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

A novel actinobacterium, designated strain H8750(T), was isolated from sediment sampled at Lugu Lake, southwest PR China and its polyphasic taxonomy was studied. Strain H8750(T) 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(H-4), MK-9(H-2) and MK-9(H-6). The phospholipid profile contained diphosphatidylglycerol, phosphatidylglycerol. phosphatidylethanolamine, hydroxy-phosphatidylethanolamine, unidentified phospholipids and unidentified aminophospholipids. The major fatty acid (>10 %) were cis 9C(17:1), iso-C-16(:0) and C-15:0. The DNA G+C content was 69.7mol% based on the whole genome sequence. Phylogenetic analysis based on 165 rRNA gene and whole-genome sequences indicated that strain H8750(T) was closely related to Acrocarpospora macrocephala JCM 10982(T) (98.0 %), Acrocarpospora pleiomorpha JCM 10983(T) (97.9 %) and Acrocarpospora phusangensis DSM 45867(T) (97.8 %) and formed a monophyletic Glade within the genus Acrocarpospora in the phylogenetic trees. The average nucleotide identity and digital DNA-DNA hybridization values between strain H8750(T) and its closely related Acrocarpospora species were 79.8 similar to 87.2% and 25.9 similar to 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 H8750(T) 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 H8750(T) (=JCM 34849(T) =CICC 25116(T)). Moreover, based on the gene prediction results, strain H8750(T) may have the genetic potential to synthesize many new secondary metabolites, which further increases its bioactive value.

Automated summary

A novel actinobacterium, strain H8750(T), was isolated and studied, showing distinct morphological and genetic characteristics. It was closely related to Acrocarpospora macrocephala, Acrocarpospora pleiomorpha, and Acrocarpospora phusangensis, but formed a distinct species. Strain H8750(T) was identified as a new species, Acrocarpospora catenulata sp. nov.