SUMMARY

The study aimed to know the possibility of using some of plants namely Barley, Wheat, Maize, Peanut and Sunflower as well as Saccharomyces cerevisia , physical condition such as temperature, pH and aeration on the ability of A. flavus and A. parasiticus in terms of growth and aflatoxin production .

The results revealed the contamination of plants sample with A. flavus and A. parasiticus in different number , percentage and frequencies . Maize samples gave higher percentage and contamination i.e. 48 isolates followed by wheat, bean, barly and sunflower giving 34, 32, 27 and 17 isolates respectively . peanut samples gave lower value 15 isolates .

The test by ammonia solution method show 18 isolations out of 30 from A. flavus had ability to produce of aflatoxins B₁ 60% , while A. parasiticus gave 55% .

extracts of Roselle , Eucalyptus and Mint plants either alcoholic or water at 10, 20 and 30 mg /ml inhibited the growth of those two fungi where alcoholic extracts of Roselle and Eucalyptus plants inhibited the growth by 100% at 30mg/ml, the colony appeared while white small isolate . the alcoholic extract was superior as compared with the water extract . results also revealed that , the treatment of those fungi with 20 and 30 mg/ml of alcohol extract of Roselle plant , water extract of Roselle , Eucalyptus and Mint plants as well as the treatment of fungi with 10% of water extract of Eucalyptus plant no aflatoxins B₁ was detected .

test indicated that the effective plants extracts contained many active compounds(ingredients) , alcoholic extract of Roselle plant contained all compounds except Saponins and Resins , whereas water extract of Roselle did not contain Saponins , Resins and Tannins . alcoholic extract of Eucalyptus contained all compounds except did not contain Triterpenoids ,whereas, its water extract did not contain Alkaloids , Saponins , Resins , Flavonoids and Triterpenoids . the alcoholic extract of Mint contained Alkaloids, Tannins, Saponins, Carbohydrates and Triterpenoids ,with the absence of Saponins, Glycosides, Resins, Phenols and Triterpenoids in its water extract .                                                

Results pointed that, the efficiency of Saccharomyces cerevisia in the inhibiting of radial growth of A. flavus and A. parasiticus was 100% at 2 and 3 g/L and 91.60% at 1g/L in the A. flavus and 75.00 and 70.33% at 3 and 2g/L and respectively 56% at 1g/L for A. parasiticus , and the aflatoxin B₁ did not appeared with treatment of A. flavus with 1,2and 3 g/L from Saccharomyces cerevisiae extract while it appeared with treatment of A. parasiticus with 1,2 and 3 g/L from Saccharomyces cerevisiae extract .

Some physical parameters showed that the temperature 30⁰C was the best for fungi growth and their production from afla B₁, where the mean diameter of the colony was 9 cm followed by 20⁰C gaving 2.83 and 3.04 cm for A. flavus and A. parasiticus respectively .

Increasing and decreasing temperature from this rang toxins reduced in the fungal growth as well as their production of Afl B_1.

The best pH for fungal growth was 7.5 whose the no did growth of A. flavus and A. parasiticus was 6.29 and 6.50cm respectively followed pH 9.5 giving 5.09 and 5.29cm for A. flavus and A. parasiticus respectively .On the other hand . No growth was obtained at pH 3.5 . The afla B₁ did not appeared with pH 3.5 , mean while it appeared with pH 5.5 , 7.5 and 9.5 .

There was difference in the dry weight of the above mentioned fungi due to aeration . the incubation with continuous aeration for 3 day was the best compared without aeration .The dry weight in the first treatment was 1.24 and 1.13g for A. flavus and A. parasiticu respectively whereas it was 0.88 and 0.83g in the second treatment respectively . Results also indicated that A. flavus and A. parasiticu had an ability to produce phenolic compounds when they grew on Broth Potato dextrose extract (PDB).