sp. nov., an agar-digesting marine bacterium isolated from coastal seawater in Daya Bay (Guangdong, China).

A Gram-strain-negative, facultatively anaerobic, motile, rod-shaped and flagellated marine bacterium, designated SM6, was isolated from surface seawater collected in Daya Bay (Guangdong, China). Phylogenetic analysis based on 16S rRNA gene sequences, multilocus sequence analysis, phylogenomic analysis of single-copy gene families and whole genome data showed that strain SM6 belonged to the genus . The closest phylogenetic relatives of SM6 were MSSRF60 (97.38 % 16S rRNA gene sequence pairwise similarity), R-40492 (97.27 %), ATCC 35048 (97.21 %) and LC2-047 (97.3 %). Growth of strain SM6 occurred at 10-45 °C (optimum 30 °C), at pH 6.0-9.0 (optimum 6.0) and in the presence of 0-10 % (w/v) NaCl (optimum 3-8 %). The predominant fatty acids (>10 %) were summed feature 3 (C 7 or/and C 6), C and summed feature 8 (C 7 or/and C 6). The DNA G+C content of the assembled genomic sequences was 47.37 % for strain SM6. Average nucleotide identity values between SM6 and its reference species were lower than the threshold for species delineation (95-96 %); DNA-DNA hybridization further showed that the strains shared less than 70 % similarity. On the basis of evidence from the present polyphasic study, strain SM6 is considered to represent a novel species of the genus , for which the name sp. nov. is proposed. The type strain is SM6 (=KCTC 82076=MCCC 1K04327 ).