Brachybacterium phenoliresistens sp. nov., isolated from oil-contaminated coastal sand

Abstract

A coccoid- to ovoid-shaped, Gram-positive, non-motile bacterial strain, designated phenol-AT, was isolated from an oil-contaminated coastal sand sample collected from Pingtung County, southern Taiwan, and characterized by use of a polyphasic approach. Phylogenetic analyses based on 16S rRNA gene sequences showed that the novel strain formed a monophyletic branch at the periphery of the evolutionary radiation occupied by the genus Brachybacterium in the family Dermabacteraceae, class Actinobacteria. The closest neighbours were Brachybacterium rhamnosum LMG 19848T (96.9 % 16S rRNA gene sequence similarity), Brachybacterium nesterenkovii DSM 9573T (97.0 %) and Brachybacterium muris C3H-21T (96.3 %). The peptidoglycan type of strain phenol-AT was variation A4γ with meso-diaminopimelic acid as the diagnostic cell-wall diamino acid. The isolate contained MK-7 as the major component of the quinone system. The polar lipid profile consisted of diphosphatidylglycerol, phosphatidylglycerol, and unidentified phospholipids and glycolipids. The predominant fatty acid was anteiso-C15 : 0 (59.5 %); significant amounts of iso-C16 : 0 (9.4 %), iso-C14 : 0 (9.5 %) and anteiso-C17 : 0 (10.8 %) were also present. The isolate was also distinguished from recognized members of the genus Brachybacterium on the basis of several phenotypic and biochemical characteristics. It is evident from the genotypic, chemotaxonomic and phenotypic data that isolate phenol-AT represents a novel species of the genus Brachybacterium, for which the name Brachybacterium phenoliresistens sp. nov. is proposed. The type strain is phenol-AT (=LMG 23707T=BCRC 17589T).