BACKGROUNDCellulose as a renewable biomaterial has forced attention on the use of cellulose-hydrolyzing enzymes for industrial bioconversion of lignocellulosic materials to glucose. This paper reports immobilization of cross-linked cellulase aggregates (CLEA) on the amine-functionalized Fe3O4@silica core-shell magnetic nanoparticles (MNPs). RESULTSThe optimum pH of the cellulase cocktail upon immobilization (cellulase CLEA-MNP) shifted a little to the acidic side whereas the optimum temperature did not change significantly. The behavior of CMCase activity in the cellulase CLEA-MNP at pH and temperature values higher than the optimum was significantly different compared with free cellulase. Cellulase CLEA-MNP retained about 45% of its maximum activity at pH values higher than 4.8, while free cellulase lost its activity sharply. Immobilized cellulase in contrast to the free form retained about 65% of its maximum activity at 80 degrees C. Cellulase CLEA-MNP had improved thermal stability at 65 degrees C. Operational stability of the immobilized cellulase was also noticeable. After a sharp decrease during two cycles of CMC hydrolysis, cellulase CLEA-MNP retained 30% of its initial activity through six cycles of reuse. CONCLUSIONSimple separation of MNPs from reaction medium and durability of CLEA-MNP composite during repeated use may overcome the major bottleneck against comprehensive applications of cellulase enzymes in industry. (c) 2014 Society of Chemical Industry