Abstract

A Gram-positive, rod-shaped, motile, endospore-forming bacterial strain, designated NB22T, was isolated from soil of a lettuce field in Kyonggi province, South Korea, and was characterized by using a polyphasic taxonomic approach. This novel isolate grew optimally at 30-37°C and pH 8-9. It grew in the presence of 0-4% NaCl (optimum, 1-2%). Comparative 16S rRNA gene sequence analysis showed that strain NB22T was closely related to members of the genus Bacillus and fell within a coherent cluster comprising B. siralis 171544T (98.1%) and B. korlensis ZLC-26T (97.3%). The levels of 16S rRNA gene sequence similarity with respect to other Bacillus species with validly published names were less than 96.4%. Strain NB22T had a genomic DNA G+C content of 36.3 mol% and the predominant respiratory quinone was MK-7. The peptidoglycan contained meso-diaminopimelic acid. The major cellular fatty acids were iso-C15:0, anteiso-C15:0, C14:0, and C16:0. These chemotaxonomic results supported the affiliation of strain NB22T to the genus Bacillus, and the low DNA-DNA relatedness values and distinguishing phenotypic characteristics allowed genotypic and phenotypic differentiation of strain NB22T from recognized Bacillus species. On the basis of the evidence presented, strain NB22T is considered to represent a novel species of the genus Bacillus, for which the name Bacillus kyonggiensis sp. nov. is proposed. The type strain is NB22T (=KEMB 5401-267T =JCM 17569T).

• Keywords: taxonomy; 16S rRNA gene; Bacillaceae; Bacillus kyonggiensis