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Estolides Synthesis Catalyzed by Immobilized Lipases  [PDF]
Erika C. G. Aguieiras,Cláudia O. Veloso,Juliana V. Bevilaqua,Danielle O. Rosas,M?nica A. P. da Silva,Marta A. P. Langone
Enzyme Research , 2011, DOI: 10.4061/2011/432746
Abstract: Estolides are vegetable-oil-based lubricants obtained from oleic acid or any source of hydroxy fatty acids. In this work, the estolides synthesis from oleic acid and methyl ricinoleate (biodiesel from castor oil), using immobilized commercial lipases (Novozym 435, Lipozyme RM-IM, and Lipozyme TL-IM) in a solvent-free medium was investigated. Acid value was used to monitor the reaction progress by determining the consumption of acid present in the medium. Novozym 435 showed the best performance. Water removal improved the conversion. Novozym 435 was more active at atmospheric pressure. Novozym 435 was reused four times with conversion reaching 15% after the fourth reaction at 80°C. Estolides produced under the reaction conditions used in this work presented good properties, such as, low temperature properties as pour point (?24°C), viscosity (23.9 cSt at 40°C and 5.2 cSt at 100°C), and viscosity index (153). 1. Introduction Estolides are a class of polyesters based on vegetable oils that are formed when the carboxylic acid functionality of one fatty acid reacts at the site of unsaturation of another fatty acid [1] or by covalent ester bonds between hydroxyl moiety of one hydroxyl acid and the carboxyl moiety of another hydroxyl acid molecule [2]. These compounds have a variety of potential applications as greases, plastics, inks, cosmetics, viscosity controller for chocolate, emulsifier in margarine, and lubricants [3–5]. As lubricants, estolides have been developed in order to overcome deficiencies associated with some characteristics of vegetable oils, which are known to have poor thermal oxidative stability, low hydrolytic stability, and poor low temperature properties [6]. These vegetable-oil-based lubricants and derivatives have excellent lubricity and biodegradability properties and currently out-perform the commercially available industrial products such as petroleum-based hydraulic fluids, soy-based fluids, and petroleum oils [6, 7]. The conventional chemical route of estolides synthesis using high temperatures (205–210°C) or strong acids as catalysts leads to a lower selectivity, undesired byproducts, colouring, and malodorours of products and cause corrosion of equipments and produce acid effluent [8]. The enzymatic synthesis of ricinoleic acid estolides using lipases (triacylglycerol ester hydrolases E.C. have been investigated as an alternative to overcome the common problems that occur in a conventional route. Most of lipases act under mild reaction conditions (low temperature and pressures, and neutral pH), which prevent degradation
Enantioselective resolution of (R,S)-1-phenylethanol catalyzed by lipases immobilized in starch films
Hoffmann, Isabel;Silva, Vanessa D.;Nascimento, Maria da G.;
Journal of the Brazilian Chemical Society , 2011, DOI: 10.1590/S0103-50532011000800021
Abstract: lipases from different sources and two mycelium-bound lipases, in a free or immobilized form, in ginger starch film were screened as biocatalysts in the reaction of (r,s)-1-phenylethanol (1) with vinyl acetate and other acylating agents. the effect of various reaction parameters in the resolution of (1) catalyzed by lipase from burkholderia cepacia (bcl) immobilized in ginger starch film was evaluated (acyl donor type, alcohol:acyl donor molar ratio, temperature and organic solvent). the catalytic efficiency of bcl immobilized in polymeric blends of ginger starch and polyethylene oxide (peo), in different compositions, was also studied. vinyl acetate and iso-propenyl acetate furnished the highest conversion (9%) and enantiomeric excess (> 99%) of the (r)-ester. the alcohol:acyl donor molar ratio and temperature optimum were 1:1 and 28 oc, respectively. the mixture of n-hexane/glycerol (9:1 v:v) was the most adequate for this reaction (conversion 23%, e > 200). the ginger starch/peo (7:3 m/m) blend was successfully reused six times consecutively.
Immobilized lipases as practical catalysts
Kne?evi? Zorica D.,?iler-Marinkovi? Slavica S.,Mojovi? Ljiljana V.
