title: Efficient transformation of grease to biodiesel using highly active and easily recyclable magnetic nanobiocatalyst aggregates.
abstract: Green and efficient production of biodiesel (FAME) from waste grease containing high amount of free fatty acid (FFA) was achieved by using novel magnetic nanobiocatalyst aggregates (MNA). Thermomyces lanuginosus Lipase (TLL) and Candida antarctica Lipase B (CALB) were covalently immobilized on core-shell structured iron oxide magnetic nanoparticle (80 nm), respectively, followed by freeze-dry to give MNA (13-17 μm) with high yield (80-89%) and high enzyme loading (61 mg TLL or 22 mg CALB per gram MNA). MNA TL showed the best performance among immobilized enzymes known thus for the production of FAME from grease (17 wt.% FFA) with methanol, giving 99% yield in 12 h (3.3 wt.% catalyst). MNA TL was easily separated under magnetic field and reused, retaining 88% productivity in 11th cycle. MNA CA converted >97% FFA in grease (17 wt.% FFA) to FAME in 12 h (0.45 wt.% catalyst), being useful in two-step transformation of grease to biodiesel.
authors.affiliation: Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore 117576, Singapore.
authors.forename: Thao P N
authors.initials: TP
authors.lastname: Ngo
authors.forename: Aitao
authors.initials: A
authors.lastname: Li
authors.forename: Kang W
authors.initials: KW
authors.lastname: Tiew
authors.forename: Zhi
authors.initials: Z
authors.lastname: Li
mesh_terms: D001203:Ascomycota / Q000201:enzymology; D056804:Biofuels; D019149:Bioreactors; D001709:Biotechnology / Q000379:methods*; D001711:Biotransformation / Q000502:physiology; D002175:Candida / Q000201:enzymology; D002849:Chromatography, Gas; D005223:Fats / Q000737:chemistry / Q000378:metabolism*; D005230:Fatty Acids, Nonesterified / Q000378:metabolism*; D005612:Freeze Drying; D058185:Magnetite Nanoparticles; D000432:Methanol / Q000378:metabolism; D014866:Waste Products
chemical_list: D056804:Biofuels; D005223:Fats; D005230:Fatty Acids, Nonesterified; D058185:Magnetite Nanoparticles; D014866:Waste Products; D000432:Methanol
keywords: Biodiesel; Enzyme catalysis; Free fatty acid; Grease; Magnetic nanoparticles