Photobacterium marinum sp. nov., a marine bacterium isolated from a sediment sample from Palk Bay, India

The novel, cream colored, Gram-staining-negative, rod-shaped, motile bacteria, designated strains AK15T and AK18, were isolated from sediment samples collected from Palk Bay, India. Both strains were positive for arginine dihydrolase, lysine decarboxylase, oxidase, nitrate reduction and methyl red test. The major fatty acids were C16:0, C18:1 ω7c, C16:1 ω7c and/or C16:1 ω6c and/or iso-C15:0 2-OH (summed feature 3). Polar lipids content of strains AK15T and AK18 were found to bephosphatidylethanolamine (PE), two unidentified phospholipids (PL1 and PL2) and three unidentified lipids (L1-L3). The 16S rRNA gene sequence analysis indicated strains AK15T and AK18 as the members of the genus Photobacterium and closely related to the type strain Photobacterium jeanii with pair-wise sequence similarity of 96.7%. DNA–DNA hybridization between strain AK15T and AK18 showed a relatedness of 87%. Based on data from the current polyphasic study, strains AK15T and AK18 are proposed as novel species of the genus Photobacterium, for which the name Photobacterium marinum sp. nov. is proposed. The type strain of Photobacterium marinum is AK15T (=MTCC 11066T = DSM 25368T).