Lipase immobilization on Polysulfone globules and their performances in olive oil hydrolysis (original) (raw)
Related papers
Polymer Bulletin, 2010
The advancement of membrane research closely relates to the activities of 'immobilization of enzymes'. The modification of polymeric membrane surfaces according to tailor-made specifications is considered an art and useful in this arena. In this study, lipase is immobilized on Polyvinyl alcohol photomodified Polysulfone (PS-PVA) membranes. The maximum immobilization (1.48 mg/cm 2 ) for PS-PVA membranes is achieved. The amount of immobilized lipase directly relates on the PVA content on the membrane. Scanning Electron Microscope and X-ray diffraction patterns show the evidences of lipase immobilization on membranes. The hydrolytic performances of lipase immobilized PS and PS-PVA-glu membranes for olive oil are studied. The free fatty acid (FFA %) and acid value (AV) parameters are determined by titrimetic analysis (1.53 and 3.04 for PS-PVA-glu) and compared with esterification GC-mass analysis data. The K m and V max values are 105 mM and 0.9 mM/min for lipase immobilized on PS-PVA-glu and 153.8 mM and 0.51 mM/min for lipase on PS. The reusability feature shows the lipase immobilized on PS-PVA-glu matrix have better stability (10.7% decrease) compared to lipase immobilized on PS matrix (33.3% decrease) after five cycles.
International Journal of Biological Macromolecules, 2008
In the present study, lipase was immobilized via glutaraldehyde crosslinking on the polysulfone and polyether sulfone asymmetric membranes. The results indicated that the overall immobilization of lipase is related to the hydrophobicity of the membrane material and thus higher immobilization is achieved for polysulfone membrane. The evidence of immobilization is done by XRD, SEM, contact angle and porometric studies. Hydrolytic activity of lipase in immobilized form is determined by hydrolyzing olive oil and compared with hydrolytic activity of free lipase. The effect of different reaction parameters viz., temperature, pH, substrate concentration, and incubation time on the lipase activity is investigated. The observed maximum reaction rate (V max ) and Michaelis-Menten constant (K m ) of polysulfone and polyether sulfone is determined.
Lipase immobilized by different techniques on various support materials applied in oil hydrolysis
Journal of the Serbian Chemical Society, 2005
Batch hydrolysis of olive oil was performed by Candida rugosa lipase immobilized on Amberlite IRC-50 and Al2O3. These two supports were selected out of 16 carriers: inorganic materials (sand, silica gel, infusorial earth Al2O3), inorganic salts (CaCO3, CaSO4), ion-exchange resins (Amberlite IRC-50 and IR-4B, Dowex 2X8), a natural resin (colophony), a natural biopolymer (sodium alginate), synthetic polymers (polypropylene, polyethylene) and zeolites. Lipase immobilization was carried out by simple adsorption adsorption followed by cross-linking, adsorption on ion-exchange resins combined adsorption and precipitation, pure precipitation and gel entrapment. The suitability of the supports and techniques for the immobilization of lipase was evaluated by estimating the enzyme activity, protein loading immobilization efficiency and reusability of the immobilizates. Most of the immobilizates exhibited either a low enzyme activity or difficulties during the hydrolytic reaction. Only those p...
Selection of hydrophobic membranes in the lipase-catalyzed hydrolysis of olive oil
Journal of Membrane Science, 1998
A hydrophobic membrane (HVHP, polyvinylidene di¯uoride) was selected out of HVHP, PTHK and PTGC (polysulfone) membranes to immobilize Candida rugosa lipase by physical adsorption in the hydrolysis of olive oil in a stirred diffusion cell. A previous model that assumed the Michaelis±Menten kinetics and Langmuir adsorption isotherm for the adsorbed lipase was used to interpret the variation of initial hydrolysis rates with enzyme and substrate concentrations. Replacing the aqueous phase by a fresh buffer, with or without containing partially deactivated lipases, during the reaction did not affect the enzyme activity for the adsorbed lipase. Moreover, the same enzyme performance was obtained when a fresh and a regenerated membrane was used as the carrier in the membrane reactor.
Hydrolysis of Fish Oil by Lipases Immobilized Inside Porous Supports
Journal of the American Oil Chemists' Society, 2011
A new assay was designed to measure the release of omega-3 acids [eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)] from the hydrolysis of sardine oil by lipases immobilized inside porous supports. A biphasic system was used containing the fish oil dissolved in the organic phase and the immobilized lipase suspended in the aqueous phase. The assay was optimized by using a very active derivative of Rhizomucor miehei lipase (RML) adsorbed onto octyl-Sepharose. Standard reaction conditions were: (a) an organic phase composed by 30/70 (v:v) of oil in cyclohexane, (b) an aqueous phase containing 50 mM methyl-cyclodextrin in 10 mM Tris buffer at pH 7.0. The whole reaction system was incubated at 25°C. Under these conditions, up to 2% of the oil is partitioned into the aqueous phase and most of the 95% of released acids were partitioned into the organic phase. The organic phase was analyzed by RP-HPLC (UV detection at 215 nm) and even very low concentrations (e.g., 0.05 mM) of released omega-3 fatty acid could be detected with a precision higher than 99%. Three different lipases adsorbed on octyl-Sepharose were compared: Candida antarctica lipase-fraction B (CALB), Thermomyces lanuginosa lipase (TLL) and RML. The three enzyme derivatives were very active. However, most active and selective towards polyunsaturated fatty acids (PUFA) versus oleic plus palmitic acids (a fourfold factor) was CALB. On the other hand, the most selective derivatives towards EPA versus DHA (a 4.5-fold factor) were TLL and RML derivatives.
