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

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 degrees C (optimum temperature, 28 degrees 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(H-4). 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-16:1 omega 7c/C-16:1 omega 6c and/or C-16:1 omega 6c/C-16:1 omega 7c (15.0%), iso-C-17:0 (8.6%), C-16:0 (7.0%) and C-17:1 omega 8c (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)).