title: Preparation of reusable bioreactors using reversible immobilization of enzyme on monolithic porous polymer support with attached gold nanoparticles.
abstract: Porcine lipase has been reversibly immobilized on a monolithic polymer support containing thiol functionalities prepared within confines of a fused silica capillary and functionalized with gold nanoparticles. Use of gold nanoparticles enabled rejuvenation of the activity of the deactivated reactor simply by stripping the inactive enzyme from the nanoparticles using 2-mercaptoethanol and subsequent immobilization of fresh lipase. This flow through enzymatic reactor was then used to catalyze the hydrolysis of glyceryl tributyrate (tributyrin). The highest activity was found within a temperature range of 37-40°C. The reaction kinetics is characterized by Michaelis-Menten constant, Km  = 10.9 mmol/L, and maximum reaction rate, Vmax  = 5.0 mmol/L min. The maximum reaction rate for the immobilized enzyme is 1,000 times faster compared to lipase in solution. The fast reaction rate enabled to achieve 86.7% conversion of tributyrin in mere 2.5 min and an almost complete conversion in 10 min. The reactor lost only less than 10% of its activity even after continuous pumping through it a solution of substrate equaling 1,760 reactor volumes. Finally, potential application of this enzymatic reactor was demonstrated with the transesterification of triacylglycerides from kitchen oil to fatty acid methyl esters thus demonstrating the ability of the reactor to produce biodiesel.
authors.affiliation: Beijing Key Lab of Bioprocess, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, China; Department of Chemistry, University of California, Berkeley, California.
authors.forename: Yongqin
authors.initials: Y
authors.lastname: Lv
authors.forename: Zhixing
authors.initials: Z
authors.lastname: Lin
authors.forename: Tianwei
authors.initials: T
authors.lastname: Tan
authors.forename: Frantisek
authors.initials: F
authors.lastname: Svec
mesh_terms: D000818:Animals; D056804:Biofuels; D019149:Bioreactors; D004800:Enzymes, Immobilized / Q000737:chemistry* / Q000378:metabolism; D017743:Equipment Reuse; D004951:Esterification; D005227:Fatty Acids / Q000032:analysis / Q000378:metabolism; D006046:Gold / Q000737:chemistry*; D007700:Kinetics; D008049:Lipase / Q000737:chemistry* / Q000378:metabolism; D053768:Metal Nanoparticles / Q000737:chemistry*; D013552:Swine; D013696:Temperature
chemical_list: D056804:Biofuels; D004800:Enzymes, Immobilized; D005227:Fatty Acids; D006046:Gold; D008049:Lipase
keywords: biodiesel; gold nanoparticles; immobilized enzyme bioreactor; lipase; monolith; porous polymer