Bacillus luteolus sp. nov., a halotolerant bacterium isolated from a salt field

Abstract

A novel Gram-stain-positive, motile, strictly aerobic bacterium, designated YIM 93174(T), was isolated from a salt field in Korea. Cells of this strain were rod-shaped and formed pale tangerine colonies and grew at pH 6.0-8.0 (optimal growth at pH 7.0), at 15-45 °C (optimum 28-37 °C) and at salinities of 0-10 % (w/v) NaCl (optimum 0-2 % NaCl). Some phenotypic characters allowed differentiation of strain YIM 93174(T) from its nearest phylogenetic relatives. Comparative 16S rRNA gene sequence analysis showed that strain YIM 93174(T) belongs to the genus Bacillus, exhibiting the highest level of sequence similarity with the type strain of Bacillus humi (95.7 %), followed by those of Bacillus alkalitelluris (94.9 %) and Bacillus litoralis (94.5 %). The major fatty acids were iso-C(15 : 0), anteiso-C(15 : 0) and iso-C(16 : 0). The cell-wall peptidoglycan was of the A1γ type, containing meso-diaminopimelic acid as the diagnostic diamino acid. The genomic DNA G+C content was 36.9 mol% and the predominant respiratory quinone was MK-7. The major polar lipids of strain YIM 93174(T) were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol, phosphatidylinositol mannoside and two unknown phospholipids. On the basis of the evidence from this polyphasic study, strain YIM 93174(T) represents a novel species of the genus Bacillus, for which the name Bacillus luteolus sp. nov. is proposed, with YIM 93174(T) ( = DSM 22388(T) = KCTC 13210(T) = CCTCC AA 208068(T)) as the type strain.