Biochemistry of soils derived from volcanic ashes. IV. Solubilization of phosphates by soil fungi

Fernando Borie B.1, Josué Quinteros Q.2 y María Aguilera S.3

The number of phosphate solubilizing bacteria and fungi in seven volcanic soils was investigated. The results led to conclude that the fungi population is more active, specially in solubilizing organic phosphates. The amounts of P released by the action of four active fungi strains (Penidihium sp., AspergiÍíus níger, Mucor sp. and a possible Botrytis sp.), from five inorganic and organic phosphates and two types of phosphate rocks, were evaluated. The results show that Aspergillus niger and Botrytis sp. are active in releasing phosphorus, particularly from aluminium phytate. The possible mechanims involved in the P-solubilization and their occurrence in volcanic ash derived soils are discussed.

1 Fac. Ciencias Químicas. U. de Chile. Actualmente: Depto. Ciencias Químicas, Fac. Ingeniería, U. La Frontera, Casilla 54-D, Temuco, Chile.
2 Químico. Profesor visitante, Fac. Ciencias Químicas. U. de Chile (1981), U. Nacional de Colombia.
3 Fac. Ciencias Químicas, U. de Chile, Casilla 233, Santiago, Chile.