MINERAL PHOSPHATE SOLUBILIZATION BY Burkholderia tropica

GUIDI V.; GARCIA FERREYRA G.; MOYANO D.; CRESPO JM; BOIARDI JL; LUNA, FLAVIA

Puerto Madryn

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

SOC. ARGENTINA DE INVESTIGACION BIOQUIMICA

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 result indicate that phosphate solubilization was due to acidification via GDH activity and it seems that this activity is regulated by phosphate starvation.