| enhanced activity and enantioselectivity of candida rugosa lipase immobilized on macroporous adsorptive resins for ibuprofen resolution. | the lipase from candida rugosa was immobilized on three commercially available macroporous adsorptive resins for kinetic resolution of ibuprofen. one resin, crb02, increased the enzyme activity by 50% to 0.027 g g(-1) min(-1). the deactivation constant (0.19 h(-1)) of the immobilized enzyme was half of that of the native enzyme and the enantioselectivity (e = 29.2) of the immobilized lipase was 2.2 times as much as that of the native lipase for the kinetic resolution of ibuprofen with 1-propanol ... | 2004 | 15200171 |
| alternatives to amphotericin b for candida rugosa infection. | amphotericin b failure is frequently seen in patients with candidaemia caused by candida rugosa. we evaluated amphotericin b, fluconazole, posaconazole and voriconazole as alternative treatments against infection in mice with two isolates of c. rugosa. | 2004 | 15215225 |
| thermal stability enhancements of candida rugosa lipase in ionic liquids. | thermostability of candida rugosa lipase in organic solvents and ionic liquids was studied. during our experiments the aim was to determine if the conversion degree and enzyme half-life are changed, i.e. how to tolerate the enzyme the elevated temperature in various solvents. it was found that the enzyme kept its activity and enantioselectivity much better in ionic liquids than in the traditional organic solvents. | 2003 | 15296180 |
| reversible and strong immobilization of proteins by ionic exchange on supports coated with sulfate-dextran. | new and strong ionic exchange resins have been prepared by the simple and rapid ionic adsorption of anionic polymers (sulfate-dextran) on porous supports activated with the opposite ionic group (deae/manae). ionic exchange properties of such composites were strongly dependent on the size of the ionic polymers as well as on the conditions of the ionic coating of the solids with the ionic polymers (optimal conditions were 400 mg of sulfate-dextran 5000 kda per gram of support). around 80% of the p ... | 2004 | 15296440 |
| effect of fermentation conditions in the enzymatic activity and stereoselectivity of crude lipase from candida rugosa. | different fed-batch cultures of candida rugosa were carried out using oleic acid as the only carbon source. the crude lipases obtained under several operational conditions and downstream processes showed different catalytic activity and isoenzymes ratio. this fact implied that the performance of the lipase produced could be modulated by using different operational fermentation conditions. these powders were compared with commercial lipase from sigma (st. louis, mo) in hydrolysis and synthesis re ... | 1999 | 15304677 |
| characterization and utilization of candida rugosa lipase immobilized on controlled pore silica. | candida rugosa lipase was immobilized by covalent binding on controlled pore silica (cps) using glutaraldehyde as cross-linking agent under aqueous and nonaqueous conditions. the immobilized c. rugosa was more active when the coupling procedure was performed in the presence of a nonpolar solvent, hexane. similar optima ph (7.5-8.0) was found for both free and immobilized lipase. the optimum temperature for the immobilized lipase was about 10 degrees c higher than that for the free lipase. the th ... | 1999 | 15304694 |
| reductive alkylation of lipase: experimental and molecular modeling approaches. | candida rugosa lipase was modified via reductive alkylation to increase its hydrophobicity to work better in organic solvents. the free amino group of lysines was alkylated using propionaldehyde with different degrees of modification obtained (49 and 86%). far-ultraviolet circular dichroism (cd) spectroscopy of the lipase in aqueous solvent showed that such chemical modifications at the enzyme surface caused a loss in secondary and tertiary structure that is attributed to the enzyme unfolding. u ... | 2004 | 15304735 |
| immobilization of lipase from candida rugosa on layered double hydroxides for esterification reaction. | synthesis of layered double hydroxides (ldhs) of zn/al-no3- hydrotalcite (hizan) and zn/al-diocytyl sodium sulfosuccinate (dss) nanocomposite (nazad) with a molar ratio of zn/al of 4:1 were carried out by coprecipitation through continuous agitation. their structures were determined using x-ray diffractometer spectra, which showed that basal spacing for ldh synthesized by both methods was about 8.89 a. an expansion of layered structure of about 27.9 a was observed to accommodate the surfactant a ... | 2004 | 15304759 |
| lipase immobilized on poly(vp-co-hema) hydrogel for esterification reaction. | lipase from candida rugosa was immobilized by entrapment on poly(n-vinyl- 2-pyrrolidone-co-2-hydroxyethyl methacrylate) (poly[vp-co-hema]) hydrogel, and divinylbenzene was the crosslinking agent. the immobilized enzymes were used in the esterification reaction of oleic acid and butanol in hexane. the activities of the immobilized enzymes and the leaching ability of the enzyme from the support with respect to the different compositions of the hydrogels were investigated. the thermal, solvent, and ... | 1999 | 15304777 |
| ethyl oleate synthesis using candida rugosa lipase in a solvent-free system. role of hydrophobic interactions. | the solvent-free esterification reaction of a commercial oleic acid and ethanol was selected as the test reaction for candida rugosa lipase immobilized on polypropylene (pp) at 318 k (initial molar ratio 1:1). adding of water from 0 to 30 wt. % (in gram per gram of fatty acid x 100) and the pretreatment of candida rugosa lipase with polyethylenglycol (peg), octane, and acetone increases the conversion to ethyl esters. the role of hydrophobic interactions of the lipase with pp and peg was studied ... | 2004 | 15360295 |
| secondary structure, conformational stability and glycosylation of a recombinant candida rugosa lipase studied by fourier-transform infrared spectroscopy. | the secondary structure of lipase 1 from candida rugosa, a model system for large monomeric enzymes, has been studied by ftir (fourier-transform infrared) spectroscopy in water and 2h2o. the secondary structure content, determined by the analysis of the amide i band absorption through second derivative and curve fitting procedures, is in agreement with that estimated by x-ray data and predicts, in addition, the existence of two classes of alpha-helices. we have also investigated the enzyme stabi ... | 2005 | 15362976 |
| esterase catalysis of substrate vapour: enzyme activity occurs at very low hydration. | it has been generally accepted that enzyme activity requires a minimal hydration of about 0.2 g h2o g(-1) protein. this fits well with evidence that hydration above this level is associated with the onset of intramolecular motions. the influence of enzyme hydration on the hydrolysis of substrate by candida rugosa lipase b and pig liver esterase was investigated. each enzyme was studied as a powder at various hydration levels, using vapour phase ethyl butyrate as substrate. this procedure allows ... | 2004 | 15450854 |
