Anaerobic Digestion of Mycotoxin-Contaminated Wheat: Effects on Methane Yield and Contamination Level

Abstract

In this study, biogas and biomethane production during mesophilic anaerobic digestion of wheat substrates coming from national crops and naturally contaminated with deoxynivalenol (DON) and/or T-2/HT-2 toxins was investigated. Biochemical methane potential (BMP) tests of both wholewheat flour and of the main milling fractions were carried out to assess the effect on the concentration of mycotoxins on the anaerobic biological process and their residual presence in the final digestate. The good methane average production achieved (337.0 ± 24.5 NL CH4/kg VS) was substantially comparable with the yields gained from similar biomasses at mesophilic conditions. Moreover, an effective reduction (60.7–100%) of DON concentration was obtained in all the tested substrates (range of contamination in the samples, 368–12,916 μg/kg) whereas the sum of T-2 and HT-2 toxin levels in digestates was always <LOQ in all substrates analyzed (range of contamination in the samples, 5–65 μg/kg). The results supported an alternative exploitation of “non-compliant” lots of cereals destined for human consumption and/or animal feed which could represent a concrete benefit for agricultural producers. Anaerobic digestion could be employed as an effective tool to recover large amounts of trichothecene-contaminated cereals in an environmentally and economically sustainable way.