Abstract: A highly efficient inorganic phosphorus degrading bacterium P4 （Burkholderia cepacia） from the rhizosphere soil of the Parashorea chinensis Wang Hsie. in Nanning Arboretum in Guangxi was used as the research material, the dynamic changes of phosphate-solubilizing ability and pH of phosphate-solubilizing bacteria P4 within 168 h were studied, and the phosphate-solubilizing ability of phosphorus bacteria P4 under different temperature, pH, carbon source, nitrogen source, C/N and NaCl concentration was compared, in order to provide a theoretical basis for the development and application of phosphate-solubilizing microorganisms in microbial fertilizer production. The results showed that, within 168 h of culture, the content of available phosphorus in the culture medium of strain P4 increased first and then decreased, while the pH of the culture medium decreased first and then increased. At 120 h of culture, the content of available phosphorus in the culture medium was the highest, which was 552.87 mg/L, and the pH of the culture medium was the lowest. Correlation analysis showed that there was a highly significant negative correlation between the amount of phosphorus dissolved by strain P4 and the pH of the culture medium. The strain P4 had the best effect of hydrolyzing inorganic phosphorus and grew well when the temperature was 30 ℃, pH was 6.5, carbon source was lactose, nitrogen source was ammonium oxalate, C/N was 20∶1 and NaCl concentration was 0.5%. It had great potential in the follow-up development of microbial fertilizer.

Key words: phosphate-solubilizing bacteria, phosphate-solubilizing ability, rhizosphere, Parashorea chinensis Wang Hsie.