标题：Biogeochemical Implications of N 2O-Reducing Thermophilic Campylobacteria in Deep-Sea Vent Fields, and the Description of Nitratiruptor labii sp. nov.
摘要：SummaryNitrous oxide (N2O) is a potent greenhouse gas and has significantly increased in the atmosphere. Deep-sea hydrothermal fields are representative environments dominated by mesophilic to thermophilic members of the classCampylobacteriathat possess clade IInosZencoding nitrous oxide reductase. Here, we report a strain HRV44Trepresenting the first thermophilic campylobacterium capable of growth by H2oxidation coupled to N2O reduction. On the basis of physiological and genomic properties, it is proposed that strain HRV44T(=JCM 34002 = DSM 111345) represents a novel species of the genusNitratiruptor,Nitratiruptor labiisp. nov. The comparison of the N2O consumption ability of strain HRV44Twith those of additionalNitratiruptorand other campylobacterial strains revealed the highest level in strain HRV44Tand suggests the N2O-respiring metabolism might be the common physiological trait for the genusNitratiruptor. Our findings provide insights into contributions of thermophilicCampylobacteriato the N2O sink in deep-sea hydrothermal environments.Graphical AbstractDisplay OmittedHighlights•A N2O-reducing thermophile strain HRV44 was isolated from the deep-sea hydrothermal vent•Strain HRV44Tshows strong exogenous N2O reduction at pH 6.0 and 53°C•We propose the nameNitratiruptor labiisp. nov. for strain HRV44T•Members of the genusNitratiruptorpossibly contribute to the capacity of N2O mitigationEarth Sciences; Geology; Geomicrobiology; Microbiology; Biocatalysis
