Abstract: ：Phosphorus is one of the important elements for plant growth. Plants cannot absorb enough phosphorus when a large amount of phosphorus in the soil exists in the form of insoluble state. To increase the utilization efficiency of phosphorus in saline-alkali, phosphate solubilizing bacteria were isolated from saline-alkali soil in Binhai New Area of Tianjin. Strain LQH-7, producing distinct soluble phosphorus circle with SPI 2.86, was isolated in inorganic phosphorus solid plate. Morphology, physiological-biochemical index and phylogenetic analysis based on 16S rDNA gene sequences showed that strain LQH-7 belonged to Pseudomonas veronii, exhibiting the highest sequence similarity with P. veronii CIP 104663（99.65%）. In inorganic phosphorus medium,under the fermentation conditions in which the initial pH was 8.0, NaCl content was 0.5%, temperature was 30 ℃ and fermentation time was 60 h, pH of strain LQH-7 fermentation broth reached 4.30 and the phosphate-solubilizing quantity reached its highest value, 850.1 mg/L, suggesting that LQH-7 is a potent candidate for bioremediation of saline-alkali soil.

Key words: phosphate solubilizing bacteria, Pseudomonas veronii, identification of bacteria, phosphate solubilizing ability