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

Biodegradation of agricultural wastes by microorganisms is an acceptable method which results in useful end product andreduces environmental pollution. Two agricultural wastes (sugar cane bagasse and rice straw) weresubjected to biodegradation. One hundred and forty microbial isolates (fungi, actinomycetes and bacteria) were isolated from different sources, were screened for cellulase production on carboxymethylcellulose (CMC) agar. The most active (67) selected isolates were secondary screenedfor their ability for production of cellulolytic enzymes using alkali pretreated sugar cane bagasse and rice straw as sole carbon sources. Three enzymatic activities namely, (FPase, CMCase and xylanase) were determined. Microbial isolates exhibited high variation in their cellulolytic activity. Based on the results of secondary screening experment, the highly active seven microbial strains (3 fungi, 2 actinomycetes and 2bacteria) were further investigated for their ability to degrade the untreated as well as alkali pretreated sugar cane bagasse and rice straw through solid state fermentation (SSF) experiment. After 15-30 days of fermentation, cellulolytic activity and physicochemical parameters (EC, pH, weight loss %, N% and C/N ratio) of fermented substrates were evaluated. The 7 microbial strains showed variation in their ability for degradation of agricultural wastes depending on the type of agricultural wastes and the duration of fermentation. F14 (Aspergillus terreus) gave the highest FPase activity on both agricultural wastes. While, the highest CMCase activities were obtained by F53 (penecilliumchrysogenum) to be 4.99 and 5.97U/g on alkali pretreated sugar cane bagasse and rice straw, respectively

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