title: Effect of metal ions on the hydrolytic and transesterification activities of Candida rugosa lipase.
abstract: In order to study the effect of metal ions on lipase activity, hydrolytic and transesterification activities of Candida rugosa lipase were investigated in presence of alkali (Na⁺ and K⁺), alkaline earth (Ca⁺² and Ba⁺²) and transition (Cr⁺³, Fe⁺³, Co⁺², Cu⁺² and Ni⁺²) metal ions. Maximum enhancement in hydrolytic activity of lipase was observed by Ca⁺², and in transesterification activity by Cr⁺³ and Co⁺². The kinetics of the lipase catalyzed transesterification (methanolysis and ethanolysis) reactions were also studied, and the activation energies of methanolysis and ethanolysis were reduced from 10.16 and 10.24 kcal mol⁻¹, respectively, to 5.41 and 7.55 kcal mol⁻¹, respectively, when reactions were performed in presence of Co⁺². Thus, in lipase catalyzed transesterification Cr⁺³ or Co⁺² could be added to the assay in order to produce the biodiesel in relatively shorter reaction duration.
authors.affiliation: School of Chemistry and Biochemistry, Thapar University.
authors.forename: Madhu
authors.initials: M
authors.lastname: Katiyar
authors.forename: Amjad
authors.initials: A
authors.lastname: Ali
mesh_terms: D056804:Biofuels; D002175:Candida / Q000201:enzymology*; D003369:Cottonseed Oil / Q000737:chemistry* / Q000378:metabolism*; D004735:Energy Transfer; D004789:Enzyme Activation / Q000187:drug effects; D004951:Esterification / Q000187:drug effects; D006868:Hydrolysis / Q000187:drug effects; D007477:Ions; D008049:Lipase / Q000737:chemistry / Q000378:metabolism*; D008672:Metals, Alkali / Q000494:pharmacology*; D008673:Metals, Alkaline Earth / Q000494:pharmacology*; D019216:Metals, Heavy / Q000494:pharmacology*
chemical_list: D056804:Biofuels; D003369:Cottonseed Oil; D007477:Ions; D008672:Metals, Alkali; D008673:Metals, Alkaline Earth; D019216:Metals, Heavy; D008049:Lipase