Virgibacillus chiguensis sp. nov., a novel halophilic bacterium isolated from Chigu, a previously commercial saltern located in southern Taiwan

Abstract

A Gram-positive, motile, endospore-forming, irregular rod-shaped (0.7-0.9 x 2.5-5.0 microm), halophilic bacterial strain, NTU-101(T), was isolated from Chigu saltern in southern Taiwan, previously used as a salt production field. The isolate was characterized taxonomically based on biochemical and molecular approaches. It grows optimally at 40 degrees C and in the presence of 5-10 % NaCl. Strain NTU-101(T) has cell-wall peptidoglycan based on meso-diaminopimelic acid and MK-7 as the predominant menaquinone. Major polar lipids are phosphatidylglycerol, diphosphatidylglycerol and phosphatidylethanolamine. Anteiso-C(15 : 0), iso-C(15 : 0) and anteiso-C(17 : 0) are the major fatty acids. The DNA G+C content was 37.3 mol%. Phylogenetic analyses based on 16S rRNA gene sequences showed its affiliation to the genus Virgibacillus. DNA-DNA relatedness values between strain NTU-101(T) and Virgibacillus dokdonensis and Virgibacillus pantothenticus were 17.5 and 21.5 %, respectively. Based on the phenotypic and phylogenetic properties, strain NTU-101(T) (=BCRC 17637(T)=CGMCC 1.6496(T)) was classified as a novel strain of Virgibacillus species, for which the name Virgibacillus chiguensis sp. nov. is proposed.