A mycotoxicological survey on soil-borne Aspergilli in 268 soil samples collected from 11 areas in Shantung, China, was carried out. Aspergilli were isolated by using the soil-plate method on Czapek's agar, incubating the plates at 37°C for 10 days. The most common Aspergilli were Aspergillus flavus, A. fumigatus, A. niger, A. terreus and Emericella nidulans. Petromyces alliaceus was also frequently isolated. A higher occurrence of A. flavus was generally shown in the soil samples of road side and cultivated fields; while Emericella spp. highly occurred in those from paddy field, road side and cultivated fields. The Emericella isolates were identified with E. acristata and E. nidulans. For the 45 isolates of A. flavus and A. parasiticus, their ability to produce afiatoxins (AF) was examined on YES medium at 25°C for 7 days. The following AFB
1 producers were found by TLC : A. flavus (12 positive strains/44 tested strains) and A. parasiticus (1/1). The levels of AFB
1 production ranged between trace and 32μg per ml. For the 44 isolates of E. acristata and E. nidulans, their ability to produce sterigmatocystin (STG) was examined on rice at 25°C for 21 days. The following STG producers were found by HPLC: E. nidulans (26/43). The levels of STG production ranged between 0.26 and 5.63 μg per g of the rice.
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