Deoxynivalenol Detoxification by a Novel Strain of Pichia kudriavzevii via Enzymatic Degradation and Cell Wall Adsorption

Deoxynivalenol (DON) is a mycotoxin that significantly threatens the food and feed industry. Corn steep liquor (CSL) is an acidic byproduct of the corn starch industry, and DON is concentrated in CSL once the material is contaminated. In this work, a Pichia kudriavzevii strain that could remove DON from CSL was isolated and characterized. The strain P. kudriavzevii E4-205 showed detoxifying activity in a pH range of 4.0 similar to 7.0 and temperature of 25 similar to 42 degrees C, and 39.4% DON was reduced by incubating this strain in CSL supernatant diluted by 2-fold (5 mu g/mL DON) for 48 h at pH 5.0 and 30 degrees C. Further mechanism studies showed that P. kudriavzevii E4-205 could adsorb DON by the cell wall and degrade DON by intracellular enzymes with NADH as a cofactor. The degradation product was identified as 3,7,8,15-tetrahydroxyscirpene by liquid chromatography-tandem mass spectrometry. DON adsorption by inactivated cells was characterized, and the adsorption followed pseudo first-order kinetics. This study revealed a novel mechanism by which microbes degrade DON and might serve as a guide for the development of DON biological detoxification methods.

Automated summary

In this study, a Pichia kudriavzevii strain capable of removing DON from CSL was isolated and characterized. The strain demonstrated detoxifying activity in a wide range of pH and temperature conditions, and the mechanism of DON degradation was elucidated. This research provides valuable insights for the development of biological detoxification methods for DON.