Oricola nitratireducens sp. nov., a novel nitrate reducing bacterium isolated from marine sediment in East China Sea.

Abstract

A novel strain designated NBU1457T, was isolated from marine sediment sampled on Meishan Island located in the East China Sea. Cells of strain NBU1457T was Gram-negative, facultatively anaerobic, non-motile and ovoid-shaped. Strain NBU1457T grew optimally at 37°C, NaCl concentration of 2.0-3.0% (w/v) and pH 6.5-7.5. Catalase and oxidase activities, urease, nitrate reduction and H2S production were positive. Indole production, methyl red reaction, hydrolysis of starch, gelatin, casein, Tweens 20, 40, 60 and 80 were negative. Comparative analysis of the 16S rRNA gene sequence showed highest similarities to the species with validated name Oricola thermophila MEBiC13590T (98.8%), Oricola cellulosilytica CC-AMH-0T (97.9%) and Oricola indica JL-62T (97.9%). Phylogenetic analyses indicated that strain NBU1457T clustered with the genus Oricola and closely related to strains Oricola thermophila MEBiC13590T, Oricola cellulosilytica CC-AMH-0T and Oricola indica JL-62T. The average nucleotide identity and digital DNA-DNA hybridization values between strain NBU1457T and related species of genus Oricola were well below the threshold limit for prokaryotic species delineation. The DNA G + C content was 63.2%. The major cellular fatty acid was summed feature 8 (C18:1 ω7c and/or C18:1 ω6c). The major polar lipids were phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylmonomethylethanolamine, sulfoquinovosyldiacylglycerol and phosphatidylglycerol. The only respiratory quinone was ubiquinone-10 (Q-10). Combining results of our phenotypic, chemotaxonomic and genotypic data, strain NBU1457T is considered to be a representative in the genus Oricola, which the name Oricola nitratireducens sp. nov. is proposed. The type strain of the new species is NBU1457T (= KCTC 82225T = MCCC 1K04764T).