Preparation and characterization of reusable magnetic combi-CLEA of cellulase and hemicellulase

Cross-linked enzyme aggregate (CLEA) is a technology to overcome the limitation of enzymes for its application in chemical industries. The inability of repeated use of enzymes, stability and ease of separation from reaction mixture limits its applications. Here, magnetic combi-CLEA has been synthesised by adding amino-functionalized magnetic nanoparticles into pectinase ultra-clear (containing pectinases, xylanases and cellulases). Enzymes were precipitated on the surface of amino-functionalized magnetic nanoparticles with ethanol and cross-linked using glutaraldehyde. The structural characterization of magnetic combi-CLEA was studied by Scanning Electron Microscopy. Thermal stability was performed at 70 degrees C for pectinase and 80 degrees C for xylanase and cellulase respectively. Half-life (t(1/2)) of the xylanase, cellulase and pectinase in free form remarkably enhance from 84.51, 29.36, and 25.29 min respectively to 533.07, 187.29 and 147.44 min in magnetic-combi CLEA respectively. Magnetic combi-CLEA can be efficiently reused till 12th cycle after which pectinase, xylanase and cellulase retain 86.45%, 90.3% and 88.62% activity respectively. Using this CLEA preparation bioethanol concentration increases to 1.82-fold as compared to free enzyme, when simultaneous saccharification and fermentation was performed using wheat straw as the substrate. Magnetic combi-CLEA can be used for a variety of industrial applications like food processing, textile industry and bioethanol production.