Microbe-Mediated Removal of Zearalenone Using Yeast Strain <i>Rhodotorula dairenensis</i> Isolated from the Gut Microbiome of Zearalenone-Treated Mice

Mycotoxins contribute considerably to food losses and pose serious health risks to humans and animals. This study investigated the mechanisms underlying the elimination of mycotoxin zearalenone (ZEN) by a yeast strain, <i>Rhodotorula dairenensis</i> ZDY342B, which was isolated from the feces of ZEN-treated mice. Isotope-labeled ¹³C₁₈-ZEN was employed for accurately tracking the degradation products of ZEN, and the chemical composition of the yeast cells was characterized before and after ZEN elimination. The results of these analyses confirmed that strain ZDY342B removes ZEN via a combination of degradation and adsorption. Subsequently, the degradation product of ZEN was identified as zearalenol using high-performance liquid chromatography and nuclear magnetic resonance spectroscopy, as opposed to simply inferring the product structure based on the molecular weight of the degradation product. The characterization of the cell structure revealed the role of functional groups such as O-H, N-H, C═O, and C-O in the biosorption of ZEN by yeast ZDY342B. Additionally, an evaluation of the safety of strain ZDY342B revealed it to be a safe and harmless microorganism. Furthermore, the reduced toxicity of the products obtained upon the degradation of ZEN by ZDY342B was ascertained using in vitro and in vivo experiments. In summary, this study demonstrates the effectiveness and safety of ZDY342B, a yeast strain that shows the potential for mitigating ZEN contamination in food and animal feed.