Abstract: Deoxynivalenol(DON) is a mycotoxin commonly contaminating cereal grains and grain products,which seriously threaten the safety and economic value of cereal food.Detoxification treatment of mycotoxins in cereal grains and feedstock by microbial degradation is an alternative approach with great potential.In this study,a microbial strain with DON degradation capacity was screened using the medium containing crude DON as sole carbon source extracted from corn inoculated with Fusarium graminearum.The sequence alignment of 16S r DNA of the microbial strain demonstrated that it is Pseudomonas aeruginosa.This strain could degrade 64.6%DON after incubation at 35℃for 72 h.The DON-degrading activity of Pseudomonas aeruginosa was predominantly attributed to the cell-free supernatant and this activity was found to be heat stable but sensitive to proteinase K treatment,indicating that the extracellular proteins or enzymes were responsible for the DON degradation.The DON was extracted from corn inoculated with F.graminearum with ultrasonic assisted extraction and DON degradation by Pseudomonas aeruginosa was tested,and it was found that the DON in corn reduced above 99.0% after extracted three times and 50.0%DON in corn extract was degraded by Pseudomonas aeruginosa after incubation at 35℃for 72 h.This study provides an experimental basis for the detoxification treatment of DON contaminated cereal grain and feedstock by Pseudomonas aeruginosa.