Isolamento e caracterização morfocultural de rizobactérias promotoras de crescimento em plantas obtidas em solos agrícolas no município de São João do Piauí

Abstract

In the rhizosphere, various types of bacteria are present. The interaction of these bacteria with plants provides benefits such as nitrogen fixation, which benefits not only the plants but also the soil. Thus, bacteria constitute the largest microbial component of the soil, whether in number or diversity, and various distinct species can be found. The aim was to isolate rhizobacteria collected from the teaching garden of the Federal Institute of Piauí (IFPI) for morphocultural characterization in the city of São João do Piauí. The bacteria were collected from three different locations of banana-prata-anã, sugarcane, cowpea, and BRS capiaçu in the teaching garden of IFPI, São João do Piauí campus. Isolation was carried out from the rhizosphere of the banana Prata Anã, sugarcane, BRS Capiaçu, and cowpea areas in the IFPI Biology Laboratory, after washing with running water and isolating them in NYDA culture medium. They were incubated at approximately 28°C for 48 hours. After this period, they were subcultured, morphologically characterized, and subjected to the Gram test to identify them as positive or negative. A total of 24 bacteria were isolated, with 20.8% from banana Prata Anã, 20.8% from sugarcane, 25% from BRS Capiaçu, and 33.4% from cowpea. The obtained rhizobacteria displayed distinct colors and characteristics, and they underwent the morphocultural characterization process, resulting in the formation of a dendrogram to assess the degree of similarity among these bacteria, as well as the different types and groups, showing a diversity of cultural morphology with eight different groups, including Gram-positive bacteria.