| [identification of candida albicans using the chromogenic medium albicans id]. | the correct identification of the microrganism is the base for epidemiological studies and treatment of infections. the aim of our study was to evaluate the efficacy of the chromogenic media albicans id (biomerieux, france) in the identification of candida albicans. a total of 190 yeasts strains were evaluated in the study. a rate of 100% of all c. albicans (80) and candida dubliniensis (five) strains exhibited blue color. nevertheless, the blue color was also observed with cultures of candida r ... | 2001 | 15496129 |
| kinetic resolution of ibuprofen catalyzed by candida rugosa lipase in ionic liquids. | candida rugosa lipase-catalyzed esterification of ibuprofen with 1-propanol was conducted in seven ionic liquids and the results were compared with those in isooctane. although the enzyme showed comparable or higher activity in some ionic liquids compared to that in isooctane, only in the case of [bmim]pf6 was the enantioselectivity (e = 24.1) almost twice that (e = 13.0) of isooctane. in another six ionic liquids the enzyme enantioselectivity was much poorer (e = 1.1-6.4). at the same conversio ... | 2005 | 15515047 |
| adsorption and activity of candida rugosa lipase on polypropylene hollow fiber membrane modified with phospholipid analogous polymers. | efforts have recently been made toward the study of interactions of phospholipid with various enzymes. it seems that phospholipids may be directly involved in regulating the enzyme activity. in this work, three phospholipid analogous polymers (paps), containing hydrophobic octyloxy, dodecyloxy, and octadecyloxy groups (abbreviated as 8-pap, 12-pap, and 18-pap, respectively), were tethered on polypropylene hollow fiber microfiltration membrane (pphfmm) to create a biocompatible interface for lipa ... | 2004 | 15518509 |
| computational approach to solvent-free synthesis of ethyl oleate using candida rugosa and candida antarctica b lipases. i. interfacial activation and substrate (ethanol, oleic acid) adsorption. | this paper presents the results of a mm2 study of the adsorption of oleic acid and ethanol/water in the tunnel and active-site models of lipases from candida rugosa and candida antarctica b. the role of an interface polar/no polar in the opening of c. rugosa lipase's lid is also addressed, discussed and analyzed at the level of the conformational changes needed to achieve the lipase open form. the adsorption of oleic acid and alcohols considering c. antarctica b, a lipase not interfacially activ ... | 2004 | 15530053 |
| hydrolytic resolution of (r,s)-naproxen 2,2,2-trifluoroethyl thioester by carica papaya lipase in water-saturated organic solvents. | for the first time, the carica papaya lipase (cpl) stored in crude papain is explored as a potential enantioselective biocatalyst for obtaining chiral acids from their racemic thioesters. hydrolytic resolution of (r,s)-naproxen 2,2,2-trifluoroethyl thioester in water-saturated organic solvents is employed as a model system for studying the effects of temperature and solvents on lipase activity and enantioselectivity. an optimal temperature of 60 degrees c, based on the initial rate of (s)-thioes ... | 2005 | 15543625 |
| protein engineering and applications of candida rugosa lipase isoforms. | commercial preparations of candida rugosa lipase (crl) are mixtures of lipase isoforms used for the hydrolysis and synthesis of various esters. the presence of variable isoforms and the amount of lipolytic protein in the crude lipase preparations lead to a lack of reproducibility of biocatalytic reactions. purification of crude crl improve their substrate specificity, enantioselectivity, stability, and specific activities. the expression of the isoforms is governed by culture or fermentation con ... | 2004 | 15554150 |
| highly active, lipase silicone elastomers. | lipase candida rugosa was entrapped in silicone rubber via condensation-cure room temperature vulcanization of silanol-terminated poly(dimethylsiloxane) with tetraethyl orthosilicate as a crosslinker, to give a highly active silicone-enzyme elastomer. the effect on enzyme activity of addition of water and hydrophilic polymeric moieties based on poly(ethylene oxide) 2 was examined, as were crosslinker concentration, enzyme concentration, and elastomer thickness. it was demonstrated that lipase is ... | 2005 | 15576139 |
| multiple mutagenesis of the candida rugosa lip1 gene and optimum production of recombinant lip1 expressed in pichia pastoris. | candida rugosa lipase, a significant catalyst, had been widely employed to catalyze various chemical reactions such as non-specific, stereo-specific hydrolysis and esterification for industrial biocatalytic applications. several isozymes encoded by the lip gene family, namely lip1 to lip7, possess distinct thermal stability and substrate specificity, among which the recombinant lip1 showed a distinguished catalytic characterization. in this study, we utilized pcr to remove an unnecessary linker ... | 2004 | 15592826 |
| structure and dynamics of candida rugosa lipase: the role of organic solvent. | the effect of organic solvent on the structure and dynamics of proteins was investigated by multiple molecular dynamics simulations (1 ns each) of candida rugosa lipase in water and in carbon tetrachloride. the choice of solvent had only a minor structural effect. for both solvents the open and the closed conformation of the lipase were near to their experimental x-ray structures (c(alpha) rms deviation 1-1.3 a). however, the solvents had a highly specific effect on the flexibility of solvent-ex ... | 2004 | 15597204 |
| unexpected reaction profile observed in the synthesis of propyl laurate when using candida rugosa lipases immobilized in microemulsions based organogels. | 1-propyl laurate synthesis should not be used as standard reaction test of immobilized enzymes in microemulsion-based organogels (mbgs) prepared using lecithin/1-propanol as surfactant when extremely active enzymes with high load are used. in these cases, an anomalous kinetic reaction constant value is observed over short reaction times. such an anomalous profile is strongly dependent on the concentration of catalyst in the crude powder and, consequently, is not appreciated when either commercia ... | 2004 | 15604790 |
| recovery of sterols as fatty acid steryl esters from waste material after purification of tocopherols. | tocopherols are purified industrially from soybean oil deodorizer distillate by a process comprising distillation and ethanol fractionation. the waste material after ethanol fractionation (tc waste) contains 75% sterols, but a purification process has not yet been developed. we thus attempted to purify sterols by a process including a lipase-catalyzed reaction. candida rugosa lipase efficiently esterified sterols in tc waste with oleic acid (oa). after studying several factors affecting esterifi ... | 2004 | 15638248 |
| enzymatic procedures in the preparation of regioprotected d-fructose derivatives. | a combination of different lipases from pseudomonas cepacia, candida antarctica b, candida rugosa and mucor miehei, aided the regioesterification of the free fructose allowing the synthesis of 1,6-di-o-acetyl-d-fructofuranose, 1,4,6-tri-o-acetyl-d-fructofuranose, 1,6-di-o-acetyl-4-o-benzoyl-d-fructofuranose and 1,6-di-o-benzoyl-d-fructofuranose. using c. antarctica b and c. rugosa lipases the alcoholysis of fructose peracetate (alpha, beta-form) has furnished 1,2,3,4-tetra-o-acetyl-alpha-d-fruct ... | 2005 | 15639253 |
