Microbispora maris sp. nov., a novel actinobacterium isolated from the gill of the leopard coral grouper (Plectropomus leopardus)

A novel actinomycete, designated strain ZYX-F-249^T, was isolated from the gill of a leopard coral grouper in Yongxing Island, Hainan Province, China. Based on 16S rRNA gene sequence analysis, strain ZYX-F-249^T belonged to the genus <i>Microbispora</i>, with high similarities to <i>Microbispora rosea</i> ATCC 12950^T (98.7 %), <i>Microbispora hainanensis</i> 211020^T (98.5 %), <i>Microbispora clausenae</i> CLES2^T (98.4 %), <i>Microbispora bryophytorum</i> NEAU-TX2-2^T (98.1 %) and <i>Microbispora oryzae</i>RL4-1S^T (98.0 %). Phylogenetic analysis of the 16S rRNA gene sequence of strain ZYX-F-249^T showed that the strain formed a stable subclade with <i>Microbispora rosea</i> ATCC 12950^T in the genus <i>Microbispora</i>. The cell wall of the novel isolate contained <i>meso</i>-diaminopimelic acid, while whole-cell sugars were madurose, glucose and ribose. The predominant menaquinones were MK-9(H₆), MK-9(H₄), MK-9(H₂) and MK-9(H₀). The characteristic phospholipids (PLs) were phosphatidylethanolamine, phosphatidylinositol, diphosphatidylglycerol, phosphatidylmethylethanolamine, phosphatidylinositol mannoside, glycophospholipids and an unknown PL. The major cellular fatty acids (>10%) were <i>iso</i>-C_{16 : 0} and <i>iso</i>-C_{18 : 0}. Genome sequencing showed a DNA G+C content of 71.6%. The low average nucleotide identity, digital DNA-DNA hybridization and average amino acid identity values demonstrated that strain ZYX-F-249^T could be readily distinguished from closely related species. Based on data from these phylogenetic, chemotaxonomic and physiological characteristics, strain ZYX-F-249^T represents a novel species of the genus <i>Microbispora</i>, for which the name <i>Microbispora maris</i> sp. nov. is proposed. The type strain is ZYX-F-249^T (=CCTCC AA 2023030^T =JCM 36778^T).