Aeromicrobium Panaciterrae 和 Microlunatus Ginsengisoli

Two Gram-positive and strictly aerobic bacterium (Aeromicrobium panaciterrae Gsoil 161^T and Microlunatus ginsengisoli Gsoil 633^T) were isolated from soil of a ginseng field in Pocheon Province, South Korea. The novel isolates were characterized using a polyphasic approach in order to determine its taxonomic position. On the basis of 16S rRNA gene sequence similarity, strain Gsoil 161^T was shown to belong to the family Nocardioidaceae and was related to Aeromicrobium marinum (98.0% similarity to the type strain), Aeromicrobium alkaliterrae (97.6%), Aeromicrobium fastidiosum (97.0%) and Aeromicrobium erythreum (96.7%); the sequence similarity with other species within the family was less than 94.4%. And strain Gsoil 633^T was shown to belong to the family Propionibacteriaceae. The closest phylogenetic relative was Microlunatus phosphovorus DSM 19555^T, with 96.1% sequence similarity; the sequence similarity to other members of the family was less than 95.4 %. The two isolates were characterized chemotaxonomically as having LL-2, 6-diaminopimelic acid in the cellwall peptidoglycan, MK-9(H₄) as the predominant menaquinone. According to the fatty acids analysis, the strain Gsoil 161^T was mainly comprised of C₁₆:0, 10-methyl C₁₈:0 (tuberculostearic acid), C₁₆:0 2-OH, 10-methyl C₁₇: 0 and 10-methyl-C₁₆:0, while the strain Gsoil 633^T was anteiso-C₁₅:0, iso-C₁₅:0 and iso-C₁₆:0 as the major fatty acids. The G+C content of the genomic DNA was 65.5mol% (strain Gsoil 161^T) and 69.8 mol% (strain Gsoil 633^T). These morphological and chemotaxonomic properties and phenotypic characteristics supported the affiliation of strain Gsoil 161^T to the genus Aeromicrobium and strain Gsoil 633^T to the genus Microlunatus respectively. However, the results of physiological and biochemical tests enabled the strains Gsoil 161^T and Gsoil 633^T to be differentiated genotypically and phenotypically from currently known Aeromicrobium species and Microlunatus species respectively. Therefore, strain Gsoil 161^T represents a novel species, for which the name Aeromicrobium panaciterrae sp. nov., and strain Gsoil 633^T as Microlunatus ginsengisoli sp. nov. is proposed. The type strain is strain Gsoil 161^T (=KCTC 19131^T=DSM 17939^T=CCUG 52476^T) and Gsoil 633^T (=KCTC 13940^T=DSM 17942^T).