| process modeling of the lipase-catalyzed dynamic kinetic resolution of (r, s)-suprofen 2,2,2-trifluoroethyl thioester in a hollow-fiber membrane. | a candida rugosa lipase immobilized on polypropylene powder was employed as the biocatalyst for the enantioselective hydrolysis of (r, s)-suprofen 2,2,2-trifluorothioester in cyclohexane, in which trioctylamine was added as the catalyst to perform in situ racemization of the remaining (r)-thioester. a hollow-fiber membrane was also integrated with the dynamic kinetic resolution process in order to continuously extract the desired (s)-suprofen into an aqueous solution containing naoh. a kinetic m ... | 2004 | 15645310 |
| a supported liquid membrane encapsulating a surfactant-lipase complex for the selective separation of organic acids. | we have developed a novel, lipase-facilitated, supported liquid membrane (slm) for the selective separation of organic acids by encapsulating a surfactant-lipase complex in the liquid membrane phase. this system exhibited a high transport efficiency for 3-phenoxypropionic acid and enabled the selective separation of organic acids due to the different solubilities of the acids in the organic phase and the variable substrate specificity of the surfactant-lipase complex in the liquid membrane phase ... | 2005 | 15645485 |
| on the estimation of the pseudo-stoichiometric matrix for macroscopic mass balance modelling of biotechnological processes. | in this paper we propose a methodology to determine the structure of the pseudo-stoichiometric coefficient matrix kappa in a macroscopic mass balance based model. the first step consists in estimating the minimal number of reactions that must be taken into account to represent the main mass transfer within the bioreactor. this provides the dimension of kappa. then we discuss the identifiability of the components of kappa and we propose a method to estimate their values. finally we present a meth ... | 2004 | 15681276 |
| high-yield conversion of (r)-2-octanol from the corresponding racemate by stereoinversion using candida rugosa. | whole cells of candida rugosa catalyzed the conversion of (r)-2-octanol from the corresponding racemate with the optical purity of 97% e.e. and yield of 92% in 10 h. the product was formed through a stereoinversion involving enantioselective oxidation and asymmetric reduction with 2-octanone as the intermediate. | 2005 | 15685415 |
| continuous monitoring of cholesterol oleate hydrolysis by hormone-sensitive lipase and other cholesterol esterases. | hormone-sensitive lipase (hsl) contributes importantly to the hydrolysis of cholesteryl ester in steroidogenic tissues, releasing the cholesterol required for adrenal steroidogenesis. hsl has broad substrate specificity, because it hydrolyzes triacylglycerols (tags), diacylglycerols, monoacylglycerols, and cholesteryl esters. in this study, we developed a specific cholesterol esterase assay using cholesterol oleate (co) dispersed in phosphatidylcholine and gum arabic by sonication. to continuous ... | 2005 | 15716583 |
| immobilization of candida rugosa lipase on a ph-sensitive support for enantioselective hydrolysis of ketoprofen ester. | candida rugosa lipase (lipase of) was immobilized by covalent binding to a ph-sensitive support showing reversibly soluble-insoluble characteristics with ph change. the immobilized lipase could carry out the enantioselective hydrolysis of ketoprofen ester in a soluble form yet be recovered after precipitation by simply adjusting ph. its activity and enantioselectivity for hydrolysis of 2-chloroethyl ester of ketoprofen were enhanced 1.5-fold and 8.7-fold compared with those of free lipase. after ... | 2005 | 15748766 |
| frequent analytical/experimental problems in lipase-mediated synthesis in solvent-free systems and how to avoid them. | compared with chemical catalysis, enzymatic catalysis is a relatively new topic. experimental work involving lipases deserves careful attention and accurate procedures still need to be implemented. a rapid but careful survey of published data immediately demonstrates that experiments performed under similar conditions with similar reagents have led to very different results. the aim of this work is to point out the importance of accurate and systematic procedures in order to ensure the reproduci ... | 2005 | 15789246 |
| candida rugosa lipase-catalyzed intramolecular o- to n- transacylation of butyryl propranolol in the presence of cyclodextrins. | in the present paper, a novel enzymatic reaction between (r,s)-o-butyryl propranolol (o-bp) and lipase from candida rugosa in the presence of hydroxypropyl-beta-cyclodextrin (hp-beta-cd) is described. under the used condition, lipase catalyzed the intramolecular transacylation of o-bp into n-butyryl propranolol (n-bp). propranolol, the product of the expected hydrolysis reaction, was not detected in the reaction medium. a chiral analysis of the reaction product indicated that lipase showed a pre ... | 2005 | 15801768 |
| enzymatic resolution of (+/-)-5-acetoxy-4-aryl-(2e)-pentenoate derivatives. | enzymatic resolution of six (+/-)-5-acetoxy-4-aryl-(2e)-pentenoate derivatives, compounds 9, 11, 13, 15, 17, and 19 bearing a different aromatic substitution pattern, using lipase of-360 from candida rugosa was carried out. the absolute configurations of all hydrolyzed products and all unchanged acetates were found to be s and r, respectively. moreover, the enantiomeric excess of the enzymatic resolution products from 9, 11, and 13 with the ortho-methoxyl group in the aromatic ring was higher th ... | 2005 | 15863931 |
| wood cellulignin as an alternative matrix for enzyme immobilization. | the objective of this work was to select an efficient methodology for preparing active samples of candida rugosa lipase immobilized in wood cellulignin, to be applied in hydrolysis and ester reactions. for this purpose, lipase was immobilized in the matrix by physical adsorption (pure cellulignin) and covalent binding (activated cellulignin with glutaraldeyde or carbonyldiimidazole [cdi]) in the presence or absence of polyethylene glycol (peg) (molecular mass of 1500 daltons) as stabilizing agen ... | 2005 | 15917604 |
| partially purified carica papaya lipase: a versatile biocatalyst for the hydrolytic resolution of (r,s)-2-arylpropionic thioesters in water-saturated organic solvents. | with the hydrolytic resolution of (r,s)-naproxen 2,2,2-trifluoroethyl thioesters in water-saturated isooctane as a model system, improvements of the specific lipase activity and thermal stability were found when a crude carica papaya lipase (cpl) was partially purified and employed as the biocatalyst. the partially purified carica papaya lipase (pcpl) was furthermore explored as an effective enantioselective biocatalyst for the hydrolytic resolution of (r,s)-profen thioesters in water-saturated ... | 2005 | 15918166 |
