Isolation and phosphate solubilizing capacity determination of rhizosphere phosphate-solubilizing microorganism in King grass

Phosphate-solubilizing microorganisms were isolated from King grass rhizospheres using Mengjinna organic culture media. The phosphate solubilizing capacities were investigated from 41 strains based on phosphate-solubilizing circle and molybdenum blue method. The results indicated that 21 strains had ability to solubilize organic phosphate on Mengjinna organic culture medium and 48 h D/d (diameter of phosphate-dissolving zone/diameter of bacterial clone) value was from 1.3to 7.0; 72 h D/d value was from 1.72 to 5.5; 120 h D/d value was from 1.33 to 4.67. In liquid culture, the available phosphate increment was from 4.11 to 327.1 mg/mL using molybdenum blue method by inorganic phosphatesolubilizing microorganism. Strains 2-6, 2-7-1, 2-9 and 4-4 had higher ability of organic phosphate dissolving, showed great potential for agricultural use in microbiological fertilizer.