ECOLOGICAL AND ENZYMATIC STUDIES ON FUNGI ASSOCIATED WITH BISCUITS INEGYPT

Some 43 species and four varieties belonging to nineteen genera were c ollected from 30 samples of six types of biscuit on 30% sucrose and 1% starch Czapek-Dox agars at 28-degrees-C. The most contaminated sample s were chocolate wafers with 327 and 195 colonies g-1, 12 and 8 genara and 18 and 13 species on the media, respectively. Samples of wafers w ithout jam and jam wafers were less contaminated with fungi. The most frequently isolated fungi on the two media were Alternaria alternata, Aspergillus alutaceus, A. fumigatus, A. niger, A. sydowii, Cladosporiu m cladosporioides, C. herbarum, Penicillium chrysogenum, P. janczewski i and yeasts (Saccharomyces spp.). The osmophiles, Eurotium amstelodam i and E. repens, were infrequently isolated from chocolates and jam-wa fer biscuits. All 69 isolates tested produced invertase and could prod uce 90%, respectively, amylase, caseinase, and catalase.