Marinobacterium alkalitolerans sp. nov., with nitrate reductase and urease activity isolated from green algal mat collected from a solar saltern.

A novel Gram-staining-negative, rod-shaped, 0.6-0.8 µm wide and 2.0-3.0 µm in length, motile bacterium designated strain AK62, was isolated from the green algal mat collected from saltpan, Kakinada, Andhra Pradesh, India. Colonies on ZMA were circular, off-white, shiny, moist, translucent, 1-2 mm in diameter, flat, with an entire margin. The major fatty acids include C, C ω7c, and summed feature 3 (C ω7c and/or C ω6c and/or iso-C 3-OH). Polar lipids include diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, one unidentified aminophospholipid, three unidentified phospholipids, and one unidentified lipid. Polyamine includes Spermidine. The DNA G + C content of the strain AK62 was 58.8 mol%. Phylogenetic analysis based on 16S rRNA gene sequence revealed that strain AK62 was closely related to the type strains Marinobacterium sediminicola, Marinobacterium coralli and Marinobacterium stanieri with a pair-wise sequence similarity of 96.9, 96.6 and 96.6%, respectively, forming a distinct branch within the genus Marinobacterium and clustered with M. stanieri, M. sediminicola, M. coralli and M. maritimum cluster. Strain AK62 shares average nucleotide identity (ANIb, based on BLAST) of 78.44, 76.69, and 76.95% with M. sediminicola CGMCC 1.7287, M. stanieri DSM 7027, and Marinobacterium halophilum Mano11 respectively. Based on the observed phenotypic, chemotaxonomic characteristics, and phylogenetic analysis, strain AK62 is described in this study as a novel species in the genus Marinobacterium, for which the name Marinobacterium alkalitolerans sp. nov. is proposed. The type strain of M. alkalitolerans is AK62 (= MTCC 12102 = JCM 31159 = KCTC 52667).