Acrocarpospora catenulata sp. nov., a novel actinobacterium isolated from lake sediment

Abstract

A novel actinobacterium, designated strain H8750T, was isolated from sediment sampled at Lugu Lake, southwest PR China and its polyphasic taxonomy was studied. Strain H8750T produced well-developed substrate mycelium, and formed club-shaped and hooked structures borne on the tip of the aerial mycelia. It contained meso-diaminopimelic, glucose, ribose and madurose in whole-cell hydrolysates. The predominant menaquinones were MK-9(H4), MK-9(H2) and MK-9(H6). The phospholipid profile contained diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, hydroxy-phosphatidylethanolamine, unidentified phospholipids and unidentified aminophospholipids. The major fatty acid (>10 %) were cis 9 C17 : 1, iso-C16 : 0 and C15 : 0. The DNA G+C content was 69.7 mol% based on the whole genome sequence. Phylogenetic analysis based on 16S rRNA gene and whole-genome sequences indicated that strain H8750T was closely related to Acrocarpospora macrocephala JCM 10982T (98.0 %), Acrocarpospora pleiomorpha JCM 10983T (97.9 %) and Acrocarpospora phusangensis DSM 45867 T (97.8 %) and formed a monophyletic clade within the genus Acrocarpospora in the phylogenetic trees. The average nucleotide identity and digital DNA–DNA hybridization values between strain H8750T and its closely related Acrocarpospora species were 79.8~87.2 % and 25.9~28.0 %, respectively, which showed that it belonged to a distinct species. Furthermore, the morphological and phenotypic characteristics allowed the isolate to be differentiated from its closely related species. Therefore, it is concluded that strain H8750T can be classified as representing a novel species of the genus Acrocarpospora , for which the name Acrocarpospora catenulata sp. nov. is proposed. The type strain is H8750T (=JCM 34849T=CICC 25116T). Moreover, based on the gene prediction results, strain H8750T may have the genetic potential to synthesize many new secondary metabolites, which further increases its bioactive value.