Isolation and characterization of phosphate solubilizing bacteria from Chinese cabbage

Phosphate solubilizing bacteria (PSB) were isolated from the rhizosphere of Chinese cabbage and screened on the basis of their solubilization of inorganic tricalcium phosphate in liquid cultures. Ten strains that had higher solubilization potential were selected, and they also produced indole%3%acetic acid, 1% aminocyclopropane%1%carboxylate (ACC) deaminase, an d siderophores. The strains were identified to be members of Pseudomonas , by 16S rDNA sequence analysis. Seed bacterization with PSB strains increased the root elongation and biomass of Chinese cabbage in seedling culture, although they had no effect on phosphorus uptake of plants. The plant growth promotion by PSB in this study could be due to the production of phytohormones or mechanisms other than phosphate solubilization, since they had no effect on P nutrition. Key Words Phosphate solubilizing bacteria, Pseudomonas , 1%aminocyclopropane%1%carboxylate, indole%3%aceti c acid.