| chitosan-tethered poly(acrylonitrile-co-maleic acid) hollow fiber membrane for lipase immobilization. | a protocol was used to prepare a dual-layer biomimetic membrane as support for enzyme immobilization by tethering chitosan on the surface of poly(acrylonitrile-co-maleic acid) (pancma) ultrafiltration hollow fiber membrane in the presence of 1-ethyl-3-(dimethylaminopropyl) carbodiimide hydrochloride (edc)/n-hydroxylsuccin-imide (nhs). the chemical change of the chitosan-modified pancma membrane surface was confirmed with fourier transform infrared spectroscopy and x-ray photoelectron spectroscop ... | 2005 | 15919112 |
| an extracellular carboxylesterase from the basidiomycete pleurotus sapidus hydrolyses xanthophyll esters. | an extracellular enzyme capable of efficient hydrolysis of xanthophyll esters was purified from culture supernatants of the basidiomycete pleurotus sapidus. under native conditions, the enzyme exhibited a molecular mass of 430 kda, and sds-page data suggested a composition of eight identical subunits. biochemical characterisation of the purified protein showed an isoelectric point of 4.5, and ideal hydrolysis conditions were observed at ph 5.8 and 40 degrees c. partial amino acid sequences were ... | 2005 | 15927887 |
| rational strategy for the production of new crude lipases from candida rugosa. | candida rugosa was cultured using different inducers (oleic acid, olive oil, sunflower oil, n-dodecanol and glycerol) as the only carbon source in batch conditions, as well as in several fed-batch fermentations (oleic acid as inducer) at variable feed rate conditions. the n-terminal analysis of each crude lipase revealed that, while the isoenzymes lip2 and lip3 are always secreted (at different proportions depending on the inducer), lip1 was produced only using n-dodecanol (batch conditions) or ... | 2005 | 15928857 |
| characterization of sol-gel bioencapsulates for ester hydrolysis and synthesis. | candida rugosa lipase was entrapped in silica sol-gel particles prepared by hydrolysis of methyltrimethoxysilane and assayed by p-nitrophenyl palmitate hydrolysis, as a function of ph and temperature, giving ph optima of 7.8 (free enzyme) and 5.0-8.0 (immobilized enzyme). the optimum temperature for the immobilized enzyme (50-55 degrees c) was 19 degrees c higher than for the free enzyme. thermal, operational, and storage stability were determined with n-butanol and butyric acid, giving at 45 de ... | 2005 | 15930564 |
| outbreak of candida rugosa mastitis in a dairy herd after intramammary antibiotic treatment. | | 2005 | 15965006 |
| identification of reaction networks for bioprocesses: determination of a partially unknown pseudo-stoichiometric matrix. | in this paper we propose a methodology to determine the structure of the pseudo-stoichiometric coefficient matrix k in a mass balance-based model and to identify its coefficients from a set of available data. the first stage consists in estimating the number of reactions that must be taken into account to represent the main mass transfer within the bioreactor. this provides the dimension of k. then we propose a method to directly determine the structure of the matrix (i.e. mainly its zeros and t ... | 2005 | 15995850 |
| superparamagnetic nanoparticle-supported enzymatic resolution of racemic carboxylates. | candida rugosa lipase immobilized on maghemite nanoparticles demonstrated high stereoselectivity in kinetic resolution of racemic carboxylates and improved long-term stability over its parent free enzyme, allowing the supported enzyme to be repeatedly used for a series of chiral resolution reactions. | 2005 | 16136241 |
| a novel reactive perstraction system based on liquid-core microcapsules applied to lipase-catalyzed biotransformations. | a novel reactive perstraction system has been developed based on liquid-core capsules, involving an enzyme-catalyzed reaction coupled with simultaneous in situ product recovery. lipase-catalyzed reactions, hydrolysis of triprionin and nitrophenyl laurate, were selected to test the system and demonstrate the feasibility of immobilization of enzymes to the membranes of liquid-core capsules and the ability to extract hydrophobic products of the reaction within the capsule core. the lipase from cand ... | 2006 | 16136589 |
| unambiguous detection of astaxanthin and astaxanthin fatty acid esters in krill (euphausia superba dana). | hplc atmospheric pressure chemical ionization (apci)/ms, gc ms, hplc diode array detection (dad), and nmr were used for the identification of astaxanthin and astaxanthin fatty acid esters in krill (euphausia superba dana). matrix solid phase dispersion was applied for the extraction of the carotenoids. this gentle and expeditious extraction technique for solid and viscous samples leads to distinct higher enrichment rates than the conventional liquid-liquid extraction. the chromatographic separat ... | 2005 | 16224962 |
| on-line determination of the total lipolytic activity in a four-phase system using a lipase adsorption law. | lipases have a very well known affinity for organic-aqueous interfaces. a previously developed on-line turbidimetric analyser can only analyse the lipase activity present in the aqueous phase of a culture broth. an adsorption law of langmuir type has been derived to determine the lipolytic activity remaining in the organic-aqueous interface formed between oleic acid and culture broth in candida rugosa lipase production fermentation. in the concentration range of oleic acid (0-8 g.l(-1)) and lipo ... | 1999 | 16232505 |
| preparation of detergent-lipase complexes utilizing water-soluble amphiphiles in single aqueous phase and catalysis of transesterifications in homogeneous organic solvents. | a novel method of preparing detergent-enzyme complexes that can be employed in organic media was developed utilizing newly synthesized water-soluble nonionic gemini-type detergents, n,n-bis(3-d-gluconamidopropyl)-3-(dialkyl-l-glutamatecarbonyl)propanamides (big2cnca: n = 10,12,14,16,18) and n,n-bis(3-d-lactonamidopropyl)-3-(dialkyl-l-glutamatecarbonyl)propanamides (bil2cnca: n = 16,18), and nonionic twin-headed detergents, n,n-bis(3-d-gluconamidopropyl)alkanamides (big1cn: n = 12,14,16,18,delta9 ... | 2000 | 16232923 |
| effect of methanol and water contents on production of biodiesel fuel from plant oil catalyzed by various lipases in a solvent-free system. | methyl esters synthesized from plant oil and methanol by the methanolysis reaction are potentially important as a biodiesel fuel. the methanolysis of soybean oil by lipases from various microorganisms was investigated. several of the lipases were found to catalyze methanolysis in a water-containing system without an organic solvent. the lipases from candida rugosa, pseudomonas cepacia, and pseudomonas fluorescens displayed particularly high catalytic ability. the reaction rates of methanolysis c ... | 2001 | 16232938 |
| modification of lipases with poly(ethylene glycol) and poly(oxyethylene) detergents and their catalytic activities in organic solvents. | the alpha-chymotrypsin-poly(ethylene glycol) complex, which was prepared by lyophilizing an aqueous solution, was found to have high catalytic activity in organic media even when the molar ratio of polymer/enzyme in its preparation stage is unity. in this study, we obtained freeze-dried complexes of lipases and poly(ethylene glycol) or poly(oxyethylene) detergents including newly synthesized gemini-type detergents, and their transesterification activity in organic solvents was evaluated. the fre ... | 2001 | 16233142 |
