There were significant differences between controls and inoculated plants. Positive effects across maize cultivars were observed with 10 isolates from 22, whose inoculation resulted in an increase on shoot biomass over uninoculated controls without N. H. frisingense, EMA117 was the only strain that showed positive effect on both maize cultivars. It was observed a significant interaction between inoculation treatment 脳 maize cultivars in shoot and root dry weight (P < 0.05). Only one strain, Pseudomona flourescen, increased significantly the growth of the radicle compared to that of the controls without inoculation. In conclusion, maize inoculation experiments showed significant increases in shoot dry weight under controlled conditions but it is not clearly related to IAA production, P solubilization capacity or to more N efficiency assimilation. There is a potential PGPB in maize cultivars, but the results indicate the need for a better understanding of plant-bacteria interactions and to investigate plant colonization by endophytic bacteria.