title: Quick and low cost immobilization of proteinases on polyesters: Comparison of lactobacilli cell-envelope proteinase and trypsin for protein degradation.
abstract: Cell-envelope proteinases (CEPs) are a class of proteolytic enzymes produced by lactic acid bacteria and have several industrially relevant applications. However, soluble CEPs are economically unfavorable for such applications due to their poor stability and lack of reusability. In a quest to prepare stable biocatalysts with improved performance, CEP from Lactobacillus delbrueckii subsp. lactis 313 and trypsin (as a model enzyme) were immobilized onto nonwoven polyester fabrics in a three-step protocol including ethylenediamine activation and glutaraldehyde crosslinking. Immobilization gave protein loading yields of 21.9% (CEP) and 67.7% (trypsin) while residual activity yields were 85.6% (CEP) and 4.1% (trypsin). The activity of the immobilized enzymes was dependent on pH, but was retained at elevated temperatures (40-70 °C). An increase in Km values was observed for both enzymes after immobilization. After 70 days of storage, the immobilized CEP retained ca. 62% and 96% of initial activity when the samples were stored in a lyophilized form at -20 °C or in a buffer at 4 °C, respectively. Both immobilized CEP and trypsin were able to hydrolyze proteins such as casein, skimmed milk proteins and bovine serum albumin. This immobilization protocol can be used to prepare immobilized biocatalyst for various protein degradation processes.
authors.affiliation: Department of Chemical Engineering, Monash University, Clayton, VIC 3800, Australia.
authors.forename: Dominic
authors.initials: D
authors.lastname: Agyei
authors.affiliation: Department of Chemical Engineering, Monash University, Clayton, VIC 3800, Australia.
authors.forename: Shaun
authors.initials: S
authors.lastname: Tambimuttu
authors.affiliation: Department of Chemical Engineering, Monash University, Clayton, VIC 3800, Australia.
authors.forename: Bhuvana
authors.initials: B
authors.lastname: Kasargod
authors.affiliation: Materials Science and Engineering, Commonwealth Scientific and Industrial Research Organization, Bayview Avenue, Clayton 3168, Australia.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Gao
authors.affiliation: Department of Chemical Engineering, Monash University, Clayton, VIC 3800, Australia. Electronic address: lizhong.he@monash.edu.
authors.forename: Lizhong
authors.initials: L
authors.lastname: He
mesh_terms: D004591:Electrophoresis, Polyacrylamide Gel; D004800:Enzymes, Immobilized / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007778:Lactobacillus / Q000201:enzymology*; D008855:Microscopy, Electron, Scanning; D010447:Peptide Hydrolases / Q000378:metabolism*; D011091:Polyesters / Q000378:metabolism*; D059748:Proteolysis; D013696:Temperature; D014357:Trypsin / Q000378:metabolism*
chemical_list: D004800:Enzymes, Immobilized; D011091:Polyesters; D010447:Peptide Hydrolases; D014357:Trypsin
keywords: Cell-envelope proteinase; Enzyme immobilization; Lactobacilli; Polyester fabric; Protein degradation