Ammonicoccus luteus sp. nov., a novel actinobacterium isolated from the intestine of Argyrosomus argentatus
摘要
Strain GXG 6511T, a Gram-stain-positive, facultatively anaerobic, non-motile, non-spore-forming actinobacterium with coccoid cells, was isolated from the intestine of Argyrosomus argentatus collected in Beihai, Guangxi Zhuang Autonomous Region, China. Under anaerobic conditions, strain GXG 6511T showed weaker growth than under aerobic conditions. After incubation on R2A medium at 28 °C for 72 h under aerobic conditions, colonies of strain GXG 6511T were observed to be yellow, circular, rough, opaque, convex and 1–2 mm in diameter. Chemotaxonomic analysis revealed that MK-9(H4) was the major menaquinone, while anteiso-C15:0, iso-C14:0 and iso-C15:0 were identified as dominant fatty acids. Analysis of the whole-cell hydrolysate confirmed the presence of LL-diaminopimelic acid. Polar lipids profiling showed the presence of diphosphatidylglycerol, phosphatidylglycerol, and two unidentified glycolipids. The genomic DNA G + C content of the strain was determined to be 67.5%. Phylogenetic analysis based on 16 S rRNA gene sequences showed that strain GXG 6511T formed a distinct lineage and was most closely related to Ammonicoccus fulvus ZF39T (97.2%). Further genomic analysis revealed that strain GXG 6511T shares an average nucleotide identity (ANI) value of 76.6% with A. fulvus ZF39T. In addition, the digital DNA–DNA hybridization (dDDH), percentage of conserved proteins (POCP), and amino acid identity (AAI) values between the two strains were 20.6%, 77.1%, and 74.9%, respectively. On the basis of the combined phenotypic, chemotaxonomic, phylogenetic and genomic evidence, strain GXG 6511T is considered to represent a novel species of the genus Ammonicoccus, for which the name Ammonicoccus luteus sp. nov. is proposed. The type strain is GXG 6511T (= MCCC 1K09574T = KCTC 59468T). The GenBank accession numbers for the 16 S rRNA gene sequence and whole-genome shotgun assembly are PQ225952.1 and NZ_JBNZCI000000000.1, respectively.