الفهرس | Only 14 pages are availabe for public view |
Abstract In the present investigation some microorganisms were tested for their abilities to produce inulinase. The fungus Aspergillus niger NRRL3 was found to be the most potent producer for inulinase and therefore it was used throughout this study. The effect of some cultural conditions on the productivity of the enzyme by Aspergillus niger NRRL3 was investigated. Partial purification of enzyme was achieved by fractional precipitation of the crude enzyme by ethanol, acetone and ammonium sulfate. The acetone fraction precipitated at 40% exhibited the highest recovered activity. This fraction was used for the succeeding parts of the work. Chemical modification of enzyme by covalent coupling to soluble polysaccharides has been reported as a common technique for improving its properties especially thermal stability. The enzyme coupled to activated pectin retained the highest recovered and specific activity. The properties of the free and conjugated enzyme were compared. The enzyme was immobilized on insoluble supports by different techniques. The enzyme immobilized on loofa by covalent binding showed the highest immobilization yield and the highest immobilized activity_ The properties of the free and immobilized enzyme were compared. The enzyme was purified using a column ofDEAE-cellulose and the molecular weight of the purified inulinase was determined by SDS-gel electrophoresis. The total carbohydrate contents and amino acid composition of pure enzyme were determined. Inulinase was used for production of fructose by enzymatic hydrolysis of inulin extracted from garlic. |