Isolation and Characterization of a Novel Bacterium, Bacillus subtilis HR-1019, with Insoluble Phosphates Solubilizing Activity

The objective of this study was to develop a mineral phosphate-solubilizing bacterium as a biofertilizer. A mineral phosphate-solubilizing bacterium HR-1019 was isolated from cultivated soils. It was identified as Bacillus subtilis by 16S rDNA analysis. The phosphate-solubilizing activities of the HR-1019 strain against three types of insoluble phosphate, hydroxyapatite, tri-calcium phosphate, and aluminum phosphate were quantitatively determined. When 5% of glucose concentration was used as a carbon source, the strain showed marked mineral phosphate-solubilizing activity. Mineral phosphate solubilization was directly related to pH drop in the culture solution of the strain. The pathogenic activity and antifungal effects of the HR-1019 strain were measured inclear zones formed in PDA media.