Journal of Fermentation and Bioengineering, 1995
Hydrolysis of olive oil in isooctane by lipase from Candida cylindracea in an aqueous solution was carried out in a polydispersed emulsion system prepared by a homogenizer and in a monodispersed emulsion system prepared by the shirasu-porous-glass (SPG) membrane emulsification method. An emulsion system consisting of both SDS and PVA at pH 7.8 was best suited for the reaction. In the monodispersed emulsion, the droplet diameter was controlled by the pore diameter of the SPG membrane to give droplets with a narrow diameter distribution range. The rate of hydrolysis was at&ted by the concentrations of olive oil and lipase, the interfacial area and the emulsion droplets diameter. The kinetic data were interpreted by the interfacial reaction model, in which desorption of the product from the interface was the rate determining step. The equilibrium constant of the adsorption of lipase at the interface were very small compared with that obtained in the isothermal adsorption equilibrium of lipase at the interface without a surfactant. The equilibrium constants of the reaction between lipase adsorbed at the interface and olive oil in the organic phase were nearly of the same order as those obtained in the Lewis cell and the VibroMixer. The desorption rate constants of the product were very large compared with that in the Lewis cell.
Hydrolysis of olive oil with lipase in a “VibroMixer”
Journal of Fermentation and Bioengineering, 1994
Hydrolysis of olive oil in i-octane with Candida cylindracea lipase in aqueous solution was performed in a VihroMixer reactor. The kinetic data were interpreted by the interracial reaction model, whose rate was controlled by the desorption of the product as shown in a previous study of the Lewis-type transfer cell. The desorption rate constant of the product and the equilibrium constant of the reaction between iipase and olive oil were evaluated using the adsorption parameters of lipase. The desorption rate constant was 1.3 x 103 moi/m2h, which was about 3 × 103 times greater than that observed in the Lewis cell. The desorption rate was suspected to be facilitated by the repeated dispersion and coalescence of the oil phase. The equilibrium constant of the interracial reaction was nearly of the same order as that obtained in the Lewis cell.
Journal of Fermentation and Bioengineering, 1995
Hydrolysis of olive oil in isooctane by lipase from Candida cylindracea in an aqueous solution was carried out in a polydispersed emulsion system prepared by a homogenizer and in a monodispersed emulsion system prepared by the shirasu-porous-glass (SPG) membrane emulsification method. An emulsion system consisting of both SDS and PVA at pH 7.8 was best suited for the reaction. In the monodispersed emulsion, the droplet diameter was controlled by the pore diameter of the SPG membrane to give droplets with a narrow diameter distribution range. The rate of hydrolysis was at&ted by the concentrations of olive oil and lipase, the interfacial area and the emulsion droplets diameter. The kinetic data were interpreted by the interfacial reaction model, in which desorption of the product from the interface was the rate determining step. The equilibrium constant of the adsorption of lipase at the interface were very small compared with that obtained in the isothermal adsorption equilibrium of lipase at the interface without a surfactant. The equilibrium constants of the reaction between lipase adsorbed at the interface and olive oil in the organic phase were nearly of the same order as those obtained in the Lewis cell and the VibroMixer. The desorption rate constants of the product were very large compared with that in the Lewis cell.
Bioprocess Engineering, 1995
The operational stability of the Candida rugosa lipase immobilized in a hydrophilic polyurethane foam was evaluated in consecutive batches for the glycerolysis of olive oil in n-hexane, aimed at the production of monoglycerides. Glycerol controlled the glycerolysis in the system under study, since it is both a substrate and a powerful water binder that reduces the water activity of the reaction medium and of the microenvironment. Two sets of experiments were carried out under different glycerol/triglyceride ratios. After 345 hours of consecutive 23 hours batches no lipase inactivation was observed. List of symbols a w thermodynamic activity of water DG diglyceride (s) FAME fatty acid methyl ester (s) FFA free fatty acid (s) FID flame ionization detector Gly glycerol MG monoglyceride (s) TG triglyceride (s) TLC thin layer chromatography
Journal of Fermentation and Bioengineering, 1996
The hydrolysis rates of olive oil catalyzed by lipase were measured in a reverse micellar system using sodium bis(Z-ethylhexyl) sulfosuccinate (AOT) under various conditions. The maximum activity of lipase in the reverse micelles was obtained between pH 6.3 and 7.3. The dependence of the activity on the water content, WO,was influenced by the concentrations of both AOT and lipase. The activity at W, = 7 decreased with increasing lipase concentration when the AOT concentration was below 100 mol/m3. The stability of the lipase in the micelles decreased with increases in the value of W, and in the concentration of AOT. The hydrolysis reaction catalyzed by lipase in the reverse micelles was interpreted by a reaction model based on the interfaciol reaction between lipase adsorbed at the interface and the substrate in the organic phase. The rate is controlled by the desorption step of free fatty acids into the organic solution. The desorption rate constants of fatty acids produced were independent of the AOT concentration at a 6zed W,, and were of nearly the same order of magnitude as that obtained in the emulsion system.