Marmoricola ginsengisoli sp. nov. and Marmoricola pocheonensis sp. nov. isolated from a ginseng-cultivating field.

Two novel actinobacteria, designated strains Gsoil 097T and Gsoil 818T, isolated from soil of a ginseng field, South Korea, were characterized by a polyphasic approach to clarify their taxonomic positions. They were Gram-reaction-positive, aerobic, non-spore-forming and rod-shaped. Phylogenetic analysis based on 16S rRNA gene sequences indicated that both isolates belong to the genus Marmoricola and were related most closely to Marmicola solisilvae KIS18-7T (99.1 and 98.3 % similarity, respectively), Marmicola terrae JOS5-1T (97.9 and 97.9 %), Marmicola scoriae Sco-D01T (97.8 and 97.1 %) and Marmicola aequoreus SST-45T (97.5 and 97.0 %). The G+C content of the genomic DNA was 68.8 and 70.0 mol%, respectively. Both strains were characterized chemotaxonomically as having ll-2,6-diaminopimelic acid in the cell-wall peptidoglycan, MK-8(H4) as the predominant menaquinone and C17 : 1ω6c, C18 : 1ω9c, C18 : 0 10-methyl and iso-C16 : 0 as major fatty acids. These chemotaxonomic data supported the affiliation of both strains to the genus Marmoricola. However, levels of DNA-DNA relatedness between the two strains and closely related type strains of Marmoricola species were less than 30 %. Moreover, the results of physiological and biochemical tests allowed the phenotypic differentiation of strains Gsoil 097T and Gsoil 818T from other Marmoricola species with validly published names. Therefore, the two isolates represent two novel species, for which the names Marmoricola ginsengisoli sp. nov. (type strain Gsoil 097T = KACC 14267T = DSM 22772T) and Marmoricola pocheonensis sp. nov. (type strain Gsoil 818T = KACC 14275T = DSM 22773T) are proposed.