Researches about microbiological activity on many plants rizosphere led to the discovery of groups of important microrganisms for plants development. Among them there are the rizobacteria able to colonize the roots, stimulating directly or benefiting many plants. These bacteria are called Growth Promoting Rizobacteria or GPR. In view of this, the present study was performed, aiming to isolate, identify and test phosphate solubilization and acetic indol acid (AIA) production in bacteria that lives in maize roots. The partial analysis of the 16S rRNA gene of the 58 isolates enabled the identification of the genres Bacillus, Burkholderia and Azospirillum, and the most frequent totaling 86% of the isolates, followed by Sphingomonas, Pseudomonas, Herbaspirillum, Pantoea and Bosea. Out of the 58 isolates, 27 showed the capacity of phosphate solubilization and 18 were positive to the AIA production colorimetric detection test. From these results was chosen an organism belonging to the genre Sphingomonas to be tested at greenhouse as growth promoter with the strains Azospirillum brasiliense (AbV5 e AbV6). The plants were assessed twenty and seventy days after germination. Dry mass of shoot and root parts were quantified after seventy days at the end of the experiment. Statistical analysis indicated by the program Statistix v.9.0 showed that the isolates belonging to the genre Sphingomonas presented similar results as shown by strains AbV5 and AbV6 on maize plant. This microorganism may become a promising one to be used as a GPR
GPR; indol acetic acid; phosphate solublization; Sphingomonas spp
