Phosphorus Dissolution by Microbial Activities: 1.Dissolution of Rock Phosphate by Thiobacillus

Abstract

The objective of this study was to evaluate the role of microbial activities on phosphorus dissolution. The 'tudy was performed by inoculating fresh and sterilized cells of Thiobacillus into flasks containing Thiobacillus medium with various amounts of rock phosphate. The flasks were incubated under shaking conditions at 28' C for 8 weeks. available phosphorus was analized weekly throughout the period of experiment. The experimental results showed that upon inoculation with fresh cells the available phosphorus concentration was markedly increased with incubation time, except those of treatments with sterilized cells. The marked increase in available phosphorus concentration was also observed with increasing rock phosphates, but the percentages of dissolution tended to decrease. Very slightly increase in soluble phosphorus was also observed with medium treated with sterilized cells, and approximately constant percentages of dissolution being observed. The dissolution of phosphate frdm rock phosphate appeared to qe significantly affected by activities or microorganism and quantities of rock phosphate added. It is suggested that rock phosphate could be dissolved through Thiobacillus activities and further studies leading to effectively practical used of rock phosphate are being warranted.