Bacillus ginsengihumi sp. nov., a novel species isolated from soil of a ginseng field in Pocheon province, South Korea

Abstract

A Gram-positive, aerobic or facultative anaerobic, non motile, endospore-forming bacterial strain, designated Gsoil 114T, was isolated from a soil sample of a ginseng field in Pocheon Province (South Korea), and was characterized taxonomically by using a polyphasic approach. It grew well on nutrient agar medium and utilized a limited number of organic substrates as sole carbon sources, including D-xylose and some other carbohydrates, but did not utilize L-amino acids and organic acids. The isolate was positive for oxidase test but negative for catalase, and negative for degradation of macromolecules such as starch, cellulose, xylan, casein, chitin, and DNA. The G+C content of the genomic DNA was 41.8 mol%. The predominant isoprenoid quinone was menaquinone 7 (MK-7). The major fatty acids were anteiso-C15:0 (32.1%), iso-C15:0 (30.5%), and anteiso-C17:0 (30.2%). Comparative 16S rRNA gene sequence analysis showed that strain Gsoil 114T fell within the radiation of the cluster comprising Bacillus species and joined Bacillus shackletonii LMG 18435T with a bootstrap value of 95%. The highest 16S rRNA gene sequence similarities were found with Bacillus shackletonii LMG 18435T (97.6%), Bacillus acidicola DSM 14745T (96.9%), Bacillus sporothermodurans DSM 10599T (96.5%), and Bacillus oleronius DSM 9356T (96.5%). The phylogenetic distance from any other validly described species within the genus Bacillus was less than 96%. DNA-DNA hybridization experiments showed that the DNA-similarities between strain Gsoil 114T and closest phylogenetic neighbors were less than 39%. On the basis of its phenotypic properties and phylogenetic distinctiveness, strain Gsoil 114T (=KCTC 13944T=DSMZ 18134T) was classified in the genus Bacillus as the type strain of a novel species, for which the name Bacillus ginsengihumi sp. nov. is proposed.