Solicola agrisoli sp. nov., a novel actinobacterium isolated from agricultural soil in Republic of South Korea.

Abstract

A novel actinobacterial strain, designated PLA-1-18^T, was isolated from agricultural soil in Suwon-si, Republic of Korea. Cells were Gram-stain-positive, coccoid-rod-shaped, motile and obligately aerobic. Growth occurred at 20-30 °C (optimum, 25 °C), pH 5.0-9.0 (optimum, pH 7.0) and in the presence of 0-2% w/v NaCl (optimum, 1% w/v). Strain PLA-1-18^T was catalase- and oxidase-positive. Phylogenetic analysis based on 16S rRNA gene sequences placed PLA-1-18^T within the genus Solicola (family Nocardioidaceae, order Propionibacteriales and class Actinomycetes), with the highest sequence similarity to Solicola gregarius A5X3R13^T (97.6%) and Nocardioides iriomotensis IR27-S3^T (95.8%). The genome comprised 4.6 Mbp with a G+C content of 72.6 mol%. The major fatty acids were 10-methyl C_18:0, 10-methyl C_17:0 and iso-C_16:0 under the experimental conditions used in this study. The predominant polar lipids were phosphatidylglycerol, diphosphatidylglycerol and phosphatidylinositol, along with two unidentified phospholipids, three unidentified amino lipids and one unidentified polar lipid. Menaquinone MK-9(H₄) was the predominant respiratory quinone detected. The genome of strain PLA-1-18^T shared only 73.0% average nucleotide identity and 78 % digital DNA-DNA hybridization with its closest relative, S. gregarius DSM 112953^T, supporting its classification as a distinct novel species. Based on polyphasic taxonomic data, strain PLA-1-18^T represents a novel species of the genus Solicola, for which the name Solicola agrisoli sp. nov. is proposed. The type strain is PLA-1-18^T (=KEMB 23536^T=KCTC 59365^T=TBRC 19594^T).