Biocontrol of Fusarium graminearum and deoxynivalenol accumulation during the micromalting process

Abstract

Barley (Hordeum vulgare L.) is the second most important winter crop after wheat in Argentina, and is mainly used for the malt production in beer manufacture. Fusarium species, mainly Fusarium graminearum sensu stricto, cause Fusarium Head Blight in barley and produce quality and safety reduction during the malting process due to fungal growth and mycotoxin contamination. The aim of the present study was to evaluate the biocontrol ability of B. velezensis RC218 to reduce F. graminearum ss and DON accumulation during micromalting. The results showed that after the steeped stage there was an increase in the F. graminearum ss DNA content in both control treatments, positive and negative. Among the other stages a decrease of the F. graminearum levels was observed, which could be related to the changes in the ecosystem that occur during the micromalting process. The application of the biocontrol agent during the steeped stage showed reduction in the F. graminearum ss levels and the end of this stage. However, a higher effectiveness of the biocontrol agent was observed at the end of the micromalting process, when B. velezensis was applied during the germination stage. Deoxynivalenol accumulation was reduced in both conditions, in the stepping and germination stage. At the end of the process it was observed that the quality parameters were not affected.