Actinomadura litoris sp. nov., an actinobacterium isolated from sandy soil in Sanya

Abstract

A novel actinobacterium, designated strain NEAU-AAG5T, was isolated from sandy soil collected from Niuwang island in Sanya, Hainan Province, PR China. The taxonomic position of the strain was investigated using a polyphasic approach. On the basis of 16S rRNA gene sequence analysis, strain NEAU-AAG5T belongs to the genus Actinomadura and shared highest sequence similarity with Actinomadura macra NBRC 14102T (98.8 %). Strain NEAU-AAG5T grows at 20–40 °C (optimum, 28 °C), pH 6–10 (optimum, pH 7) and has NaCl tolerance of 0–3 %. The menaquinones were identified as MK-9(H4) (4.2 %), MK-9(H6) (49.2 %) and MK-9(H8) (46.5 %). The major fatty acids were C16 : 0 (31.4 %), 10-methyl C18 : 0 (21.3 %) and C18 : 1  ω9c (15.7 %). The polar lipids were diphosphatidylglycerol, phosphatidylinositol, phosphatidylinositolmannoside, phosphatidylglycerol and phosphoglycolipid. The genomic DNA G+C content of strain NEAU-AAG5T based on whole genome sequences was 72.8 mol%. Digital DNA–DNA hybridization between strain NEAU-AAG5T and its closest phylogenetic neighbour, A. macra NBRC 14102T, resulted in similarity value of 28.0 % (<70 %). Additionally, the average nucleotide identity was 84.2 % for A. macra NBRC 14102T. On the basis of phenotypic, genotypic and phylogenetic data, strain NEAU-AAG5T can be characterized to represent a novel species of the genus Actinomadura , for which the name Actinomadura litoris sp. nov. is proposed. The type strain is NEAU-AAG5T (=JCM 33456T=CCTCC AA 2019043T).