Acta Periodica Technologica , 2004, DOI: 10.2298/apt0435151k
Abstract: Attractive features of lipase systems include versatility, substrate selectivity, regioselectivity, enantioselectivity and catalysis at ambient temperatures and pressures. To fully exploit the technical and economical advantages of lipases, it is recommended to use them in an immobilized form to reduce the cost and the poor stability of the free lipase. This paper summarizes various methods of lipases immobilization including covalent attachment to or adsorption on solid supports, encapsulation and entrapment within the membrane and in polymeric matrices. The effects of immobilization conditions on lipase properties and stability of biocatalysts are considered. Applications of immobilized lipases in the feasible reaction system as well as probable future trends in lipase catalyzed process are discussed.
Evaluation of the catalytic activity of lipases immobilized on chrysotile for esterification
Silva, Jane E. S.;Jesus, Paulo C.;
Anais da Academia Brasileira de Ciências , 2003, DOI: 10.1590/S0001-37652003000200003
Abstract: in the present work, the ester synthesis in organic media catalyzed by lipases immobilized on chrysotile was studied. lipases of different sources (mucor javanicus, pseudomonas cepacia, rhizopus oryzae, aspergillus niger and candida rugosa) were immobilized on chrysotile, an inexpensive magnesium silicate, and used for esterification of hexanoic, octanoic and lauric acid with methanol, ethanol, 1-butanol and 1-octanol at 25oc in hexane as solvent. the best results were obtained with mucor javanicus lipase and lauric acid giving yields of 62-97% of ester.
Evaluation of the catalytic activity of lipases immobilized on chrysotile for esterification  [cached]
Silva Jane E. S.,Jesus Paulo C.
Anais da Academia Brasileira de Ciências , 2003,
Abstract: In the present work, the ester synthesis in organic media catalyzed by lipases immobilized on chrysotile was studied. Lipases of different sources (Mucor javanicus, Pseudomonas cepacia, Rhizopus oryzae, Aspergillus niger and Candida rugosa) were immobilized on chrysotile, an inexpensive magnesium silicate, and used for esterification of hexanoic, octanoic and lauric acid with methanol, ethanol, 1-butanol and 1-octanol at 25oC in hexane as solvent. The best results were obtained with Mucor javanicus lipase and lauric acid giving yields of 62-97% of ester.
Kinetic and reactor modelling of lipases catalyzed (R,S)-1-phenylethanol resolution  [PDF]
Chua Lee-Suana,Cheng Kian-Kaib,Lee Chew-Tinb,Mohamad-Roji Sarmidic
Iranica Journal of Energy and Environment (IJEE) , 2010,
Abstract: This study was focused on the development of a kinetic model and a reactor model for the enzymatic resolution of (R,S)-1-phenylethanol. The reaction progress curves catalyzed by immobilized lipases, ChiroCLEC-PC in batch stirred tank reactor were used to develop the kinetic model. The resolution followed Ping-Pong Bi-Bi mechanism with the inhibition of lauric acid, (R,S)-1-phenylethanol and water. The validity of the model was verified by fitting it to another experimental data catalyzed by immobilized lipases, Chirazyme L2, c.-f., C3, lyo at the same reaction conditions. The rate equation was then applied for the development of reactor model in a recirculated packed bed reactor system. The overall effectiveness factor and Peclet number were used to determine the mass transfer and axial dispersion limitation in the reactor performance. The reactor model was verified by fitting it to the larger scale reactor data with the correlation coefficient value more than 0.99.
Comparative performance of microbial lipases immobilized on magnetic polysiloxane polyvinyl alcohol particles
Bruno, Laura Maria;Lima Filho, José Luiz de;Castro, Heizir Ferreira de;
Brazilian Archives of Biology and Technology , 2008, DOI: 10.1590/S1516-89132008000500003
Abstract: microbial lipase from mucor miehei and candida rugosa were immobilized by covalent binding onto magnetized polysiloxane polyvinyl alcohol particles (pos-pva). the resulting immobilized derivatives were evaluated in aqueous solution (olive oil hydrolysis) and organic solvent (butyl butyrate synthesis). higher catalytic activities were found when the coupling procedure was made with m. miehei lipase. immobilized m. miehei lipase also showed a better operational stability and a higher half-life than c. rugosa lipase after the successive batches of esterification. the performance of c. rugosa immobilized derivative was constrained by the low lipase loading used in the immobilizing step. further information regarding the both immobilized derivatives was also obtained through chemical composition (ftir).
