Effects of mycotoxins, aflatoxin B1 and deoxynivalenol, on the bioluminescence of Vibrio fischeri

The effects of aflatoxin B-1 and deoxynivalenol on the luminescence of Vibrio fischeri were investigated to determine the conditions of using the bioluminescence as an indirect means for mycotoxin detection. The culture of Vibrio fischeri showed that bioluminescence reached a peak after 12 hours of incubation at 25 degrees C and then decreased drastically. During the lag phase which lasted 6 hours, light emission decreased drastically for both the mycotoxin assays aflatoxin B-1 10 mu g/ml and deoxynivalenol 20 mu g/ml - and the corresponding controls. Distinct bioluminescence inhibition appeared after this period of minimal bioluminescence of the controls and started with the exponential phase of growth. The percentage of bioluminescence inhibition for both mycotoxins was determined after 3.5, 10, 15 and 25 hours of incubation. The bioluminescence of Vibrio fischeri was inhibited with aflatoxin B-1 and enhanced with deoxynivalenol. Both effects were delayed and required a long-term incubation over 10 hours, which may help to investigate bioassays for mycotoxin detection.