Survey of mycoflora and mycotoxins in Egyptian soybean seeds

After four months in commercial storage, 100 soybean samples from different places of Egyptian Governorates were assayed for filamentous fungal growth at two incubation temperatures (28 and 45 degrees C). 73 species and 8 varieties belonging to 32 genera were isolated by the dilution plate method. At 28 degrees C, the common species were Aspergillus flavus, A. fumigatus, A. niger and A. alutaceus, followed by A. terreus, Penicillium chrysogenum, P. citrinum, Mucor hiemalis, M. racemosus, Emericella nidulans, Rhizopus stolonifer, Nectria haematococca and Scopulariopsis brevicaulis. At 45 degrees C, A. fumigatus was the dominant species followed by Rhizomucor pusillus, Emericella nidulans and Neosartorya fischeri. Penicillium which was one of the most abundant genus at 28 degrees C, absent at 45 degrees C. The seeds were assayed for aflatoxin, ochratoxin A, sterigmatocystin, T-2 and zearalenone by thin layer chromatographic analysis. Aflatoxin was detected in 35% of soybean seed samples (5-35 micrograms/kg). The other mycotoxins were not detected.