Actinomadura Litoris Sp. Nov., An Actinobacterium Isolated From Sandy Soil In Sanya

A novel actinobacterium, designated strain NEAU-AAG5(T), 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-AAG5(T) belongs to the genus Actinomadura and shared highest sequence similarity with Actinomadura macra NBRC 14102(T) (98.8 %). Strain NEAU-AAG5(T) grows at 20-40 degrees C (optimum, 28 degrees C), pH 6-10 (optimum, pH 7) and has NaCl tolerance of 0-3%. The menaquinones were identified as MK-9(H-4) (4.2%), MK-9(H-6) (49.2 %) and MK-9(H-8) (46.5%). The major fatty acids were C-16:0 (31.4%), 10-methyl C-18:0 (21.3%) and C-18:1 omega 9c (15.7 %). The polar lipids were diphosphatidylglycerol, phosphatidylinositol, phosphatidylinositolmannoside, phosphatidylglycerol and phosphoglycolipid. The genomic DNA G+C content of strain NEAU-AAG5(T) based on whole genome sequences was 72.8mol%. Digital DNA-DNA hybridization between strain NEAU-AAG5(T) and its closest phylogenetic neighbour, A. macra NBRC 14102(T), resulted in similarity value of 28.0 % (<70%). Additionally, the average nucleotide identity was 84.2 % for A. macra NBRC 14102(T). On the basis of phenotypic, genotypic and phylogenetic data, strain NEAU-AAG5(T) 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-AAG5(T) (=JCM 33456(T)=CCTCC AA 2019043(T)).