Design and characterization of an artificial two-strain bacterial consortium for the efficient biodegradation of deoxynivalenol

Deoxynivalenol (DON) is a trichothecene mycotoxin mainly produced by various Fusarium species which cause Fusarium head blight in cereals. DON accumulation in grains not only poses a serious health threat to human and animals but also causes economic loss in the food and livestock industries. Here we reported the construction of an artificial bacterial consortium comprising of Devosia sp. A8 and Paracoccus yeei A9 isolated from an enriched bacterial culture, which shows effective degradation capability towards DON. The optimal conditions for temperature, pH and initial inoculum volume for DON degradation were 35 degrees C, pH 8-9 and 0.5 %, respectively. The degradation product was identified as 3-keto-DON by LC-MS/MS and 1H NMR spectra. Devosia sp. A8 played the major role in DON degradation, but the enhancement of the DON degradation activity by adding NADPH or riboflavin suggested that Paracoccus yeei A9 provided electrons for Devosia sp. A8 to degrade DON. Moreover, other trichothecenes including 15-acetyl DON, 3-acetyl DON and T-2 toxin were also degraded by the consortium. To the best of our knowledge, this is the first report about a Devosia species capable of degrading DON when co-cultured with Paracoccus yeei. The results demonstrated that the artificial bacterial consortium is a potential candidate for DON biodegradation as well as other trichothecene mycotoxins in a safe and eco-friendly manner.