الفهرس 
1- IntroductionOnly 14 pages are availabe for public view
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Abstract
Zygomycetes fungal cell wall is a source for chitosan production. In this study, chitosan was produced by the fungal strain (Cunninghamella elegans RCMB 012002). The chitosan produced by the fungal strains Cunninghamella elegans was characterized by degree of deacetylation with 81 % and Molecular weight 92KDa using Gel permeation chromatography (GPC). To maximize the fungal chitosan production, five culture conditions; growth medium, carbon and nitrogen source, pH value and temperature were studied. The results showed higher chitosan yield with wheat bran medium and gave 7gm/l by tested strain. The higher yield of chitosan was obtained when glucose was used as the carbon source for Cunninghamella elegans. The sodium nitrate was the best nitrogen source for C. elegans. The pH 4.0 was the best for C.elegans and 25ºC as optimum temperature. The antimicrobial activity of the produced chitosan against the gram- positive bacteria (Staphylococcus aureus), the gram- negative bacteria (Escherichia coli), Candida albicans and Penicillium expansum was evaluated by using well diffusion method , MIC- test and electron scanning microscopy. Chitosan can build complexes with certain metal ions. Amino group sites are the main reactive groups for metals ions, although hydroxyl groups (especially in the C3 position) may contribute for the adsorption process.