الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Carbofuran and diazinon are used for controlling pests in areas of intensive cultivation of economic valuable
crops in Egypt. A series of experiments was conducted to ccamine short-term changes in soil bacterial and fJngal b
populations after commercial carbofuran or diazinon 11 application. Soil enrichment culture technique was used to isolate carbofuran or diazinon degraders which, can be used
to decontaminate pesticide polluted soils or sites. The most active isolates were completely identified as Aspergillus flavus, A.niger, A.terreus, Fusarium sambucinum and F.dimerum.
Aspergillus jlavus and A.terreus showed highest
ability to degrade diazinon even at high concentration (7500p.p.m). Electron microscopy studies on the most active diazinon degraders showed that diazinon affected mainly on sporulation process and hypha!formation.
Studying the physiological conditions effective for the diazinon degradation by A. flavus and A. terreus, the optimum pH was found to be 7, incubation temperature
30°C for seven days. Salinity over 3% highly decreased the diazinon degradation while the aerobic condition favorites it. selected fungal isolates were able to utilize diazinon as sole source ofC, N, P or S but their ability was maximized in complete medium containing all nutritional components plus diazinon.
By following the degradation pathway of diazinon by selected fungal isolates using GC/MS analysis,
2-isopropyl-4-methyl-6-pyrimidone and2-(1-hydroxymethyl
ethyl)-4-pyrimidone were accumulated in the medium as metabolites.
Increasing doses of gamma radiation highly affected
the viability of both tested isolates. The D10 value of Ajlavus was 0.64 kGy while it was 0.72 kGy for A. terreus. Unfortunately, all selected gamma irradiated isolates of Ajlavus and A. terreus exhibited less diazinon degradation abilities.