Efficiency of sulphur oxidizing bacteria to solubilize phosphorus from rock phosphoate of Hazara, Pakistan

The information about sulphur oxidising bacteria from rock phosphate mine area Hazara Pakistan is still unknown. This study was conducted to isolate sulphur oxidising bacteria from rock phosphate mine area Hazara Pakistan. Bacterial strains, specifically Sulphur oxidizing bacteria (SOB), have the ability to oxidize elemental sulphur (S°) and overcome S compounds to release sulphuric acid. Sulphuric acid converts the insoluble phosphorous (P) compounds to simple plant available P compounds. Best strains were screened out on the basis of morphological and biochemical characteristics, pH reduction test, sulphate ion production test, indole acetic production test. Among 30 isolates 10 were capable of reducing the pH of the growth media below 4.0 from initial pH 8.0 and made the highest sulphate production in the growth media and concentration of produced sulfate ion ranged from 1.73 to 2.0063mg/mL. On the basis of pH reduction (in thiosulphate broth) and phosphorous solubilization index (PSI) best strains were screened out. A total of ten selected SOB were tested in 0.5% tricalcium phosphate (TCP) broth media for the efficiency Phosphorous solubilization. Results showed that the strain Endo2 released 2.0435 mg L-1 P (95.2%) during 45 days of incubation shows Capacity of Phosphorus dissolved had a significant correlation revise this line. The bacterial isolates were identified as Bacillus spp., Serratia spp. and Enterobacter spp thiobacillus spp. based on their 16Srna, morphological and biochemical characterization.