MINERAL PHOSPHATE SOLUBILIZATION BY Burkholderia tropica

VERÓNICA GUIDI; GARCIA FERREYRA G.; MOYANO DAMIAN; CRESPO JUAN MANUEL; BOIARDI JOSE LUIS; LUNA MARIA FLAVIA

PUERTO MADRYN

Congreso; 46 Annual Meeting Argentine Society for Biochemistry and Molecular Biology; 2010

SAIB

116 Posters BIOCELL 34 (Suppl.), 2010 MI-P64 MINERAL PHOSPHATE SOLUBILIZATION BY Burkholderia tropica Guidi V, García Ferreyra G, Moyano D, Crespo JM, Boiardi JL, Luna MF CINDEFI (UNLP; CCT-La Plata, CONICET), Fac. Cs. Exactas, 47 y 115 (1900) La Plata, Argentina Conversion of soil insoluble phosphates to a form available for plants is a necessary goal to achieve for sustainable agricultural production. Burkholderia tropica strains have been reported to posses the ability to solubilize insoluble phosphates. Mineral phosphate solubilization (MPS) activity is usually related with the expression of a periplasmic glucose dehydrogenase (GDH), responsible for the conversion of glucose into gluconate. In the present work it was checked the ability of B. tropica to express an active GDH under different culture conditions and their relation with MPS activity. Plate assays using tricalcium phosphate (TCP) and different carbon sources, showed that B. tropica was able to solubilize inorganic phosphates with aldoses as carbon source but no solubilization was observed when other sugars were used. Batch cultures carried out with glucose as C-source showed GDH activity and gluconic acid production only in cultures using TCP. Soluble phosphorous concentration in the media increased together with the gluconic acid. These results indicate that phosphate solubilization was due to acidification via GDH activity and it seems that this activity is regulated by phosphate starvation.