GAYOSSO-BARRAGÁN Odilon1*, RODRÍGUEZ-HERRERA Sergio Alfredo1, LÓPEZ-BENÍTEZ Alfonso1 y LUEVANOS-ESCAREÑO Miriam Paulina2.
1 Universidad Autónoma Agraria Antonio Narro, Buenavista, Saltillo, Coahuila, México
2 Facultad de Ciencias biológicas, Universidad Autónoma de Coahuila, Torreón Coahuila, México
The objective of this study was to isolate and identify phosphate solubilizing bacteria from the rhizosphere of Solanum rostratum Dunal plants and to evaluate their potential to dissolve tricalcium phosphate in Pikovskaya medium. Samples of rhizospheric soil were sampled for serial dilutions up to 10-5, samples were seeded in Petri dishes with Pikovskaya culture medium (PVK), the phosphate solubilizing efficiency index (ISF) and pH change were evaluated for seven days. Twenty bacterial strains were isolated and purified by serial dilutions, of which only five retained their solubilizing capacity at the time of re-inoculation. Solubilization rates were recorded with values of 2.25, 2.22 and 2.17 with significant differences. The five bacterial strains studied decreased the pH of the PVK medium compared to the uninoculated sterile control incubated for seven days. The pH gradually decreased during the first days of incubation to values in the range of 4.35 and 3.10. The strains evaluated at the laboratory level showed potential to dissolve tricalcium phosphate and it is suggested to carry out subsequent evaluations at the field level.