Indibacter alkaliphilus gen. nov., sp. nov., an alkaliphilic bacterium isolated from a haloalkaline lake

Abstract

A novel Gram-stain-negative, rod-shaped, non-motile bacterium, strain LW1^T, was isolated from a water sample collected at a depth of 3.5 m from Lonar Lake, Buldhana district, Maharashtra, India. The cell suspension was reddish-orange due to the presence of carotenoids. Strain LW1^T was positive for catalase, oxidase, ornithine decarboxylase and lysine decarboxylase and negative for gelatinase, urease and lipase. Fatty acids were dominated by branched-chain fatty acids (>76%), with a high abundance of iso-C_15:0 (48%), anteiso-C_15:0 (7%) and iso-C_17:0 3-OH (11%). Strain LW1T contained MK-4 and MK-7 as the major respiratory quinones and phosphatidylglycerol, phosphatidylcholine and phosphatidylethanolamine as the major phospholipids. A blast sequence similarity search based on 16S rRNA gene sequences indicated that members of the genera Belliella and Aquiflexum were the nearest phylogenetic neighbours with similarities of 91.8-92.3%. Phylogenetic analyses indicated that strain LW1^T formed a deep-rooted lineage distinct from the clades represented by the genera Belliella, Aquiflexum, Cyclobacterium, Echinicola and Algoriphagus. Based on the above-mentioned phenotypic and phylogenetic characteristics, it is proposed that strain LW1^T represents a novel species in a new genus, Indibacter alkaliphilus gen. nov., sp. nov. (type strain LW1^T=KCTC 22604^T=CCUG 57479^T). The genomic DNA G+C content of strain LW1^T is 42.7±1 mol%.