Solubilization of CaHPO4 and AlPO4 by Aspergillus niger in culture media with different carbon and nitrogen sources

• Autor(a) principal: Barroso,Cinthya Babá
• Data de Publicação: 2006
• Outros Autores: Pereira,Gener Tadeu, Nahas,Ely
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Brazilian Journal of Microbiology
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822006000400006
• topic: nutrition; phosphorus; phosphate source; phosphate solubilization; titratable acidity

The solubilization of inorganic phosphates by microorganisms supplies phosphates for plant nutrition and increases their growth. The solubilization of CaHPO4 (Ca-P) and AlPO4 (Al-P) by Aspergillus niger using several carbon and nitrogen sources was studied. Solubilization of Ca-P was enhanced when the carbon sources were mannitol, maltose, galactose and glucose (in that order). Galactose, sucrose and maltose were the carbon sources that enhanced the solubilization of Al-P. More extensive growth, acid production, and decrease in pH were obtained in the Al-P medium than in the Ca-P medium, however, the quantity of solubilized phosphate was 12% less. Phosphate solubilization was related to acid production, pH drop and fungal growth in the culture medium. The results of a study carried out under abiotic conditions showed that organic acids solubilize more Ca-P than Al-P. Evaluating the effect of the nitrogen source, the solubilization of Ca-P or Al-P decreased in the following order: glycine > NH4Cl > NaNO3 and NH4NO3 > urea > (NH4)2SO4, respectively. Ammoniacal nitrogen (NH4+-N) sources were the most effective in the production of acids and in lowering of the pH.