Comparison of in vitro solubilization activity of diverse of phosphate-solubilizing bacteria native to acid soil and their ability to promote Phaseolus vulgaris growth

COLLAVINO M.M, P. A. SANSBERRO, L. A. MROGINSKI, AND O. M. AGUILAR

BIOLOGY AND FERTILITY OF SOILS

SPRINGER

Año: 2010 vol. 46 p. 727 - 738

0178-2762

In order to identify plant growth promotion ability of phosphorus-solubilizing native bacteria we have examined a collection of isolates representing the diversity of culturable phosphate-solubilizing bacteria (PSB) from acid soils of the Northeast of Argentina, where yerba mate (Ilex paraguariensis St. Hil.) is intensively cultivated. Assays in growth medium supplemented with tricalcium phosphate revealed different degrees of phosphorus solubilization activity and different temporal patterns of solubilization. Acidification of the broth medium coincided with the phosphorus solubilisation. The isolates were grouped according to their Rep-fingerprinting profiles and phylogenetically classified by 16S rDNA and biochemical analyses. These isolates were assigned to the genera Enterobacter, Pantoea, Pseudomonas, Acinetobacter, Burkholderia and Exiguobacterium. Four isolates showing high phosphorus solubilizing activity in in vitro assays were inoculated on common beans (Phaseolus vulgaris); some of them promoted plant growth and increased photosynthesis and the P and N content in leaves.