Biocontrol potential of bacteria and fungi isolated from Zea mays L. (Maize) grains against fumonisins produced by Fusarium verticillioides

Abstract

The phytopathogenic fungus Fusarium verticillioides produces fumonisins, mycotoxins that contaminate grains of Zea mays L. (maize) and pose a risk to human and animal health. The aim of this study was to evaluate the efficiency of bacteria and filamentous fungi in controlling toxigenic F. verticillioides in maize. Microorganisms associated with maize grains were isolated and identified, and their ability to inhibit pathogen growth and reduce total fumonisin production was assessed. The microorganism showing the highest efficiency was subsequently identified by molecular methods. Fungi belonging to the genera Fusarium (85.71%), Aspergillus (57.14%), Penicillium (21.43%), and Trichoderma (9.52%) were recovered in maize grain samples, based on the total analyzed. 71.1% of the F. verticillioides isolates were toxigenic, producing fumonisin concentrations ranging from 30 to 4,010 ppb, with strain H08 showing particularly high levels. In antagonism assays, 90.7% of the bacterial isolates and 42.7% of the filamentous fungi exhibited inhibitory activity against the pathogen. Trichoderma atroviride strain 3 showed the highest efficiency, reducing mycelial growth by 84.94% and fumonisin concentration by 99.77%, demonstrating strong potential to reduce maize contamination by toxigenic F. verticillioides.