| enantioselective esterification of racemic ibuprofen in isooctane by immobilized lipase on cellulose acetate-titanium iso-propoxide gel fiber. | lipase (candida rugosa) was entrap-immobilized on cellulose acetate-titanium iso-propoxide gel fiber by the sol-gel method. the immobilized lipase was used for the direct synthesis of (s)-ibuprofen ester from racemic ibuprofen using propyl alcohol as an acyl acceptor in isooctane. the activity of the immobilized lipase was decreased to about 10-20% that of native lipase. however, the reaction was more enantioselective compared to that with native lipase. the stability for repeated use was improv ... | 2002 | 16233173 |
| enhanced enzyme activity and enantioselectivity of lipases in organic solvents by crown ethers and cyclodextrins. | lipases from candida rugosa (crl) and pseudomonas cepacia (pcl) were co-lyophilized with cyclic oligoethers including four crown ethers and nine cyclodextrins (cyds), and their transesterification activity and enantioselectivity in organic solvents were evaluated. the pcl co-lyophilized with each additive showed simultaneously enhanced enzyme activity and enantioselectivity when compared to the native lipase lyophilized from buffer alone; in contrast, such enhancement was not observed for the co ... | 2003 | 16233437 |
| transport of organic acids through a supported liquid membrane driven by lipase-catalyzed reactions. | we have developed a lipase-facilitated supported liquid membrane. lipase-catalyzed reactions were coupled with a supported liquid membrane (slm) to transport organic acids through the slm. we succeeded in the rational transport of organic acids through the slm using lipase-catalyzed reactions and observed that there were differences in the transport behavior of various organic acids due to the substrate specificity of lipase. subsequently, various parameters, such as the alcohol concentration in ... | 2003 | 16233539 |
| structural effects of amphiphiles on candida rugosa lipase activation by freeze-drying of aqueous solution of enzyme and amphiphile. | lipases co-lyophilized with water-soluble gemini-type amphiphiles were found to have high enzyme activity in nonaqueous media without washing out of the amphiphile with anhydrous organic solvent. in this study, we obtained freeze-dried complexes of candida rugosa lipase (crl) with six water-soluble twin glusitol-headed amphiphiles bearing different types of hydrophobic tails, including newly synthesized ones, and their transesterification activity in organic solvent was evaluated. the results in ... | 2003 | 16233568 |
| fabrication and application of enzyme-incorporated peptide nanotubes. | enzyme engineering is a fast-growing field in the pharmaceutical and food markets. for those applications, various substrates have been examined to immobilize and stabilize enzymes. in this report, we examined peptide nanotubes as supports for enzymes. when a model enzyme, candida rugosa lipase, was encapsulated in peptide nanotubes, the catalytic activity of nanotube-bound lipases was increased 33% as compared to free-standing lipases at room temperature. at an elevated temperature, 65 degrees ... | 2005 | 16287245 |
| understanding candida rugosa lipases: an overview. | candida rugosa lipase (crl) is one of the enzymes most frequently used in biotransformations. however, there are some irreproducibility problems inherent to this biocatalyst, attributed either to differences in lipase loading and isoenzymatic profile or to other medium-engineering effects (temperature, a(w), choice of solvent, etc.). in addition, some other properties (influence of substrate and reaction conditions on the lid movement, differences in the glycosylation degree, post-translational ... | 2006 | 16288844 |
| the acetates of p-nitrophenyl alpha-l-arabinofuranoside--regioselective preparation by action of lipases. | all possible di-o-acetates and mono-o-acetates of p-nitrophenyl alpha-l-arabinofuranoside were prepared by chemoenzymatic way using lipases. the 2,3-di-o-acetate was obtained in 90% yield by deacetylation of the primary acetyl group of per-o-acetylated p-nitrophenyl alpha-l-arabinofuranoside by candida cylindracea lipase (ccl) or candida rugosa lipase (lay). the 2,5- and 3,5-di-o-acetates were obtained by acetylation of p-nitrophenyl alpha-l-arabinofuranoside by pseudomonas cepacia lipase (lps-3 ... | 2006 | 16288881 |
| a secreted lipase encoded by lip1 is necessary for efficient use of saturated triglyceride lipids in fusarium graminearum. | a triglyceride lipase gene lip1 was identified in the genome of fusarium graminearum strain ph-1. the predicted protein encoded by lip1 contains 591 amino acid residues with a putative n-terminal signal peptide and shows 57 and 40-44 % identity to a botrytis cinerea lipase and five candida rugosa lipases, respectively. yeast cells overexpressing lip1 showed lipolytic activity against a broad range of triglyceride substrates. northern blot analyses revealed that expression of lip1 was activated i ... | 2005 | 16339936 |
| internal transcribed spacer sequencing versus biochemical profiling for identification of medically important yeasts. | in this study, we established an in-house database of yeast internal transcribed spacer (its) sequences. this database includes medically important as well as colonizing yeasts that frequently occur in the diagnostic laboratory. in a prospective study, we compared molecular identification with phenotypic identification by using the id32c system (biomérieux) for yeast strains that could not be identified by a combination of chromagar candida and morphology on rice agar. in total, 113 yeast strain ... | 2006 | 16390952 |
| microscopic analysis of ester hydrolysis reaction catalyzed by candida rugosa lipase. | the relationship between the kinetics of the lipase-catalyzed oil hydrolysis and the surface area distribution of oil droplets was investigated using ethyl decanoate and gum arabic (ga) as a model oil and an emulsifier, respectively. along an ethyl decanoate concentration gradient between 2 and 8 mm, the initial hydrolysis rate increased at 0.25% (w/v) ga but did not change at 1.0% (w/v) ga. at 0.25% ga, the surface area of droplets was narrowly distributed regardless of the ethyl decanoate conc ... | 2006 | 16406517 |
| codon optimization of candida rugosa lip1 gene for improving expression in pichia pastoris and biochemical characterization of the purified recombinant lip1 lipase. | an important industrial enzyme, candida rugosa lipase (crl) possesses several different isoforms encoded by the lip gene family (lip1-lip7), in which the recombinant lip1 is the major form of the crl multigene family. previously, 19 of the nonuniversal serine codons (ctg) of the lip1 gene hav been successfully converted into universal serine codons (tct) by overlap extension pcr-based multiple-site-directed mutagenesis to express an active recombinant lip1 in the yeast pichia pastoris. to improv ... | 2006 | 16448188 |
