Thesis (M.Sc.) - Cairo University - Faculty of Science - Department of Botany- Microbiology

Among the fungal species isolated from waste water, soil and air around detergent factory (pH 10.5), Aspergillus fumigatus was found to be the most potential proteolytic species. Optimization of cultural condition for maximum protease production using Taghuchi Factorial Design System indicated that the optimum variables in growth media were; Malt extract 20g; Fructose 5 g; Urea 7 mg; Salt solution 1.25 % ;temperature 45{u00BA}C; incubation period, 7 days and pH 9.0; inoculum 3 fungal discs; agitation 150 rpm. Purification of alkaline protease was made in a four-step procedure involving ammonium sulphate precipitation, anion exchange using DEAE Cellulose, gel filtration by Sephadex G-100 and Sephadex G-150 column chromatographies. The apparent molecular weight of the enzyme was determined by SDS-PAGE to be 24 KDa. A. fumigatus protease was found to be thermo-alkalophilic enzyme acting optimally at pH 11 and 50{u00B0}C. The alkaine protease (ALP) inhibited by Na⁺, Cu⁺², Zn⁺², Mg⁺², Fe⁺³, EDTA and Urea but activated by Ca⁺² and Mn⁺²

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