Seleção de microrganismos promotores de crescimento vegetal isolados da rizosfera do tamboril (Enterolobium contorsiliquum)

Abstract

The Caatinga is a Brazilian biome that has a semi-arid climate, occupying around 11% of the Brazilian territory and 70% of the Northeast region. It has a great biodiversity of fauna, flora and microorganisms, many of its species are adapted to water stress and high temperatures. Enterolobium contortisiliquum, popularly known as monkfish, is a tree belonging to the legume family and which has adapted to the Brazilian Northeast, where it is easily found. The monkfish has rapid growth and large size, characteristics that demonstrate both its efficient microbial activity and its wide use in the reforestation of degraded areas. Therefore, the objective of the work is to isolate microorganisms from the rhizosphere of monkfish collected in the Paraíba caatinga and, therefore, select those that are promising for promoting plant growth. For this study, rhizospheric soil samples were collected in the city of Bananeiras-PB. Bacteria and fungi were isolated on potato dextrose agar and nutrient agar, respectively. Then, with the isolated colonies, the production of indole-3-acetic acid and the fixation of atmospheric nitrogen were evaluated. Atmospheric nitrogen fixation tests obtained positive results, with some caveats; tests for the production of indole-3-acetic acid proved to be very promising, with some microorganisms showing high levels of production of this auxin. Therefore, in accordance with what was developed in this work, in view of the complexity of these analyzes for determining plant growth-promoting microorganisms, it is important to highlight that research such as these should continue to be encouraged so that there is more knowledge about this theme.