Detoxification of the Mycotoxin Citrinin by a Manganese Peroxidase from Moniliophthora roreri .

Citrinin (CIT) is a mycotoxin found in foods and feeds and most commonly discovered in red yeast rice, a food additive made from ordinary rice by fermentation with . Currently, no enzyme is known to be able to degrade CIT effectively. In this study, it was discovered that manganese peroxidase (MnP) from could degrade CIT. The degradation appeared to be fulfilled by a combination of direct and indirect actions of the MnP with the CIT. Pure CIT, at a final concentration of 10 mg/L, was completely degraded by MnP within 72 h. One degradation product was identified to be dihydrocitrinone. The toxicity of the CIT-degradation product decreased, as monitored by the increased survival rate of the Caco-2 cells incubated with MnP-treated CIT. In addition, MnP could degrade CIT (with a starting concentration of up to 4.6 mg/L) completely contaminated in red yeast rice. MnP serves as an excellent candidate enzyme for CIT detoxification.