Cytological effects of fungal metabolites produced by fungi isolated from Egyptian poultry feedstuffs.

The cytogenetic effects of fungal metabolites produced by 113 strains belonging to 36 fungal species and isolated form 5 substrates of commercial poultry feedstuffs were tested for their effect on the growing root meristems of Allium cepa. The fungal metabolites of Paecilomyces canescens, Aspergillus fumigatus, Syncephalastrum racemosum, Aspergillus terreus and Mucor hiemalis strongly suppressed cell division. Metabolites from other strains had less effect on cell division but permitted the appearance of several abnormalities through different mitotic stages. In general, chromosomal aberrations were more obvious with metabolites of Aspergillus species, Mucor circinelloides and Cladosporium cladosporioides. The mutagenic effects produced by these fungal metabolites reflect the risk that might take place through the consumption of these contaminated feedstuffs.

Fungal flora of Egyptian baladi bread with special reference to the mutagenic effects of their toxic metabolites.

The fungal flora of wheat flour and baladi bread in upper Egypt were investigated. Most of the isolated fungal species belong to the genus Aspergillus. The presence of non heat resistant fungi of the both flat surfaces of baladi bread, came from contamination after baking and from improper handling at homes. Among the heat resistant fungi, A. fumigatus and A. niger, were recorded to inhabit the spongy crumb although the high temperature of baking process which reached approximately 100 degrees C in the center of the bread. The mutagenic effects of the fungal metabolites of the extract of mouldy Egypt were investigated. Most of the isolated fungal species all stages of mitotic division. The most interesting effect of these fungal metabolites were the induction of tripolar and quadripolar spindle. Multinucleate and polyploid cells were also observed under relatively high concentrations. It was noticed that at either higher concentrations or lower concentrations with long exposure, damaged cells were observed. The hazards involved through the consumption of individuals to such mouldy bread, is accumulation of possible deleterious effects from both long and short term exposure to these toxic metabolites.

Mutagenic effects of aflatoxin B-1 and G-1 on the Egyptian cotton leaf-worm, Spodoptera littoralis (Boisd.).

The aim of this study was to test infertility of the Egyptian cotton leaf-worm, Spodoptera littoralis. Three concentrations, 0.8, 1.6 and 2.0 micrograms/larva of aflatoxin B-1 and G-1 were applied to the final instar of the larval period. Both B-1 and G-1 induced mutagenic effects on spermatogenesis and morphogenesis which consequently reflected in infertility of Spodoptera littoralis. The phenomenon of mutagenicity was more obvious in larvae treated with G-1 rather than in those treated with B-1. The two analogues were also capable of inducing malformations in sperms. These abnormalities were transmitted to and inherited by the progeny.