Food grade fungi were screened for their capacity to degrade aflatoxin B1(AFB1) in order to develop a biological detoxification process for contaminated feeds. An agar technique based on defluorescence of AFB1was used for this purpose. Good correlations were observed between defluorescent capacity, AFB1elimination and reduction of mutagenicity. Although not identified in these food grade fungi as yet, enzymatic studies performed separately withAspergillus flavusindicated the possible involvement of monooxygenase enzyme systems in AFB1degradation.