Yeast and bacteria from ensiled high moisture maize grains as potential mitigation agents of fumonisin B.

Background: Fumonisin B (FB ) is a mycotoxin produced by several Fusarium species and is a very common contaminant of maize-based food and feed throughout the world. The selection and use of FB -degrading microorganisms appears as a promising alternative to cope with the problem of toxicity towards humans and livestock. High moisture maize grain silage, which is based on natural maize fermentation, could be an interesting reservoir of such microorganisms.

Results: Using an in vitro simulated silage model with FB naturally contaminated grains, we demonstrated a significant raw decrease in FB during ensiling process ascribed to biodegradation mechanisms. A panel of 98 bacteria and yeasts were isolated from this matrix and selected for their ability to use FB as the sole source of C and N. For nine of them, the ability to degrade FB in vitro was evidenced. Notably, two bacteria identified as Lactobacillus sp. were highlighted for their efficient FB -degrading capacity and production of hydrolysed FB as intermediate degradation metabolite.

Conclusion: Fermentation of high moisture maize grain contaminated with FB leads to a significant reduction of the toxin and allows the isolation of FB -degrading microorganisms that could further be used as FB decontaminating agents. © 2016 Society of Chemical Industry.