Moritella japonica sp. nov., a novel barophilic bacterium isolated from a Japan Trench sediment.

Strain DSK1 is a novel moderately barophilic bacterium isolated from the Japan Trench at a depth of 6,356 m. Phylogenetic analysis based on 16S ribosomal DNA sequences showed that strain DSK1 represents a separate lineage with the Shewanella barophiles branch and is closely related to Moritella marina. Comparisons of the temperature and pressure range for growth and some biochemical characteristics indicate that strain DSK1 differs from M. marina and Shewanella barophilic species. Furthermore, strain DSK1 displays a low level of DNA similarity to the Moritella and Shewanella type strains; however this isolate characteristically produces DHA (22:6) as a membrane fatty acids, and the fatty acid profile of this strain is similar to that of M. marina. Because of these differences, strain DSK1 appears to represent a novel deep-sea Moritella species. The name Moritella japonica is proposed. The type strain is JCM 10249.