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This study investigates the use of a barley-associated Erwinia gerundensis strain as a biocontrol agent for the protection of malt against fungal development and mycotoxin production during the malting of barley. First, the antifungal activity of E. gerundensis was studied via simultaneous co-cultures in Yeast Malt broth and on barley kernels artificially infected with Fusarium tricinctum. Then, the effect of E. gerundensis on the fungal load and mycotoxin content of malt obtained from naturally contaminated barley was studied by applying different doses of the bacterial strain at the steeping step of the malting process. Mycotoxin concentrations were determined using the technique of liquid chromatography coupled to the mass spectrometry detector in tandem (LC-MS/MS). Also, the effect of E. gerundensis on the technological quality of the final malt was evaluated using European Brewery Convention standard methods. The bacterial strain reduced the production of enniatin (ENN) by 97.7–99.8% and 38–68% in the liquid medium and on barley kernels, respectively, along with 0–82% Fusarium tricinctum growth reduction on barley kernels. Application of E. gerundensis at the beginning of the steeping step reduced the fungal load of the final malt by 67–72% and its ENN and deoxynivalenol (DON) contents by 32–50% and 15–33%, respectively, depending on the treatment dose. Barley malts treated with E. gerundensis showed no degradation in their technological quality, thus making E. gerundensis a potentially interesting biocontrol agent for the malting and brewing industries. Further investigation should be focused on improving the bioprotective capability of the proposed biocontrol agent. [ABSTRACT FROM AUTHOR]

Fusarium tricinctum is among the pathogenic fungi that contaminate cereal crops, including barley. It produces toxic metabolites such as enniatins (ENNs) that affect the quality and safety of barley-based products such as malt and beer, thus representing a significant concern for the cereal industries. Therefore, it is critical to reduce Fusarium spp. development and enniatin contamination in cereal-based products. Fungicides are commonly used during agricultural practices, but they are facing growing fungal resistance and environmental and health concerns. Hence, there is need to define environmentally friendly control strategies. This study highlights the ability of a bacterial strain isolated from barley kernels, namely Erwinia gerundensis 6E4, to inhibit the growth of Fusarium tricinctum and to reduce its toxigenic potential. First, E. gerundensis 6E4 exhibited a significant fungistatic activity against pathogenic fungal strains during co-cultures, with fungal growth reduced by up to 100% on Petri dishes and by about 69% in liquid medium. The bacterial strain also led to a drastic reduction (74 to 100%) of ENNs production by F. tricinctum strains over 72 h co-cultures. Based on these results, our study supports the use of E. gerundensis 6E4 as a biocontrol agent in strategies aiming at reducing the presence of Fusarium tricinctum and enniatins in cereal-based products, or as a food and feed supplement for the bio-detoxification of enniatins. [ABSTRACT FROM AUTHOR]