Identification, functional annotation, and isolation of phosphorus-solubilizing bacteria in the rhizosphere soil of Swida wilsoniana (Wanger) Sojak

The Swida wilsoniana, a remarkable woody oil tree species of immense ecological and economic significance, encounters limitations in its production within southern China due to the scarcity of available phosphorus (AP) in red soil. In this study, we employed methods encompassing microbial diversity and metagenomic analysis to explore the composition as well as functional disparities among rhizosphere microbial communities associated with S. wilsoniana exhibiting varying growth potentials in red soil. In this study, microbial diversity and metagenomic analysis methods were used to investigate the composition of and functional differences among the rhizosphere microbial communities of S. wilsoniana with different growth potential in red soil. The results showed that the AP content of the rhizosphere soil of dominant trees (DTs) was higher than that of recessive trees (RTs). Three dominant phyla were identified in the rhizosphere soil of S. wilsoniana, including Proteobacteria, Actinobacteria, and Acidobacteria. Fifteen microbial communities involved in 23 metabolic activities were significantly correlated with AP content (P ≤ 0.05). A total of 55 strains of phosphorus-solubilizing bacteria were isolated from the rhizosphere soil of S. wilsoniana. Among these, SwB16 exhibited the highest efficiency in solubilizing phosphorus, with a phosphorus solubilization capacity of up to 347.23 mg·L−1. Pot experiments showed that SwB16 has the potential to promote plant growth and therefore could be used as a biofertilizer for S. wilsoniana.