Immobilization Of Cellulase By Nanotechnology With γ-Fe₂O₃ And PVA

Cellulase is a set of enzymes which are able to degregate the cellulose togetherly。The free cellulase has high cost of production, low enzyme activity, and liable to inactivate. The immobilized cellulase is firm and easy to recycle. Microemulsion is a good way to preparate immobilized nano-particles. The w/o microemulsion can be formed by choosing proper oil phase,water phase and surfactant. The water phase droplet is just the room where the immobilized nano-particles are grow up. Thus the size of nano particle can be controlled through dominating the size of the micro emulsion's droplet.In this paper two methods of the immobilization of cellulase by microemulsion are explored. First the microemulsified and Freeze-thawing method, systerm PVA-y-Fe2O3 is the framework, than the mixture of PVA-y-Fe2O3 and cellulase act as water phase, silicone oil act as oil phase, all of them disperse to form microemulsion, of which the structure can be fixed by Freeze-thawing. The proportion of PVA and y-Fe2O3 can influence the size and charge of the immobilized cellulase. When the mass ratio is 50, the size is minimum. The residual rate of enzyme activity can achieve to 83.9% when we use surfactant span80 and freeze-thawing onetime.The grain size of the nano partical is about 300nm, MF-cellulase has great ability to tolerant the mechanical shear stress.On the base of MF-cellulase, the method of microemulsified and Glutaraldehyde crosslinked cellulase was further explored.The mixture of PVA-y-Fe2O3 and cellulase act as water phase, silicone oil act as oil phase, glutaral pentanedial act as crosslink agent, oleic acid/sodium oleate act as surfactant, all of them disperse to form microemulsion. The residual rate of enzyme activity can achieve to 46.3%,The grain size of the nano partical is about 300nm which has normal shape and close instruction. The MG-cellulase has great pH stability and high tolerance to the mechanical shear stress.Two methods are use to preparate immobilized cellulase.The grain size of the nano partical is about 300nm. The residual rate of enzyme activity can achieve to about50%, or more. The partical of immobilized cellulase possess high tolerance to the mechanical shear stress. The partical can be recycled easily though magnetic field, as it contains y-...