Mycotoxin producibility of the fungi isolated from wheat and barley grains

Samples of wheat and barley grains in the domestic marketing channel from 1971 to 1972, were obtained and examined for their fungal contamination by means of the mycological method. Fungi which emerged from surface-sterilized grains, plated on Potato-Dextrose Agar containing chloramphenicol and on PDA containing 25% dextrose, were isolated and identified. Aspergillus, Penicillium, and Alternaria were predominantly found in 70-80% of the all samples and Cladosporium, Rhizopus and Mucor were commonly isolated, but Fusarium was not frequently detected. Eighteen point eight percent of the wheat samples and 39.3% of the barley samples were recognized as a highly contaminated sample carring the genus Aspergillus. Aspergillus flavus appeared in 44% of the wheat and 31% of the barley, and 8% of the wheat samples and 10% of the barley samples were found as a highly contaminated sample. A. versicolor occured in 38% of the barley samples and 16% of the wheat samples and its highly contaminated barley samples were accounted for about 7%. A. ochraceus and A. clavatus were isolated from 14 to 25% of the wheat and barley samples, but only 2% of these positive samples showed a high contamination with the both fungi. Representative strains of the genus Aspergillus isolated from all the sample grains were determined chemically for their mycotoxin producibility on either liquid or solid media. Mycotoxin-producing strains were: nine Aflatoxins-producing strains from 58 strains of A. flavus (15.5%); 32 Sterigmatocystin-producing strains from 48 strains of A. versicolor (66.7%); 5 Ochratoxin A-producing strains (23.6%) and 17 Penicillic acid-producing strains (77.3%) from 22 strains of A. ochraceus; 10 Patulin-producing strains from 13 strains of A. clavatus (77%).