title: 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.
authors.affiliation: Department of Chemical and Materials Engineering, University of Kentucky, Lexington, 40506, USA.
authors.forename: J
authors.initials: J
authors.lastname: Liu
authors.forename: J
authors.initials: J
authors.lastname: Wang
authors.forename: L G
authors.initials: LG
authors.lastname: Bachas
authors.forename: D
authors.initials: D
authors.lastname: Bhattacharyya
mesh_terms: D000345:Affinity Labels / Q000737:chemistry; D002384:Catalysis; D002482:Cellulose; D004795:Enzyme Stability; D004800:Enzymes, Immobilized / Q000378:metabolism*; D008567:Membranes, Artificial; D009842:Oligopeptides; D010455:Peptides / Q000737:chemistry; D020860:Subtilisin / Q000378:metabolism*; D013499:Surface Properties; D013696:Temperature; D013997:Time Factors
chemical_list: D000345:Affinity Labels; D004800:Enzymes, Immobilized; D008567:Membranes, Artificial; D009842:Oligopeptides; D010455:Peptides; D002482:Cellulose; C085706:FLAG peptide; D020860:Subtilisin