Abstract

A Gram-positive, strictly aerobic, nonmotile, yellowish, coccus- rod-shaped bacterium (designated Gsoil 653T) isolated from ginseng cultivating soil was characterized using a polyphasic approach to clarify its taxonomic position. The strain Gsoil 653T exhibited optimal growth at pH 7.0 on R2A agar medium at 30°C. Phylogenetic analysis based on 16S rRNA gene sequence similarities, indicated that Gsoil 653T belongs to the genus Terrabacter of the family Humibacillus, and was closely related to Terrabacter tumescens DSM 20308T (98.9%), Terrabacter carboxydivorans PY2T (98.9%), Terrabacter terrigena ON10T (98.8%), Terrabacter terrae PPLBT (98.6%), and Terrabacter lapilli LR-26T (98.6%). The DNA G + C content was 70.5 mol%. The major quinone was MK-8(H4). The primary polar lipids were phosphatidylglycerol, diphosphatidylglycerol, phosphatidyl-ethanolamine. The predominant fatty acids were iso-C15:0, iso-C16:0, iso-C14:0, and anteiso-C15:0, as in the case of genus Terrabacter, thereby supporting the categorization of strain Gsoil 653T. However, the DNA-DNA relatedness between Gsoil 653T and closely related strains of Terrabacter species was low at less than 31%. Moreover, strain Gsoil 653T could be both genotypically and phenotypically distinguished from the recognized species of the genus Terrabacter. This isolate, therefore, represents a novel species, for which the name Terrabacter ginsengisoli sp. nov. is proposed with the type strain Gsoil 653T (= KACC 19444T = LMG 30325T).

• Keywords: Terrabacter ginsengisoli; 16S rRNA gene sequence; polyphasic taxonomy