Phycicoccus mangrovi sp. nov., a novel endophytic actinobacterium isolated from bark of Sonneratia apetala

Two novel strains KQZ13P-1(T) and MAQZI3P-2 were isolated from bark of Sonneratia apetala collected from Maowei sea Mangrove Nature Reserve in Guangxi Zhuang Autonomous Region, China. Two strains were Gram-positive, aerobic, non-spore-forming, no diffusion pigment actinobacterial strains and investigated by a polyphasic approach to determine their taxonomic position. The average nucleotide identity (ANI) value and the digital DNA-DNA hybridization (dDDH) value between the two strains were 99.9% and 99.7%, respectively, suggesting that they belonged to the same species. The ANI and dDDH values between strain KQZ13P-1(T) and five Phycicoccus species were 74.4-95.3% and 20.1-61.5%, respectively. Phylogenetic analyses based on 16S rRNA gene sequences showed that the two strains were member of the genus Phycicoccus and were closely related to P. jejuensis NRRL B-24460(T) (99.2% sequence similarity), followed by P. ginsengisoli DCY87(T) (97.5-97.6%). Moreover, based on 88 core genes, the phylogenomic tree indicated that the two strains clustered with P. jejuensis NRRL 6-24460(T). The cell-wall peptidoglycan of both strains contained meso-diaminopimelic acid. The major fatty acids in two strains were C-17:1 omega 8c, iso-C-15:0 and iso-C-16:0. The major polar lipids included diphosphatidylglycerol (DPG), phosphatidylethanolamine (PE) and phosphatidylinositol (PI). Based on phylogenetic, phenotypic and chemotaxonomic analysis, strains KQZ13P-1(T) and MAQZI3P-2 represent a novel species of the genus Phycicoccus, for which the name Phycicoccus mangrovi sp. nov. is proposed. The type strain is KQZ13P-1(T) (=CGMCC 1.18973(T)= JCM 34556(T)). (C) 2021 Elsevier GmbH. All rights reserved.

Automated summary

Two novel bacterial strains belonging to the genus Phycicoccus were isolated from the bark of Sonneratia apetala in Maowei sea Mangrove Nature Reserve. Through polyphasic and phylogenetic analysis, they were identified as a new species named Phycicoccus mangrovi sp. nov.