Immobilization of Burkholderia sp. lipase on a ferric silica nanocomposite for biodiesel production.
In this work, lipase produced from an isolated strain Burkholderia sp. C20 was immobilized on magnetic nanoparticles to catalyze biodiesel synthesis. Core-shell nanoparticles were synthesized by coating Fe(3)O(4) core with silica shell. The nanoparticles treated with dimethyl octadecyl [3-(trimethoxysilyl) propyl] ammonium chloride were used as immobilization supporters. The Burkholderia lipase was then bound to the synthesized nanoparticles for immobilization. The protein binding efficiency on alkyl-functionalized Fe(3)O(4)-SiO(2) was estimated as 97%, while the efficiency was only 76% on non-modified Fe(3)O(4)-SiO(2). Maximum adsorption capacity of lipase on alkyl-functionalized Fe(3)O(4)-SiO(2) was estimated as 29.45 mg g(-1) based on Langmuir isotherm. The hydrolytic kinetics (using olive oil as substrate) of the lipase immobilized on alkyl-grafted Fe(3)O(4)-SiO(2) followed Michaelis-Menten model with a maximum reaction rate and a Michaelis constant of 6251 Ug(-1) and 3.65 mM, respectively. Physical and chemical properties of the nanoparticles and the immobilized lipase were characterized by Brunauer-Emmett-Teller (BET) analysis, scanning electron microscope (SEM), and Fourier transform infrared spectroscopy (FT-IR). Moreover, the immobilized lipase was used to catalyze the transesterification of olive oil with methanol to produce fatty acid methyl esters (FAMEs), attaining a FAMEs conversion of over 90% within 30 h in batch operation when 11 wt% immobilized lipase was employed. The immobilized lipase could be used for ten cycles without significant loss in its transesterification activity.
Department of Chemical Engineering, National Cheng Kung University, Tainan 701, Taiwan, ROC.
Dang-Thuan
DT
Tran
Ching-Lung
CL
Chen
Jo-Shu
JS
Chang
D001426:Bacterial Proteins / Q000737:chemistry*; D056804:Biofuels; D019117:Burkholderia / Q000201:enzymology*; D004800:Enzymes, Immobilized / Q000737:chemistry*; D005290:Ferric Compounds / Q000737:chemistry*; D008049:Lipase / Q000737:chemistry*; D053761:Nanocomposites / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry*
D001426:Bacterial Proteins; D056804:Biofuels; D004800:Enzymes, Immobilized; D005290:Ferric Compounds; C000499:ferric oxide; D012822:Silicon Dioxide; D008049:Lipase