Salibacterium nitratireducens sp. nov., a haloalkalitolerant bacterium isolated from a water sample from Sambhar salt lake, India.

Abstract

A strictly aerobic, haloalkali-tolerant, Gram-stain-positive, non-motile, rod-shaped bacterium, designated strain SMB4T, was isolated from a water sample collected from Sambhar salt lake, Rajasthan, India. Growth occurred at 25-50 °C, 4-12 % (w/v) NaCl and pH of 5-9. Strain SMB4T was positive for β-galactosidase, oxidase, catalase and urease activities. The fatty acids were dominated by branched forms of fatty acids with iso- and anteiso-saturated fatty acids, with a high abundance of anteiso-C15 : 0, anteiso-C17 : 0 and C18 : 0. The cell-wall peptidoglycan of strain SMB4T contained meso-diaminopimelic acid, while the polar lipids included diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, one unidentified phospholipid and three unidentified lipids. The DNA G+C content of strain SMB4T was 49.1 mol%. A blast sequence similarity search based on 16S rRNA gene sequence indicated that Salibacterium halochares, Salibacterium halotolerans and Salibacterium qingdaonense were the nearest phylogenetic neighbours, with a pair-wise sequence similarities of 98.4, 98.2 and 97.0 % respectively. Phylogenetic analysis showed that strain SMB4T was clustered with S. halochares and together clustered with S. halotolerans and S. qingdaonense. DNA-DNA hybridization of strain SMB4T with S. halochares DSM 21373T, S. halotolerans S7T and S. quigdaonense DSM 21621T showed a relatedness values of only 39.8, 26.3 and 42.8 %, respectively. Based on its phenotypic characteristics and on phylogenetic inference, strain SMB4T represents a novel species of the genus Salibacterium, for which the name Salibacterium nitratireducens sp. nov. is proposed. The type strain is SMB4T (=MTCC 12633T=KCTC 33876T=JCM 32187T).