| application of sscp-pcr fingerprinting to profile the yeast community in raw milk salers cheeses. | bacteria and yeasts are important sensory factors of raw-milk cheeses as they contribute to the sensory richness and diversity of these products. the diversity and succession of yeast populations in three traditional registered designation of origin (r.d.o.) salers cheeses have been determined by using phenotypic diagnoses and single-strand conformation polymorphism (sscp) analysis. isolates were identified by phenotypic tests and the sequencing of the d1-d2 domains of the 26s rrna gene. ninety- ... | 2006 | 16464699 |
| pre-treatment of high oil and grease pet food industrial wastewaters using immobilized lipase hydrolyzation. | wastewaters generating from pet food industries contain high concentration of oil and grease (o&g), which is difficult to treat through conventional biological treatment systems. in this study, the hydrolysis of o&g originating from pet food industrial wastewater was evaluated. candida rugosa lipase was immobilized in calcium alginate beads and applied in the hydrolysis experiment. results showed that approximately 50% of the o&g was hydrolyzed due to the enzyme activity. a significant increment ... | 2006 | 16504384 |
| efficient hydrolysis of tuna oil by a surfactant-coated lipase in a two-phase system. | a surfactant-coated lipase (scl) prepared by mixing candida rugosa lipase with emulsifier in ethanol was used to hydrolyze tuna oil in a two-phase aqueous-organic system. both enzyme (scl) and substrate (tuna oil) were soluble in the organic phase, and the hydrolysis could occur with water molecules from the aqueous phase. this hydrolysis could promptly proceed compared to that catalyzed by native lipases which only occurred at the interface between the two phases. michaelis-menten kinetics in t ... | 2006 | 16506843 |
| lipase-catalyzed esterification of 2-monoricinolein for 1,2 (2,3)-diricinolein synthesis. | the purpose of this investigation was to develop conditions for producing 2-monoricinoleoyl dag. we used lipase-catalyzed hydrolysis of triricinolein to obtain 2-monoricinolein and thereafter synthesized 1,2(2,3)-diricinolein through esterification of 2-monoricinolein, using ricinoleic acid as the acyl donor. five different 1,3-specific immobilized lipases were tested for the initial methanolysis reaction: candida antarctica type b, rhizomucor miehei, rhizopus oryzae (rol), thermomyces lanuginos ... | 2006 | 16555475 |
| nanofibrous poly(acrylonitrile-co-maleic acid) membranes functionalized with gelatin and chitosan for lipase immobilization. | nanofibrous membranes with an average diameter of 100 and 180 nm were fabricated from poly(acrylonitrile-co-maleic acid) (pancma) by the electrospinning process. these nanofibrous membranes contain reactive groups which can be used to covalently immobilize biomacromolecules. two natural macromolecules, chitosan and gelatin, were tethered on these nanofibrous membranes to fabricate dual-layer biomimetic supports for enzyme immobilization in the presence of 1-ethyl-3-(dimethyl-aminopropyl) carbodi ... | 2006 | 16584770 |
| synthesis of structured lipids containing medium-chain and omega-3 fatty acids. | the ability of different lipases to incorporate omega3 fatty acids, namely, eicosapentaenoic acid (epa, c20:5n-3), docosapentaenoic acid (dpa, c22:5n-3), and docosahexaenoic acid (dha, c22:6n-3), into a high-laurate canola oil, known as laurical 35, was studied. lipases from mucor miehei (lipozyme-im), pseudomonas sp. (ps-30), and candida rugosa (ay-30) catalyzed optimum incorporation of epa, dpa, and dha into laurical 35, respectively. other lipases used were candida anatrctica (novozyme-435) a ... | 2006 | 16756372 |
| candida rugosa lipase lip1-catalyzed transesterification to produce human milk fat substitute. | structured lipids (sls) containing palmitic and oleic acids were synthesized by transesterification of tripalmitin with either oleic acid or methyl oleate as acyl donor. this sl with palmitic acid at the sn-2 position and oleic acid at sn-1,3 positions is similar in structure to human milk fat triacylglycerol. lip1, an isoform of candida rugosa lipase (crl), was used as biocatalyst. the effects of reaction temperature, substrate molar ratio, and time on incorporation of oleic acid were investiga ... | 2006 | 16819932 |
| optimized growth kinetics of pichia pastoris and recombinant candida rugosa lip1 production by rsm. | a predictive model for pichia pastoris expression of highly active recombinant candida rugosa lip1 was developed by combining the gompertz function and response surface methodology (rsm) to evaluate the effect of yeast extract concentration, glucose concentration, temperature, and ph on specific responses. each of the responses (maximum population densities, specific growth rate (mumax), protein concentration, and minimum lag phase duration) was determined using the modified gompertz function. r ... | 2006 | 16825788 |
| atomic force microscope studies on the interactions of candida rugosa lipase and supported lipidic bilayers. | using the langmuir-blodgett technique we prepared substrate supported well-defined lipid/phospholipid (1-mono-palmitoyl-rac-glycerol (mpg)/l,2-dipalmitoyl-sn-glycerol-3-phosphocholine (dppc)) bilayers in which the mpg lipid leaflet was exposed to the aqueous phase. hydrolysis of mpg performed by candida rugosa lipase (crl) on the upper mpg layer of these supported bilayers on mica was imaged by real time atomic force microscope (afm) using a liquid cell, so that the area increase of the initial ... | 2006 | 16829060 |
| studies of reaction parameters on synthesis of citronellyl laurate ester via immobilized candida rugosa lipase in organic media. | immobilized candida rugosa lipase was used for the synthesis of citronellyl laurate from citronellol and lauric acid. screening of different types of support (amberlite mb-1 and celite) for immobilization of lipase and solvent (n-hexane, n-heptane, and iso-octane) and optimization of reaction conditions, such as catalyst loading, effect of substrates molar ratio and temperature, have been studied. the maximum enzyme activity was obtained at 310 k. the immobilized c. rugosa lipase onto amberlite ... | 2006 | 16868763 |
| efficient production of active recombinant candida rugosa lip3 lipase in pichia pastoris and biochemical characterization of the purified enzyme. | candida rugosa lipase (crl), an important industrial enzyme, possesses several different isoforms encoded by the high-identity lip gene family (lip1 to lip7). in this study, an additional n-terminal peptide in front of the lip3 gene was removed by pcr, and the 18 nonuniversal serine codons (ctg) of the lip3 gene were converted into universal serine codons (tct) by means of an overlap extension pcr-based multiple-site-directed mutagenesis to express an active recombinant lip3 in the yeast pichia ... | 2006 | 16881684 |
