Sinomonas jingmaiensis sp. nov., a potentially plant growth-promoting actinobacterium isolated from the rhizosphere soil of Pu-erh tea in Jingmai Mountain

Abstract Strain P47F4, a potentially plant growth-promoting actinobacterium isolated from the rhizosphere soil of Pu-erh tea plants in the Jingmai Pu-erh Tea District, Yunnan Province, China. The bacterium is Gram-positive, rod-shaped, and non-motile. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain P47F4 belongs to the genus Sinomonas, with its closest relative being Sinomonas humi MUSC 117T (98.49%). The major fatty acids(> 10.0% of the total) were anteiso-C15:0 (39.99%) and C20:0 (10.26%). The predominant respiratory quinones detected were MK-9(H₂) and MK-8(H₂). The polar lipid profile consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, and glycolipids. Peptidoglycan analysis revealed the presence of glutamic acid, lysine, aspartic acid, serine, alanine, and glycine. The genome of strain P47F4 is 4.44 Mbp in size, with a G + C content of 66.82%. The average nucleotide identity (ANI) value of 79.70% to the most related reference strains, which is lower than the species delineation threshold of 95%. The digital DNA-DNA hybridization (dDDH) of the isolate resulted in a relatedness value of 22.90% with its closest neighbour.Based on these results, strain P47F4 represents a novel species within genus Sinomonas, for which the name Sinomonas jingmaiensis sp. nov. is proposed. The type strain is P47F4T (= CCTCC AB 2025067T = MCCC 1K09929T = KCTC 59560T).