Nitrincola alkalisediminis sp. nov., an alkaliphilic bacterium isolated from an alkaline lake

Two Gram-stain-negative, aerobic, alkaliphilic bacteria (strains MEB087T and MEB142) were isolated from sediment and water samples, respectively, collected from the alkaline Lonar Lake in Maharashtra, India. Strains MEB087T and MEB142 shared 99.8 % 16S rRNA gene sequence similarity and were 85 % related on the basis of DNA-DNA hybridization. The 16S rRNA gene sequences of both strains showed close relationship with the genus Nitrincola, and their closest neighbour was Nitrincola lacisaponensis 4CAT with 97.7 % sequence similarity. MEB087T and MEB142 exhibited only 45 % and 54 % DNA-DNA relatedness, respectively, with Nitrincola lacisaponensis DSM 16316T. Both strains were asporogenous, short, non-motile rods capable of utilizing a limited range of organic acids as sole carbon and energy sources. They were oxidase- and catalase-positive, able to reduce nitrate and nitrite; but unable to degrade DNA, urea, gelatin, casein or starch. They grew optimally at pH 9.5 (tolerating up to pH 11) and could withstand up to 0.6 M NaCl. The predominant cellular fatty acids were summed feature 8 comprising C18 : 1ω7c/C18 : 1ω6c (47-49 %) followed by summed feature 3 comprising C16 : 1ω7c/C16 : 1ω6c (28-32 %). The predominant polar lipids were diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylcholine. The DNA G+C content was 49.3-49.7 mol%. On the basis of the phylogenetic analysis and chemotaxonomic characteristics, strains MEB087T and MEB142 represent a novel species in the genus Nitrincola, for which the name Nitrincola alkalisediminis sp. nov. is proposed. The type strain is MEB087T ( = KCTC 42948T = JCM 19317T) with MEB142 ( = KCTC 42949 = JCM 19318) as an additional strain.