Isolation and identification of phosphate-solubilizing bacteria from mangrove and their phosphate-solubilizing characteristics

The strains of Burkholderia cepacia (NR 113645.1) and Bacillus pumilus (NR 043242.1) were isolated from the mangrove rhizosphere soil of Luoyuan Bay. Their phosphate-decomposing characteristics and dynamic phosphorus-decomposing process were characterized. HPLC results showed that the supernatant of B. cepacia bacteria contained gluconic acid, pyruvate, lactic acid, acetic acid, and succinic acid. The production of these organic acids led to the dissolution of phosphate, resulting in that very little gluconic acid in supernatant and a bad phosphate-dissolving effect of B.pumilus. During the dynamic phosphorus dissolution of B. cepacia, The X-ray diffraction (XRD) characteristic peak intensity of calcium phosphate was dropped and the calcium phosphate particles became smaller or even disappeared with the prolonged treatment time. In contrast, XRD and microscope results showed there were no significant changes in the calcium phosphate's characteristic peak intensity and particle size when the same experiment was performed in B. pumilus. Dissolving phosphate is the key to solving the problem of converting insoluble phosphorus source into bioavailable phosphorus source in compacted soil. © 2020, Editorial Board of China Environmental Science. All right reserved.