Cross-linked enzyme aggregates (CLEAs) of cellulase with improved catalytic activity, adaptability and reusability

In this study, cross-linked cellulase aggregates (C-CLEAs) were synthesized by precipitation of cellulase with ammonium sulfate and then cross-linking with glutaraldehyde. The results revealed that the optimal pH of C-CLEAs shifted toward a more acidic environment by 2.0 pH units, and the optimal temperature shifted toward higher temperature by 20 °C after immobilization. The half-life (t_1/2) and inactivation energy (E_d) values of the C-CLEAs were 5.98 times and 1.93 times than that of free cellulase, respectively. Moreover, the C-CLEAs can also maintain about 65.22% of activity after 10 cycles and 63.03% of activity after storage for 56 days at 4 °C. Enzymatic hydrolysis of carboxymethylcellulose sodium and corncob in C-CLEAs system verified that the C-CLEAs performed better than free cellulase (P < 0.01).