الفهرس 
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Abstract
This work aimed to study the association of mycoflora with different types of medicinal plants, their screening for aflatoxins producing ability, aflatoxins occurrence in the medicinal plant samples and attempts to control or detoxify aflatoxins production using some antimicrobial agents and chemicals. Thirty six species and 1 variety belonging to twelve genera were identified throughout this investigation. The highest contaminated samples were those of linseed followed by anise while guava was the least one. One hundred and fifty one fungal isolates belonging to Aspergillus flavus group were screened for aflatoxins production by TLC analysis and their concentrations were quantitatively calculated using HPLC, 67 isolates (44.4%) were found to be toxigenic. Out of 30 medicinal plant samples screened, 19 samples only (63.3%) were found to be contaminated with aflatoxins. The highest content of aflatoxins was detected in ammi followed by anise and black pepper. The three natural substrates which were the most contaminating medicinal plants with aflatoxins and also three fungal isolates were selected for further studies. Temperature affected the growth and aflatoxin production by the selected isolates in the culture media whereas; the most favorable temperature for the maximum growth ranged from 30°C to 35°C and for aflatoxins production ranged from 25°C to 30°C while the optimum temperature for aflatoxins production in the selected medicinal plants was at 25°C. With regard to the effect of moisture content on aflatoxins production in the selected medicinal plants, it was found that the maximum production of aflatoxins was at 10%.The growth and aflatoxins production by the tested isolates was decreased with increasing ozone concentrations and prolonged treatment time showing the lowest growth and the lowest concentration of aflatoxins at 70 ppm after exposure time 10 min while a complete inhibition was occurred after exposure time 15 min. Also, use of different concentrations of Zingiber officinale and Lepidium sativum oils had a curical effect on growth and aflatoxins production by the tested isolates in the culture media and in the selected medicinal plants. It was also found that the addition of propionic and benzoic acids had an obvious effect on growth and aflatoxins production by the tested isolates in the culture media.