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 LW1T, 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 LW1T 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-C15 : 0 (48 %), anteiso-C15 : 0 (7 %) and iso-C17 : 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 LW1T 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 LW1T represents a novel species in a new genus, Indibacter alkaliphilus gen. nov., sp. nov. (type strain LW1T=KCTC 22604T=CCUG 57479T). The genomic DNA G+C content of strain LW1T is 42.7±1 mol%.