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

A mesophilic, straight-rod-shaped, non-flagellated bacterium, designated MEBiC05444 T , 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 T belonged to the family Shewanellaceae , within the class Gammaproteobacteria. Strain MEBiC05444 T showed highest 16S rRNA gene sequence similarity to Parashewanella curva C51 T , followed by [ Shewanella ] irciniae UST040317-058 T and Parashewanella spongiae HJ039 T (98.9 %, 97.2 and 95.7 %, respectively). In the phylogenetic tree based on the 16S rRNA gene sequences, MEBiC05444 T formed a cluster with P. curva C51 T , 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 15 : 0 (19.7 %), summed feature 3 (composed of C 16 : 1  ω7 c and/or C 16 : 1 ω6 c ; 16.1 %) and C 17 : 1 ω8 c (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 T was 40.8 mol%. Based on the results of polyphasic analysis, the strain represents a novel species of the genus Parashewanella , distinct from P. curva C51 T , [ Shewanella ] irciniae UST040317-058 T and P. spongiae HJ039 T for which the name Parashewanellatropica sp. nov. is proposed with type strain MEBiC05444 T (=KCCM 43304 T =JCM 16653 T ).