Actinokineospora xionganensis sp. nov., a filamentous actinomycete isolated from the lakeside soil of Baiyangdian

Abstract

A novel actinomycete, strain HBU206404^T, belonging to the genus Actinokineospora, was isolated from the lakeside soil of Baiyangdian, in China. Cells grew at 9–37 °C (optimum temperature, 28 °C) and pH 6–9 (optimum, pH 7). Meso-diaminopimelic acid was the diagnostic diamino acid of the cell-wall peptidoglycan, and sugars present in whole-cell hydrolysates were arabinose, mannose, glucose and galactose. The predominant menaquinone was MK-9(H₄). The predominant cellular fatty acids (> 5%) of the strain HBU206404^T were iso-C_16:0 (21.5%), iso-C_15:0 (20.3%), C_16:1ω7c/C_16:1ω6c and/or C_16:1ω6c/C_16:1ω7c (15.0%), iso-C_17:0 (8.6%), C_16:0 (7.0%) and C_17:1ω8c (6.9%). The major polar lipids of the strain HBU206404^T were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, phosphatidylglycerol, six unknown aminolipids, two unknown aminolipids and an unidentified lipid. The 16S rRNA gene sequence analysis indicated that the strain HBU206404^T was most closely related to Actinokineospora alba KCTC 19294^T (99.58%), but whole-genome comparisons, using average nucleotide identity (ANI) value (91.77%) and digital DNA-DNA hybridization (dDDH) value (60%), confirmed low genome relatedness. Nitrogen metabolism pathway was found in the genome of strain HBU206404^T which haboured nitrate reductase and nitrite reductase. Other phenotypic characteristics, such as ability to hydrolyze substances, enzyme activity, acid production from carbon source, etc., could also distinguish strain HBU206404^T from Actinokineospora alba KCTC 19294^T. On the basis of genetic and phenotypic evidence, strain HBU206404^T represents a novel species of the genus Actinokineospora, for which the name Actinokineospora xionganensis sp. nov. is proposed. The type strain is HBU206404^T (= MCCC 1K04412^T = KCTC 49404^T).