Biodiesel production by enzyme-catalyzed transesterification  [PDF]
Stamenkovi? Olivera S.,Lazi? Miodrag L.,Veljkovi? Vlada B.,Skala Dejan U.
Hemijska Industrija , 2005, DOI: 10.2298/hemind0504049s
Abstract: The principles and kinetics of biodiesel production from vegetable oils using lipase-catalyzed transesterification are reviewed. The most important operating factors affecting the reaction and the yield of alkyl esters, such as: the type and form of lipase, the type of alcohol, the presence of organic solvents, the content of water in the oil, temperature and the presence of glycerol are discussed. In order to estimate the prospects of lipase-catalyzed transesterification for industrial application, the factors which influence the kinetics of chemically-catalysed transesterification are also considered. The advantages of lipase-catalyzed transesterification compared to the chemically-catalysed reaction, are pointed out. The cost of down-processing and ecological problems are significantly reduced by applying lipases. It was also emphasized that lipase-catalysed transesterification should be greatly improved in order to make it commercially applicable. The further optimization of lipase-catalyzed transesterification should include studies on the development of new reactor systems with immobilized biocatalysts and the addition of alcohol in several portions, and the use of extra cellular lipases tolerant to organic solvents, intracellular lipases (i.e. whole microbial cells) and genetically-modified microorganisms ("intelligent" yeasts).
Capillary Gas Chromatographic (GC) Monitoring of Chicken Meat Triacylglycerol (TAG) Fractionation and Structured Lipid Synthesis by Using Immobilized Lipases within Sol-Gel Phyllosilicate Matrices
Journal of Food Technology , 2013,
Abstract: The lipase-catalyzed modification of natural fats and oil into structured lipids (SLs) has become a great interest in lipid chemistry investigations. Chicken meat fat was fractionally crystallized from acetone to produce monounsaturated fatty acids-enriched triacylglycerol (MUFA-TAG) fractions and gave satisfactory results (p<0.01). Acetone fractionation at two different temperature (0 and -20 C) and four solute-to-solvent ratios (1:10, 1:20, 1:30, 1:40; chicken fat:acetone; wt/v) were applied (p<0.01). The obtained MUFA-TAG fractions has been exposed to lipase enzyme-catalyzed acidolysis reaction with caprylic acid for produce structured lipid (SL) fractions. Acetone fractionation at -20 C with 1:10 chicken fat /acetone (wt/v) was most effective for enriching of the MUFA and PUFA containing TAG of chicken fat (p<0.01). A rapid Capillary Gas Chromatographic (GC) method was developed the chicken meat triacylglycerol (TAG) fractionation and structured lipid synthesis by using immobilized lipases within sol-gel phyllosilicate matrices. Applied Capillary Gas Chromatographic (GC) procedure was rapid, repeatable and sensitive for the chicken meat triacylglycerol (TAG) fractionation monitoring.
Thermal effect on the microwave assisted biodiesel synthesis catalyzed by lipases
Costa, Ingrid C. R.;Leite, Selma G. F.;Leal, Ivana C. R.;Miranda, Leandro S. M.;Souza, Rodrigo O. M. A. de;
Journal of the Brazilian Chemical Society , 2011, DOI: 10.1590/S0103-50532011001000022
Abstract: the esterification reaction mediated by lipases was investigated applying both microwave irradiation and conventional heating in order to evaluate the existence of nonthermal microwave effects on the biodiesel synthesis. all transformations were conducted at 40oc in both monowave 300 and cem discover instruments that allowed accurate internal reaction temperature measurements with use of fiber-optic probes. the conventional heating experiment was performed in an easymaxtm reactor (mettler-toledo), which also allowed accurate measurement of the internal temperature. the results revealed no difference on the reaction time or yield, differently than indicated by some results in the literature.
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