Actinophytocola xanthii sp. nov., an actinomycete isolated from rhizosphere soil of the plant Xanthium sibiricum.

A novel actinomycete strain, 11-183T, was isolated from the rhizosphere soil of Xanthium sibiricum, which was collected in Tangshan, Hebei, China. A phylogenetic analysis based on 16S rRNA gene sequences showed that strain 11-183T formed a clade within the genus Actinophytocola, with a maximum similarity of 98.44 % to Actinophytocola xinjiangensis QAIII60T, followed by 97.76 % similarity to Actinophytocola sediminis YIM M13705T. The average nucleotide identity and digital DNA-DNA hybridization values differed by 79.24 and 23.4 %, respectively, between strain 11-183T and Actinophytocolaxinjiangensis QAIII60T. Strain 11-183T grew well on N-Z-amine agar, and it produced a scant, white aerial mycelium. The isolate formed pale yellow to brown-black colonies and a dense, non-fragmented, branched substrate mycelium, and produced aerial hyphae on which nodular spore chains formed. Growth was observed at salinities ranging from 0 to 2 %, at pH values ranging from pH 6.5 to 8.0 and at temperatures ranging from 15 to 37 °C. The cell-wall amino acids included meso-diaminopimelic acid. Whole cell hydrolysates contained galactose and glucose. The principal fatty acids were iso-C16 : 0, iso-C16 : 1 H and C17 : 1ω6c. Diphosphatidylglycerol, phosphatidylmonomethylethanolamine and phosphatidylethanolamine were the diagnostic phospholipids. The isoprenoid quinones included MK-9(H4) and MK-10(H4). The G+C content of the genomic DNA was 71.7 mol%. Based on the genotypic and phenotypic data, we conclude that strain 11-183T belongs to a novel species of the genus Actinophytocola. The name proposed for the novel species is Actinophytocola xanthii sp. nov., with the type strain 11-183T (=KCTC 39690T= MCCC 1K02062T).