sp. nov., a mesophilic bacterium isolated from a marine sponge from Chuuk lagoon, Federated States of Micronesia, and emended description of the genus .

A mesophilic, straight-rod-shaped, non-flagellated bacterium, designated MEBiC05444, was isolated from a marine sponge collected from Chuuk lagoon, Federated States of Micronesia. The strain was Gram-negative, catalase- and oxidase-positive, and facultative anaerobic. The isolate aerobically grew at 8-38 °C (optimum, 24-32 °C), pH 4.0-10.0 (pH 7.0-7.5) with an absolute requirement for Na up to 6 % (w/v) NaCl (2 %). Phylogenetic analyses based on 16S rRNA gene sequences revealed that MEBiC05444 belonged to the family , within the class Gammaproteobacteria. Strain MEBiC05444 showed highest 16S rRNA gene sequence similarity to C51, followed by [] UST040317-058 and HJ039 (98.9 %, 97.2 and 95.7 %, respectively). In the phylogenetic tree based on the 16S rRNA gene sequences, MEBiC05444 formed a cluster with C51, but the average nucleotide identity value between the two strains was 82 %, thus confirming their separation at species level. The major fatty acids were iso-C (19.7 %), summed feature 3 (composed of C ω7 and/or Cω6; 16.1 %) and Cω8 (10.2 %). The only detected respiratory quinone was ubiquinone Q-8. The major polar lipids were phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, three unidentified aminoglycolipids, two unidentified glycolipids, an unidentified aminoglycophospholipid and an unidentified lipid. The genomic DNA G+C content of strain MEBiC05444 was 40.8 mol%. Based on the results of polyphasic analysis, the strain represents a novel species of the genus , distinct from C51, [] UST040317-058 and HJ039 for which the name sp. nov. is proposed with type strain MEBiC05444 (=KCCM 43304=JCM 16653).