Solubilization of Al- and Fe-phosphates by bacteria isolated from the rhizosphere of Theobroma grandiflorum (Willd. ex Spreng.) Schum.

One hyndred sixty-eight bacterial isolates from the rhizoplane and rhizosphere (2mm-10mm away from the root surface) of cupuacu were isolated in spring 1997 in an experimental polyculture site (SHIFT ENV-23) near Manaus and their capacity to grow on media with poorly soluble AlPO4 was determined. 75% of the isolated bacteria were found to be effective in solubilizing hardly-soluble AlPO4 and FePO4. Two strains were selected because of their ability to solubilize high amounts (>50ug P/ml) of AlPO4 and FePO4 in former experiments. Their capacity to solubilize inorganic phosphates was investigated in liquid culture. Both strains solubilized similar amounts of P. The amount of P solubilization was highest after three days of growth while cell numbers were maximal after 13 days. During the solubilization process one strain show a decrease in pH while the other strain increased the pH. This incates that the solubilization of inorganic phosphates is not necessarily related to the acidification.

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Bibliographic Details
Main Authors: MARINO, W. T., SILVA JUNIOR, J. P. da, MARSCHNER, P., LIEBEREI, R.
Other Authors: University of Hamburg
Format: Parte de livro biblioteca
Language:English
eng
Published: 1999-09-29
Subjects:Agrofloresta, Brasil, Amazonas, Manaus., Bactéria, Cupuaçu, Cultivo Multiplo, Rizosfera, Theobroma Grandiflorum., agroforestry, multiple cropping.,
Online Access:http://www.alice.cnptia.embrapa.br/alice/handle/doc/668385
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Summary:One hyndred sixty-eight bacterial isolates from the rhizoplane and rhizosphere (2mm-10mm away from the root surface) of cupuacu were isolated in spring 1997 in an experimental polyculture site (SHIFT ENV-23) near Manaus and their capacity to grow on media with poorly soluble AlPO4 was determined. 75% of the isolated bacteria were found to be effective in solubilizing hardly-soluble AlPO4 and FePO4. Two strains were selected because of their ability to solubilize high amounts (>50ug P/ml) of AlPO4 and FePO4 in former experiments. Their capacity to solubilize inorganic phosphates was investigated in liquid culture. Both strains solubilized similar amounts of P. The amount of P solubilization was highest after three days of growth while cell numbers were maximal after 13 days. During the solubilization process one strain show a decrease in pH while the other strain increased the pH. This incates that the solubilization of inorganic phosphates is not necessarily related to the acidification.