Functional Stabilization of Cellulase from Aspergillus niger by Conjugation with Dextran-aldehyde

Abstract

The covalent conjugates of cellulase from Aspergillus niger were prepared with various molar ratios by using dextran. The conjugate (n(E)/n(D): 1/5) showed higher activity than purified enzyme at all temperatures after 1 h of incubation and its activity could also be measured at higher temperature. Also, this conjugate lost only 60% activity in 2 h at 70 degrees C in comparison to the purified enzyme, which lost all its activity. In addition, conjugation protected cellulase against denaturation in the presence of sodium dodecylsulfate (residual activity of about 80%) and inactivation by air bubbles (residual activity of about 50% for 4 h).