| glutaraldehyde cross-linking of lipases adsorbed on aminated supports in the presence of detergents leads to improved performance. | lipases from candida rugosa (crl) and lipase isoforms a and b from candida antarctica (cal-a and cal-b) were adsorbed on aminated supports in the presence of detergents to have individual lipase molecules. then, one fraction was washed to eliminate the detergent, and both preparations were treated with glutaraldehyde. the presence of detergent during the cross-linking of the lipases to the support permitted an increase in the recovered activity (in some instances, even by a 10-fold factor). this ... | 2006 | 16961324 |
| candida rugosa, an emerging fungal pathogen with resistance to azoles: geographic and temporal trends from the artemis disk antifungal surveillance program. | candida rugosa is a fungus that appears to be emerging as a cause of infection in some geographic regions. we utilized the extensive database of the artemis disk antifungal surveillance program to describe the geographic and temporal trends in the isolation of c. rugosa from clinical specimens and the in vitro susceptibilities of 452 isolates to fluconazole and voriconazole. c. rugosa accounted for 0.4% of 134,715 isolates of candida, and the frequency of isolation increased from 0.03% to 0.4% o ... | 2006 | 17021085 |
| increased enantioselectivity and remarkable acceleration of lipase-catalyzed transesterification by using an imidazolium peg-alkyl sulfate ionic liquid. | several types of imidazolium salt ionic liquids were prepared derived from poly(oxyethylene)alkyl sulfate and used as an additive or coating material for lipase-catalyzed transesterification in an organic solvent. a remarkably increased enantioselectivity was obtained when the salt was added at 3-10 mol % versus substrate in the burkholderia cepacia lipase (lipase ps-c)-catalyzed transesterification of 1-phenylethanol by using vinyl acetate in diisopropyl ether or a hexane solvent system. in par ... | 2006 | 17029309 |
| acidolysis and glyceride synthesis reactions using fatty acids with two pseudomonas lipases having different substrate specificities. | enzymatic acidolysis and glyceride synthesis using polyunsaturated fatty acids (pufas) with lipases from pseudomonas fluorescens hu380 (hu-lipase), p. fluorescens ak102 (ak-lipase), and candida rugosa (cr-lipase) were studied. the acidolysis of triolein with eicosapentaenoic acid (epa) or docosahexaenoic acid (dha) in n-hexane was evaluated with lipases immobilized on celite 545. hu-lipase showed the highest incorporation rate at a low temperature (10 degrees c) with either epa or dha as the acy ... | 2006 | 17046530 |
| investigating ph and cu (ii) effects on lipase activity and enantioselectivity via kinetic and spectroscopic methods. | for candida rugosa lipase (crl) catalyzed hydrolysis of racemic 1-phenethyl acetate, both the weakly acidic ph (ph 6.0) and the addition of 1 mm copper (ii) ion enhanced the enzyme activity and enantioselectivity (e value) about twofold, as compared with that under neutral ph and noadditive conditions. the decrease of activation free energy (deltag) and increase of k(cat)(r)/k(cat)(s) at weakly acidic ph and/or in the presence of copper (ii) characterized the kinetic behavior of crl. on the othe ... | 2006 | 17068757 |
| a water activity control system for enzymatic reactions in organic media. | a water activity control system for enzymatic synthesis in organic media, for litre-scale reactors has been constructed. water activity, a(w), is a key factor when using enzymes in non-conventional media and the optimum value varies for different enzymes. the control system consists of a water activity sensor in the headspace of a jacketed glass reactor (equipped with narrow steel tubes to introduce air), gas-washing bottles containing blue silica gel (a(w)=0) and water (a(w)=1), a pc to monitor ... | 2007 | 17096388 |
| kinetic resolution of (+/-)-1-phenylethanol in [bmim][pf6] using high activity preparations of lipases. | lipases from two different sources candida rugosa (crl) and burkholderia cepacia (bcl) were formulated as enzyme precipitated and rinsed with organic solvents, organic solvent rinsed enzyme preparation, cross-linked enzyme aggregates (cleas) and protein coated micro-crystals (pcmcs). these various enzyme formulates were evaluated for the kinetic resolution of (+/-)-1-phenylethanol in ionic liquid [bmim][pf(6)] by transesterification with vinyl acetate. of all the enzyme forms evaluated eprp and ... | 2007 | 17157018 |
| antifungal susceptibility of 1000 candida bloodstream isolates to 5 antifungal drugs: results of a multicenter study conducted in são paulo, brazil, 1995-2003. | we evaluated all candida sp. bloodstream isolates obtained from patients admitted to 4 tertiary care hospitals between 1995 and 2003 in the city of são paulo, brazil. susceptibility to amphotericin b, 5-fluorocytosine, fluconazole (fcz), itraconazole (itz), and voriconazole (vcz) was determined using the clinical laboratory standards institute broth microdilution method. we tested a total of 1000 strains, including 400 strains of candida albicans (40%), 243 of candida tropicalis (24.3%), 238 of ... | 2007 | 17240110 |
| hofmeister effects in enzymatic activity: weak and strong electrolyte influences on the activity of candida rugosa lipase. | the effects of weak and strong electrolytes on the enzymatic activity of candida rugosa lipase are explored. weak electrolytes, used as buffers, set the ph, while strong electrolytes regulate the ionic strength. the interplay between ph and ionic strength has been assumed to be the determinant of enzymatic activity. in experiments that probe activities by varying these parameters, there has been little attention focused on the role of specific electrolyte effects. here we show that both buffers ... | 2007 | 17266269 |
| characterization of lipase in reversed micelles formulated with cibacron blue f-3ga modified span 85. | sorbitan trioleate (span 85) modified by cibacron blue f-3ga (cb) was prepared and used as an affinity surfactant to formulate a reversed micellar system for candida rugosa lipase (crl) solubilization. the system was characterized and evaluated by employing crl-catalyzed hydrolysis of olive oil as a model reaction. the micellar hydrodynamic radius results reflected, to some extent, the redistribution of surfactant and water after enzyme addition, and the correlation between surfactant formulatio ... | 2007 | 17269677 |
| impact of aluminum on the oxidation of lipids and enzymatic lipolysis in monomolecular films at the air/water interface. | there is evidence that serious pathologies are associated with aluminum (al). in the present work, the influence of al on enzymatic lipolysis was studied with the aim to get more insight into the possible link between the al-induced membrane modification and the cytotoxicity of the trivalent cation (aliii). lipid monolayers were used as model membranes. the monomolecular film technique allowed monitoring the al-dependent modifications of the lipid monolayer properties and enzyme kinetics. two en ... | 2007 | 17279785 |
| acidolysis of tristearin with selected long-chain fatty acids. | five lipases, namely, candida antarctica (novozyme-435), mucor miehei (lipozyme-im), pseudomonas sp. (ps-30), aspergillus niger (ap-12), and candida rugosa (ay-30), were screened for their effect on catalyzing the acidolysis of tristearin with selected long-chain fatty acids. among the lipases tested c. antarctica lipase catalyzed the highest incorporation of oleic acid (oa, 58.2%), gamma-linolenic acid (gla, 55.9%), eicosapentaenoic acid (epa, 81.6%), and docosahexaenoic acid (dha, 47.7%) into ... | 2007 | 17288439 |
