Study On Purification And Immobilization Of Xylanase Of Chaetomium Globosum AS3. 3601, And Its Utilization For Xylooligosaccharide Production

Xylooligosaccharide is a kind of functional oligosaccharide that has enormous potential in many fields including food additives, pharmaceuticals, feed formulations. This dissertation studied the purification and immobilization of Chaetomium globosum AS3. 3601 xylanase which amied to resolve the key problem during industrial production of xylooligosaccharides. The strain Chaetomium globosum AS3. 3601 used could produce enzymatic systems of high activity and high stability in the cane bagasse xylan medium with high amount of xylobilse and xylotriose in enzematic product. Furthermore, the strain was proved safe for taking orally. The contents of dissertation cover xylanase purification in aqueous two-phase system, the screening of immobilizing carriers , the conditions optimizing of more effective carriers, and the application of immobilized enzyme in manufacturing xylooligosaccharide. The result showed that:1. The xylanase from Chaetomium globosum AS3. 3601 was extracted by partitioning in ATPS composed of phosphate and polyethylene glycol (PEG). The effect of PEG molecular mass, the phosphate and NaCl concentrations upon the purification factors and yields of xylanase were investigated by statistical design. The best system studied was that containing 16% PEG2000, 10% phosphate and 12% NaCl with a purification factor of 8.55 and a 90.56% yield of enzyme activity. The purified enzyme preparation showed two protein bands on SDS-PAGE, which suggested the potential application for the technology to partition the native xylanase .2. Xylanase from Chaetomium globosum AS3. 3601 were immobilized on six kinds of carriers in routine conditions. Among them, the xylan-crosslink-chotisan, Eudragit L-100 and Eupergit CM showed excellent results for xylanase immobilization and selected for further optimization of immobilization conditions. There were not reports in our country about xylanase immobilized on the three carriers.3. The conditions for xylanase immobilized on three kinds of carriers were optimized...