sp. nov., a novel piezophile isolated from hadopelagic water of the Mariana Trench and reclassification of as a later heterotypic synonym of .

A novel marine Gram-stain-negative, non-motile, aerobic and rod-shaped bacterium, designated as strain MT-229, was isolated from the deep seawater in the Mariana Trench and characterized phylogenetically and phenotypically. Bacterial optimal growth occurred at 30 °C (ranging 10-40 °C), pH 6 (ranging 3-11) and with 11 % (w/v) NaCl (ranging 0-17 %). Strain MT-229 was a piezophile, growing optimally at 20 MPa (range 0.1-70 MPa). The nearest phylogenetic neighbours were CGMCC 1.2174 and JCM 17757 with 16S rRNA gene similarity of 98.7 %. The sole respiratory quinone was menaquinone-6 (MK-6). The major polar lipids were phosphatidylethanolamine (PE), two unidentified aminolipids (AL) and ten unidentified lipids. The major fatty acids of strain MT-229 were iso-C, iso-C 3-OH and iso-C G. The G+C content of the genomic DNA was 45.6 mol%. The combined genotypic and phenotypic data indicated that strain MT-229 represents a novel species of the genus , for which the name sp. nov. is proposed, with the type strain MT-229 (=DSM 109894=MCCC 1K04201). In addition, the whole-genome-based comparisons revealed that the type strains of and belong to a single species. It is, therefore, proposed that be recognized as a heterotypic synonym of .