Rhodomicrobium lacus sp. nov., an alkalitolerent bacterium isolated from Umiam lake, Shillong, India

A Gram-stain-negative, motile, alkali-tolerant, swollen-rod shaped, reddish brown coloured, phototrophic bacterium designated as strain JA980 T , was isolated from freshwater sampled at Umiam lake, Shillong, India. Strain JA980 T grew well up to pH 9.0. Respiratory quinones were ubiquinone 10 and rhodoquinone 10. The major fatty acid was C 18: 1 ω7 c /C 18:1 ω6c with minor amounts of C 18:0 , C 16:0 , C 18:0 3-OH and C 16:0 3-OH. Strain JA980 T contained bacteriochlorophyll- a and carotenoids of the spirilloxanthin series. The polar lipids of strain JA980 T comprised phosphatidylethanolamine, phosphatidylcholine, diphosphatidylglycerol, an unidentified phospholipid, unidentified amino lipids (AL1,3,4,5) and an unidentified lipid (L1). Strain JA980 T had the highest (99.57 %) 16S rRNA gene sequence similarity to the type strains of Rhodomicrobium vannielii ATCC17100 T and Rhodomicrobium udaipurense JA643 T . The genome of strain JA980 T was 3.88 Mbp with a DNA G+C content of 62.4 mol%. Based on the results of phylogenetic analyses, low in silico DNA-DNA hybridization values (33 %), low (87 %) average nucleotide identity results, chemotaxonomic characteristics and differential physiological properties, strain JA980 T could not be classified into either of the two recognized species of the genus Rhodomicrobium , suggesting that it represents a novel species, for which the name Rhodomicrobium lacus sp. nov. is proposed. The type strain is JA980 T (=KCTC 15697 T = MCC 3714 T = NBRC 113803 T ).