Atividade antimicrobiana de Bacillus subtilis em Fusarium sp., comparando três diferentes métodos (confronto indireto, confronto direto e metabólitos voláteis)

Abstract

The fungus Fusarium is responsible for causing diseases in corn, wheat, soybeans, potatoes, and even tomatoes, leading to wilt and root rot, also known as sudden death syndrome or fusariosis, which results in a significant reduction in the productivity of various crops. Due to the great difficulty in controlling the disease caused by the fungus and in the quest to replace chemical pesticides, alternatives have been sought to integrate the management of fusariosis. This study evaluated the antagonistic potential of Bacillus subtilis isolates in the biocontrol of Fusarium sp. In vitro assays were performed to evaluate antagonism through three different methods: indirect confrontation, direct confrontation, and volatile metabolites, using three inoculum concentrations, 10 μL, 20 μL, and 40 μL, in addition to the control plate. In the indirect confrontation method, bacterial inhibition was not effective. In the direct confrontation method, the results were effective at all tested concentrations, as in this method, the microorganisms are in direct contact. In the volatile metabolites method, only the 40 μL concentration was effective. The evaluation of the antimicrobial activity of Bacillus subtilis against Fusarium sp. was promising when using direct contact methods, acting as a potential biological control agent.