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

Two Gram-stain-negative, aerobic, alkaliphilic bacteria (strains MEB087(T) and MEB142) were isolated from sediment and water samples, respectively, collected from the alkaline Lonar Lake in Maharashtra, India. Strains MEB087(T) 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 4CA(T) with 97.7 % sequence similarity. MEB087(T) and MEB142 exhibited only 45 % and 54 % DNA-DNA relatedness, respectively, with Nitrincola lacisaponensis DSM 16316(T). 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 C-18 : 1 omega 7c/C-18 : 1 omega 6c (47-49 %) followed by summed feature 3 comprising C-16 : 1 omega 7c/C-16 : 1 omega 6c (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 MEB087(T) and MEB142 represent a novel species in the genus Nitrincola, for which the name Nitrincola alkalisediminis sp. nov. is proposed. The type strain is MEB087(T) (=KCTC 42948(T)=JCM 19317(T)) with MEB142 (=KCTC 42949=JCM 19318) as an additional strain.