Natural occurrence of mycotoxins and mycotoxigenic fungi on Libyan corn with special reference to mycotoxin control.
Eleven corn samples (9.2%) out of 120 tested proved to be toxic. Aflatoxins B1 and B2 were detected in (2 samples, 9.1-13.9 µg kg-1 corn), aflatoxins B1, B2, G1 and G2 (4 samples, 7.6-16.4), T-2 toxin (3 samples, 8.4-10.2), diacetoxyscirpenol (5 samples, 6.2-9.5) and zearalenone, (5 samples, 6.8-7.9). A. flavus, A. parasiticus and A. flavo-furcatis were the most prevalent Aspergillus species on 6 aflatoxins-contaminated corn samples. Aflatoxins B1 and B2 were produced by (12/18 isolates of A. parasiticus, 88.2-126.8 µg g-1 com), while aflatoxins B1, B2, G1 and G2 (13/29 isolates of A. flavus, 48.2-146.4) in addition to (2/18 isolates of A. flavo-furcatis, 28.6 and 36.2). This is the first report on aflatoxin production by A. flavo-furcatis. F. tricinctum, F. oysporum and F. equiseti were the dominant Fusarium species on 5 corn samples contaminated by microcyclic tricothecenes. T-2 toxin (15/20 isolates, 24.4-130.2 µg g-1 corn), diacetoxyscirpenol (18/20 isolates, 46.8-122.6) and zearalenone (17/20 isolates, 44.6-124.2) were produced by the previous Fusarium species (10, 5 and 5 isolates), respectively. Roridin E (8.2-38.6 µg g-1 corn) was produced as a macrocyclic trichothecene by four toxic isolates of Myrothecium roridum and unidentified toxic factor was produced by four toxic isolates of Acremonium strictum. Also, the effect of sodium chloride on mycotoxins synthesis was studied. This is the first report on mycotoxins and mycoflora contamination of Libyan corn.