title: Immobilization of Lactase onto Various Polymer Nanofibers for Enzyme Stabilization and Recycling.
abstract: Five different polymer nanofibers, namely, polyaniline nanofiber (PANI), magnetically separable polyaniline nanofiber (PAMP), magnetically separable DEAE cellulose fiber (DEAE), magnetically separable CM cellulose fiber (CM), and polystyrene nanofiber (PSNF), have been used for the immobilization of lactase (E.C. 3.2.1.23). Except for CM and PSNF, three polymers showed great properties. The catalytic activities (kcat) of the free, PANI, PAMP, and magnetic DEAE-cellulose were determined to be 4.0, 2.05, 0.59, and 0.042 mM/min·mg protein, respectively. The lactase immobilized on DEAE, PANI, and PAMP showed improved stability and recyclability. PANI- and PAMP-lactase showed only a 0-3% decrease in activity after 3 months of vigorous shaking conditions (200 rpm) and at room temperature (25°C). PANI-, PAMP-, and DEAE-lactase showed a high percentage of conversion (100%, 47%, and 12%) after a 1 h lactose hydrolysis reaction. The residual activities of PANI-, PAMP-, and DEAE-lactase after 10 times of recycling were 98%, 96%, and 97%, respectively.
authors.affiliation: College of Bioengineering, Beijing Polytechnic, Beijing 100029, P.R. China.|Department of Chemical and Biochemical Engineering, Chosun University, GwangJu 501-754, Republic of Korea.
authors.forename: Lihua
authors.initials: L
authors.lastname: Jin
authors.affiliation: College of Bioengineering, Beijing Polytechnic, Beijing 100029, P.R. China.
authors.forename: Ye
authors.initials: Y
authors.lastname: Li
authors.affiliation: Key Laboratory of Urban Stormwater System and Water Environment, Ministry of Education, School of Environment and Energy Engineering, Beijing University of Civil Engineering and Architecture, Beijing 100044, P.R. China.
authors.forename: Xiang-Hao
authors.initials: XH
authors.lastname: Ren
authors.affiliation: Department of Chemical and Biochemical Engineering, Chosun University, GwangJu 501-754, Republic of Korea.
authors.forename: Jung-Heon
authors.initials: JH
authors.lastname: Lee
mesh_terms: D004795:Enzyme Stability; D004800:Enzymes, Immobilized / Q000737:chemistry / Q000378:metabolism*; D007700:Kinetics; D043322:Lactase / Q000737:chemistry / Q000378:metabolism*; D057139:Nanofibers / Q000737:chemistry*; D013696:Temperature
chemical_list: D004800:Enzymes, Immobilized; D043322:Lactase
keywords: enzyme immobilization; enzyme recycle; lactase; nanomaterials