Study On Enzymatic Characteristic And Co-immobilization Of Cellulase Xylanase And Laccase

Our annual production of straw is over 700 million tons, about 20%-30% of the worldamounts.Jilin annual use of straw is about 39.6 million tons, and comprehensive utilization rate is of only 35 percent. Most were burned. it is a waste of the valuable natural resourcesand pollution of the environment, which has become the important reasons of haze.Currently, the use of straw includesfeed, fertilizer, binder, materials and energy. And the material and energy arethe higher value-added applications.Because of the main component are the straw cellulose, hemicellulose, and lignin, so it is difficult to effectively degradeby using single enzyme. And multiple segments enzyme digestion the cost too high and couldn’t meet the industrial application.Multi-enzyme common immobilization is a new technique in recent years, and plays multi-enzyme synergies.It can be achieved step conversion of substrate to product and many other advantages, whichget more and more attention.The multi-enzyme of Co-immobilized system in the cascade reaction can increase reactant concentrations of the enzyme around, and combine catalytic properties of different enzymes together.Thus certain disturbances can be excludedtoimprovethe overall catalytic efficiency of the enzyme.In addition, thre co-immobilized system of enzyme also applies to coenzyme regeneration during the reaction, which greatly reducesthe cost of large-scale bio-catalyzed reactions. Multi-enzyme immobilization technology is common to consider the structure and function of a single enzyme, but also need to study to maintain optimum conditions for each enzyme activity and stability.In this paper, cellulase, xylanase and laccase immobilization process are research-based.The p H-sensitive and reversible soluble polymer Eudragit L-100 was selected as a carrier. Immobilized cellulase, xylanase and laccase were prepared with the application of physical adsorption. And enzymatic properties of immobilized enzyme were preliminarily studied. The results were as follows:1. Enzyme activity was used as index to study cellulase, xylanase and laccase enzymatic properties. and to provide basic data for the subsequent immobilization studies. The results showed: for the Cellulase enzyme,the reaction optimum wasp H 4, the temperature was 50 ℃, reaction time was 30min;for the Xylanase enzymaticthe reaction optimum was p H 6, the reaction temperature was 50 ℃;for the Laccase optimum the reaction optimum was p H 6, the temperature was 50 ℃, reaction time was 30 min.2. Cellulase, xylanase and laccase were immobilized and studiedthe enzymatic properties of the immobilized enzyme.The results showed: for the Immobilized cellulase enzyme,the reaction optimum p H was 5, the temperature was 60 ℃, reaction time was 40min;for the Immobilized xylanase,the optimum p H was 5, the temperature was 50 ℃, reaction time was 40min;for the Immobilized laccase,the reaction optimum p H was 4, and the reaction time was 40 min.3. Effect of different carrier concentration on total immobilization rate ofcellulase, xylanase and laccase was studied.The results showed: When the carrier concentration was1.6%, the fixed rate reacheda maximum of three enzymes, and cellulase enzyme immobilization rate was71.36%; xylanase fixed rate was66.79%; Immobilization rate was62.98%.4. Effects of different EDC concentrations on immobilization rate of free cellulase, xylanase and laccase. The results showed that: when the EDC concentration was0.1%, the fixed rate reacheda maximum of three enzymes. Cellulase enzyme immobilization was 74%; xylanase fixed rate was64%; Immobilization ratewas 58%.5. The conclusion of analyzingreversible soluble of the carrier:when p H was about 4.0, the carrier relative absorbance was 100%; when the p H value was greater than 5.0, the carrier relative absorbance was0.6. When the p H was about 4.8, the reaction temperature was 60 ℃, reaction time was 40 min, the carrier and EDC concentration was1.6% and 0.1% respectively;immobilization rates of cellulase, xylanase and laccase were 50.86 %, 36.90% and 25.93% respectively.