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

Xylanase is one of the most important enzymes consumed industrially and biotechnologically as hydrolyzing xylan that is widely spread among agro wastes accounting for about one-third of the renewable organic carbon on Earth Xylanases are produced by many organisms. This study was carried out to produce xylanase enzymes from marine bacteria to improve the production and study the effect of the produced enzyme on lignocellulosic agriculture waste to be used in industrial and biotechnological applications. By identification of the selective strain by using 16sRNA, the isolate was a new strain called Bacillus subtilis AKM1 and has the accession number MK377251.The optimum culture conditions for xylanase production from Bacillus subtilis AKM1 were as follows incubation period (48 hr), initial pH (7.0), agitation speed (100 rpm), incubation temperature(40{u00B0}C). After the purification, xylanase showed maximal activity at 50 {u00B0}C and pH 7.0. metal ions as Mn²⁺, Ca²⁺, and Fe²⁺ increased the residual activity by increasing the concentration, while Ag+, SDS, and EDTA completely inhibited the activity at higher concentrations. the molecular weight was 34 KDa , Km 0.044 mM and Vmax 22.222. Xylooligosaccharides produced by enzymatic hydrolysis using the purified xylanase showed antimicrobial activity, antioxidant activity, and anti-tumor activity against breast and colon cancer cells

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