoxic. This reported evidence for resident nitrogen fixation suggest the presence an anaerobic ammonium-oxidizing (anammox) bacterial community in sediments. To test this hypothesis, we employed detection genes encoding 16S rRNA gene hydrazine dehydrogenase (hzo) investigate structure, abundance distribution anammox Okhotsk Sea. Diverse complements Candidatus Scalindua-related hzo sequences were obtained. Most deep-sea sites harbored abundant with copy numbers as high 10(7)  g(-1) sediment. In general, signatures significantly more deep-water Sediment porewater NO3-, NOx- (i.e. NO3- + NO2-), NOx-/NH4+ sediment silt content correlated situ patterns marker genes, likely because they determine substrate availability geochemistry, respectively. The markers indicate a potentially significant contribution bacteria marine N cycle