Pathogenic fungi represent a generic problem for cereals as they can produce a variety of toxic secondary metabolites such as mycotoxins that represent a significant concern for the malting and brewing industries, and may affect the quality and safety of barley, malt, and beer. Besides, this situation is worsening due to the highly variable climatic conditions that favor pathogenic fungi development and the societal desire to reduce the use of phytosanitary products, including fungicides. In this context, this communication describes the development of an innovative bio-control process applicable in malting facilities, that would contribute to guaranteeing a better hygienic and technological quality of malt, despite the increasingly complex and variable conditions for barley production. The process is based on technological bacteria, isolated from infection-resistant barley cultures, that can reduce the development of spoilage fungi and the associated mycotoxin production. The experimental approach consists of: i) determining the growth kinetics of the bacterial and fungal strains by co-culturing in order to evaluate the impact of the bacteria on the fungal pathogens; ii) carrying out a micro-malting process in order to develop the aforementioned process, and iii) evaluating the technological and sanitary properties of the generated barley malts in order to validate the process developed. The findings highlight the ability of a barley-associated novel bacterial strain, Erwinia gerundensis, to inhibit the growth of fungal species and to reduce their toxigenic potential. E. gerundensis exhibited a significant fungistatic activity against pathogenic fungi by reducing their growth by up to 80%, and their mycotoxin production by 70 to 100% in liquid medium and on barley matrix. In addition, micro-malting assays carried out using naturally contaminated barley kernels have revealed that the bacterial strain was capable of reducing the fungal load and mycotoxin (enniatin) content of malt by 70% and 50% respectively, without any degradation of its technological quality. Based on these results, our study supports the use of Erwinia gerundensis as a biocontrol agent in strategies aiming at reducing the presence of pathogenic fungi and mycotoxins in cereal-based products, or as a food and feed supplement for the bio-detoxification of mycotoxins. The biocontrol process based on this bacterial strain is therefore expected to make it possible to guarantee an irreproachable hygienic and technological quality of the malt obtained from barley, thus significantly reducing the setbacks related to pathogenic fungi and mycotoxins in the brewing industry. The use of this process would also contribute to the reduction of contamination levels of malting plant effluents. Finally, future works are required to effectively evaluate the impact of Erwinia gerundensis during brewing and on beer quality. [This paper was presented at "The 38 EBC Congress" held at Madrid, Spain].
