Bio Prospecting Plant Growth-Promoting Bacteria Isolated from Maize (zea mays l.) Roots

Abstract

Maize (Zea mays L.) culture has a great importance in several countries, especially in Brazil the third-largest world producer. The increase in maize production has been achieved with a high use of fungicide; however, in view of a more sustainable agriculture plant growth promoting bacteria have been explored aiming for the replacement of chemical fertilizers and biological control. In this study, we investigated the bacterial community isolated from maize roots in order to evaluate their capacity of growth promotion as well as of inhibition of fungal species associated with maize leaf diseases. All isolates evaluated were positive for at least one of the parameters evaluated-growth promotion, enzymatic production or bio control. The best results were observed for Enterobacter sp. LGMB221 and Bacillus sp. LGMB242 that showed the high potential for growth promotion, acting in the early stage of maize seedlings development. Bacillus sp. LGMB152 showed the best enzymatic results, indicating that it might play a role against pathogens, a premise supported by the antagonist activity observed. The next steps involve evaluations under field conditions to confirm if these isolates have biotechnological potential as inoculants for the maize crop. In addition, we suggest that Enterobacter strains LGMB221 and LGMB235 and Escherichia strain LGMB159 might represent new species, indicating the high diversity of bacteria in maize rhizosphere that remains to be determined.