Impact of Erwinia gerundensis as a Biocontrol Agent on the Sanitary and Technological Quality of Barley Malt

Abstract

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.

Keywords:

• Pathogenic fungi
• mycotoxins
• Erwinia gerundensis
• biocontrol agent
• malting

Acknowledgment

The authors would like to thank Noémie Wiatrak, Elodie Hoch, Annelore Elfassy, Cécile Mangavel, Marcia Leyva-Salas, Sophie Slezack, Séverine Piutti, and Julie Genestier for their valuable support.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This research work was supported by the French Ministry of Agriculture and Food, within the framework of the Joint Technological Unit OPTIMALT (Nancy, France), and funded by the Fondation de la Brasserie et de la Malterie Françaises (France), the Région Grand-Est (France), and the University of Lorraine (France) as part of a PhD fellowship.