Tamires Carvalho; Adejanildo Pereira; Priscilla V. Finotelli; Priscilla F. F. Amaral
Abstract
Magnetite nanoparticles have unique properties including superparamagnetism and low toxicity. They have been used as supports for immobilization of enzymes because of the advantage including easy separation and effective recycle under external magnetic field. Therefore, the present study aimed at developing ...
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Magnetite nanoparticles have unique properties including superparamagnetism and low toxicity. They have been used as supports for immobilization of enzymes because of the advantage including easy separation and effective recycle under external magnetic field. Therefore, the present study aimed at developing a new enzymatic biocatalyst from the immobilization of Yarrowia lipolytica’s (IMUFRJ 50682) lipase on magnetic nanoparticles for its use in free fatty acids and carotenoids extraction from palm oil (Elaeis guineenses). The lipase production conducted in a 4 L benchtop bioreactor generated a crude enzyme extract with hydrolytic p-nitrophenyl laurate activity of 58 U/ml after 24 h. Lipase was immobilized by adsorption on magnetite nanoparticles (Fe3O4). The crude enzymatic extract, both free and immobilized, were used in the hydrolysis of palm oil. Temperature, reaction time and substrate ratio (water/palm oil) were evaluated in a central composite experimental design. The initial concentration of fatty acids and carotenoids present in palm oil obtained via traditional extraction (using organic solvents) were 82.45% and 1892.3 mg/kg, respectively. Using crude lipase extract immobilized in nanoparticles, after 120 min, temperature of 24°C and water/oil ratio of 2, it was possible to obtain similar values, with the advantage of easily removing the catalyst from reaction media and reusing it.
Cansu Ulker; Nurefsan Gokalp; Yuksel Avcibasi Guvenilir
Abstract
In the present study, ring opening polymerization of ε-caprolactone was performed by a novel enzymatic catalyst, Candida antarctica lipase B (CALB) immobilized on a modified silica-based material by physical adsorption. Molecular weight distributions and chain structures were compared by using ...
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In the present study, ring opening polymerization of ε-caprolactone was performed by a novel enzymatic catalyst, Candida antarctica lipase B (CALB) immobilized on a modified silica-based material by physical adsorption. Molecular weight distributions and chain structures were compared by using gel permeation chromatography (GPC) and hydrogen nuclear magnetic resonance ( 1 H NMR) analysis, respectively. In addition, for the determination of thermal properties, thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC) were performed. Scanning electron microscopy (SEM) was applied to observe the surface structure of the polymer. Effects of temperature, reaction time, and enzyme concentration on molecular weight of poly (ε-caprolactone) (PCL) were investigated and optimum conditions for the ring opening polymerization of ε-caprolactone via this new immobilized enzyme were obtained. Highest molecular weight was achieved as 14000 g/mol at the end of 48 hours at 60 ÌŠ C. Moreover, considerably high molecular weights were successfully reached at lower temperatures by this novel enzyme, which makes this process low energy consuming besides being environmentally friendly. It is suggested that, CALB immobilized on a modified silica-based material by physical adsorption may be a great alternative for widely used commercial enzyme, Novozyme 435. This work also makes possible a new route for polymer synthesis.