Biocompatible cellulose nanocrystals as supports to immobilize lipase

Abstract

Cellulose nanocrystals (CNCs) are rod-like cellulose nanomaterials that can be economically prepared from various cellulosic materials by the elimination of amorphous regions of cellulose. CNCs can be used as supports to immobilize enzymes because of their inherent biocompatibility, high specific-surface area, and exceptional mechanical properties. In this study, CNCs obtained from cotton linter cellulose (CLC) and bacterial cellulose (BC) were used as supports to immobilize Candida rugosa lipase. The protein loading and immobilization yield of the lipase immobilized onto the CNC obtained from CLC (CNC⿿CLC) were 1.8 and 2.2 times higher, respectively, than those of the lipase immobilized onto CLC. The lipase immobilized onto CNC⿿CLC showed significantly enhanced thermal stability. The half-life time of the immobilized lipase during incubation at 60°C was 27 times higher than that of free lipase. The lipase immobilized onto CNC⿿CLC also showed increased pH stability at an alkaline pH. The residual activity of the immobilized lipase after 5h incubation at pH 10 was 8.8 times higher than that of free lipase. In addition, the lipase immobilized onto CNC⿿CLC was able to perform homogeneous-like biocatalysis without shaking or agitation because the immobilized lipase remained well-dispersed during the aqueous reaction. The CNCs as enzyme supports have many potential applications in the biomedical, bioelectronic, and biocatalytic fields.