Activity Studies of Immobilized Subtilisin on Functionalized Pure Cellulose-Based Membranes

Abstract

The activity of immobilized subtilisin BPN' on pure cellulose-based membrane support was investigated using site-directed and random immobilization approaches. The catalytic activity of site-directed immobilized subtilisin on pure cellulose fiber-based materials was found to be 81% of that in homogeneous solution, while that of randomly immobilized subtilisin was 27%. Pure cellulose membrane supports provided large surface areas for high enzyme loading without diffusional limitations. The activity of immobilized subtilisin on pure cellulose support was more than twice that on a modified polyether sulfone (MPS) membrane, which was attributed to the higher hydrophilicity of cellulose. Immobilized subtilisin maintained its initial activity for 14 days at 4 degrees C and 7 days at 24 degrees C. The immobilized enzyme could resist higher temperature and operate over a wider range of pH without loss of activity. This study showed that pure cellulose fiber-based membranes are well suited for enzyme immobilization and biocatalysis.

Enzyme immobilization on/in polymeric membranes: status, challenges and perspectives in biocatalytic membrane reactors (BMRs)

“…64 Such high enzyme loadings are known to cause molecular crowding, which results in enzyme deactivation. 19,35,65 Although adsorption is caused by rather weak interactions, a lot of enzymes are stabilized by these interactions and their optimal process conditions can be changed by them (Table 3). Stronger interactions can occur when charged compounds are introduced in the membrane.…”

“…These high enzyme concentrations may alter the properties of an enzyme and in the worst case, it can result in enzyme denaturation or active site blocking. 19,35,65 Thus, a part of activity loss is due to the inaccessibility of the immobilized enzyme for the substrate. 23 However, it is also possible that the enzyme activity declines during process operation and this can often be attributed to improper immobilization of the enzymes, which results in enzyme leaching into the permeate or retentate, depending on the size of the enzyme and the MWCO of the membrane.…”

Feasibility of recycled newspaper as cellulose source for regenerated cellulose membrane fabrication

“…Moreover, the regenerated cellulose can be a promising biobased packaging materials as well as for wound dressing . The versatility of cellulose to be applied in various applications is due to its low cost, strong hydrophilicity properties, fascinating structure, biocompatibility, and derivable properties . In recent years, the green comprehensive utilization of cellulose resources has drawn much attention from governments and researchers .…”

Preparation, Characterization, and In Vitro and In Vivo Evaluation of Cellulose/Soy Protein Isolate Composite Sponges

“…C ellulose, the most abundant natural polymer with fascinating structure and properties [1], has been widely used in agriculture, construction, packaging, energy resources, paper-making, feedstuff, drug additives, and biomaterials for many years [1][2][3][4]. In the biomaterial and biomedical engineering fields, due to their biodegradability, biocompatibility, and nontoxicity to cells and tissue [5], cellulose and its derivatives have been fabricated into membranes [6,7], fibers [8], microcarries [9], and sponges [10,11]. The sponges based on cellulose and its derivatives are used mainly as haemostatic agents [12], anti-adhesion agents in surgery [13] and tissue scaffolds [3,14].…”