| Congresso Brasileiro de Microbiologia 2023 | Resumo: 839-1 | ||||
Resumo:Maize (Zea mays L.) is an economically important crop used in different conditions as human and animal food. However, maize crops are constantly affected by several diseases, which cause productivity losses and frequently reduce kernel quality. The fungus Fusarium verticillioides affects all stages of plant development, inducing premature seedling death, rot symptoms, and kernel contamination by fumonisins. Managing this disease with fungicides is currently linked with increased fumonisins in grains. Thus, using beneficial microorganisms as biological control agents is a viable and complementary alternative to fungicides. This strategy protects maize plants against F. verticillioides colonization, reducing the infection and producing grains with better sanity. This study tested the effect of volatile organic compounds produced by Paenibacillus polymyxa (LIS03) and Bacillus velezensis (CNPMS22) to inhibit the growth of F. verticillioides (CML2778) in vitro. 20µL of each bacterial strain grown overnight in TSB was spread in Petri dishes containing PDA and incubated at 28 °C for 48h. Sterilized grains of maize were inoculated with a conidia suspension (106 conidia.mL-1) of F.verticillioides and adhered to a PDA plate's center. The plates containing the inoculated grains were inverted over the antagonist plates, sealed with parafilm, and incubated at 28 °C for 12 days. Control samples were prepared with a noninoculated plate instead of one containing the antagonist. The mycelial area was measured using ImageJ software, and the percentage reduction was calculated. In the control samples, the CML2778 mycelial area reached 40.2 cm2, while in plates exposed to VOCs, CML2778 showed a mycelial area of 11.18 and 7.69 cm2 for LIS03 and CNPMS22, respectively. These values represent a reduction of 72 and 80% in the CML2778 growth. Moreover, contact with VOCs promoted depigmentation of the CML2778 colony, which changed from purple to white. The results revealed the potentiality of VOCs as a biocontrol resource against F. verticillioides, an important mycotoxigenic fungal. Microbial producing VOCs are a sustainable and efficient alternative to synthetic fungicides for controlling postharvest pathogens, especially in stored food and feed. Palavras-chave: biological control, fumonisin, fusarium rot, maize Agência de fomento:CAPES. CNPq. Embrapa Milho e Sorgo. Finep. | |||||