Mesobacillus aurantius sp. nov., isolated from an orange-colored pond near a solar saltern

Abstract

An endospore producing, strict aerobic, Gram-stain-positive, orange-colored colony forming bacterium designated as strain JC1013T was isolated from an orange pond near a solar saltern of Tamil Nadu, India. Phylogenetic analysis of the 16S rRNA gene sequences indicated that strain was affiliated to the family Bacillaceae of the phylum Firmicutes. Strain showed highest 16S rRNA gene sequence identity of 98.7% with Mesobacillus selenatarsenatis SF-1 T and below 98.3% with other members of the genus Mesobacillus. Strain JC1013T produced carotenoid pigments and indole compounds. Major cellular fatty acids of strain JC1013T were iso-C15:0, anteiso-C15:0, C16:0 3-OH, iso-C17:0ω10c and summed feature 4 (iso-C17:1 I/ anteisoB). Polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, two unidentified aminolipids and four unidentified phospholipids. Strain JC1013T constituted m-diaminopimelic acid as diagnostic cell wall amino acids. MK-7 is the predominant menaquinone of strain JC1013T. The genome size of strain JC1013T was 4.6 Mbp and its G + C content was 42.7 mol%. For the affirmation of strain’s taxonomic status, a detailed phylogenomic study was done. Based on the phylogenetic analyses, low ANI (84.6%), AAI (88.5%) values, in-silico DDH ( < 29%) value, morphological, physiological and chemo-taxonomical characteristics, strain JC1013T was clearly distinguished from the nearest phylogenetic neighbor, Mesobacillus selenatarsenatis SF-1T to conclude that it is a new species of the genus Mesobacillus. We propose the name as Mesobacillus aurantius with type strain JC1013T (= NBRC 114146T = KACC 21451 T).