title: Factors determining rock phosphate solubilization by microorganisms isolated from soil.
abstract: Forty two soil isolates (31 bacteria and 11 fungi) were studied for their ability to solubilize rock phosphate and calcium phosphate in culture medium. Eight bacteria and 8 fungi possessed solubilizing ability. Pseudomonas cepacia and Penicillium purpurogenum showed the highest activity. There was a correlation between final pH value and titratable acidity (r=-0.29 to -0.87) and between titratable acidity and soluble phosphate (r=0.22 to 0.99). Correlation values were functions of insoluble phosphate and of the group of microorganisms considered. A high correlation was observed between final pH and soluble phosphate only for the rock phosphates inoculated with the highest concentration of solubilizing bacteria (r=-0.73 to -0.98).
authors.affiliation: Departamento de Microbiologia, Faculdade de Ciências Agrárias e Veterinárias, UNESP (Department of Microbiology, Faculty of Agrarian and Veterinary Sciences, UNESP), 14.870-000, Jaboticabal, SP, Brasil.
authors.forename: E
authors.initials: E
authors.lastname: Nahas