| an approach to address candida rugosa lipase regioselectivity in the acylation reactions of trytilated glucosides. | candida rugosa lipase crude preparations (crl) catalyse the regioselective acylation of methyl 6-o-trytil beta-d-glucopyranoside in organic solvents, using vinyl acetate as acyl donor. the ratio of the two products formed, namely methyl 2-o acetyl 6-o-trytil beta-d-glucopyranoside and methyl 3-o acetyl 6-o-trytil beta-d-glucopyranoside was found to be markedly affected by the nature of the reaction medium. in hydrophobic solvents values up to 80% of the monoacetylated product in position c-3 wer ... | 2007 | 17321623 |
| inhibition of rhizomucor miehei and candida rugosa lipases by d-glucose in esterification between l-alanine and d-glucose. | a detailed kinetic study of the esterification of d-glucose with l-alanine catalyzed by lipases from rhizomucor miehei (rml) and candida rugosa (crl) showed that both lipases follow the ping-pong bi-bi mechanism, in which l-alanine and d-glucose bind in subsequent steps releasing water and l-alanyl-d-glucose, with competitive substrate inhibition by d-glucose at higher concentrations leading to the formation of dead-end lipase.d-glucose complexes. an attempt to obtain the best fit of this kineti ... | 2007 | 17368393 |
| an enzyme derivatized polydimethylsiloxane (pdms) membrane for use in membrane introduction mass spectrometry (mims). | membrane introduction mass spectrometry (mims) provides direct measurement of volatile and semivolatile analytes in condensed and gas-phase samples without sample preparation steps. although mims has numerous advantages that include direct, on-line, real-time analysis with low detection limits, current applications of mims are predominantly limited to volatile and semivolatile analytes that permeate hydrophobic membranes (e.g., polydimethylsiloxane; pdms). we report the first enzyme modified pdm ... | 2007 | 17395478 |
| candida rugosa lipase-catalyzed polyurethane degradation in aqueous medium. | candida rugosa lipase (ec 3.1.1.3) was used to degrade commercially-available solid poly(ester)urethane (impranil) in an aqueous medium under different temperature, ph, enzyme and substrate concentrations. a mathematical model was developed and applied to represent the degradation kinetics of the solid polyurethane. reaction optima were found to be ph 7 and 35 degrees c. diethylene glycol, a degradation byproduct, generation rate was measured to be 0.12 mg/l min and the activation energy was cal ... | 2007 | 17450322 |
| immobilization of candida rugosa lipase on magnetized dacron: kinetic study. | candida rugosa lipase has been covalently immobilized on ferromagnetic azide polyethyleneterepthalate (dacron) with specific activity retention of 16% for 4-nitrophenyl palmitate and 24% for hydrolysis of triolein in hexane. the immobilized enzyme was more thermal stable than the soluble one, retaining 78.8% of the activity after 1 h at 60 degrees c. also, this immobilized derivative was stable at the storage at 4 degrees c. it has been used 5 cycles for pnpp hydrolysis without loss of activity. ... | 2007 | 17453706 |
| prospective observational study of candidemia in são paulo, brazil: incidence rate, epidemiology, and predictors of mortality. | studies conducted in tertiary care hospitals of different european countries and the united states have shown incidence rates of candidemia ranging from 0.17 to 0.76 and 0.28 to 0.96 per 1,000 admissions, respectively. so far, only 1 study has evaluated the incidence rates of candidemia in tertiary care hospitals in latin american countries. | 2007 | 17464917 |
| a method for lipase co-precipitation in a biodegradable protein matrix. | this article presents a novel method for immobilization of active ingredients. the method is based on co(2) aided active ingredient co-precipitation with glycinin, a biodegradable protein matrix from edible soybean protein. glycinin precipitates abundantly under isoelectric conditions and serves as the matrix within which the active substance is trapped during the precipitation process. the enzyme lipase from candida rugosa was successfully co-precipitated into the protein pellet to prove the pr ... | 2007 | 17514752 |
| altering the substrate specificity of candida rugosa lip4 by engineering the substrate-binding sites. | candida rugosa (formerly candida cylindracea) lipase (crl) is an important industrial enzyme that is widely used in biotechnological applications such as the production of fatty acids and the synthesis of various esters. crl comprises at least seven isozymes (lip1-lip7), which share a similar amino acid sequence but with different specificities for substrates. previously, lip4 was reported to have higher esterase activity toward long acyl-chain ester and lower lipase activity toward triglyceride ... | 2007 | 17536826 |
| peptidase profiles from non-albicans candida spp. isolated from the blood of a patient with chronic myeloid leukemia and another with sickle cell disease. | candida lipolytica and candida rugosa were isolated from blood samples from a patient with chronic myeloid leukemia (31 years old) and a patient with sickle cell disease (1-year-old), respectively. isolates were grown for 48 h at 37 degrees c in either sabouraud or tryptone soy broth (tsb). peptidases were tested for using substrate sodium dodecyl sulfate-polyacrylamide gels with gelatin, casein, bovine serum albumin (bsa) or hemoglobin. enzymography analyses were made on the following substrate ... | 2007 | 17559410 |
| immobilization of lipase by ultrafiltration and cross-linking onto the polysulfone membrane surface. | in this study, a biphasic enzymatic membrane reactor was made by immobilizing candida rugosa lipase onto the dense surface of polysulfone ultrafiltration membrane by filtration and then cross-linking with glutaraldehyde solution. the reactor was further applied for the hydrolysis of olive oil, the performance of which was evaluated in respect of apparent reaction rate based on the amount of fatty acids extracted into the aqueous phase per minute and per membrane surface. it was found that the ul ... | 2008 | 17591438 |
| adsorption and activity of lipase from candida rugosa on the chitosan-modified poly(acrylonitrile-co-maleic acid) membrane surface. | efforts have recently been made to improve the biocompatibility of support surface for enzyme immobilization, which could create a specific microenvironment for the enzymes and thus benefit the enzyme activity. in this work, one natural macromolecule, chitosan, was tethered on the surface of poly(acrylonitrile-co-maleic acid) (pancma) membrane to prepare a dual-layer biomimetic support for enzyme immobilization. lipase from candida rugosa was immobilized on this dual-layer biomimetic support by ... | 2007 | 17616362 |
| a parametric study on biphasic medium conditions for the enantioselective production of naproxen by candida rugosa lipase. | a parametric study to increase the enantioselectivity of candida rugosa lipase (crl) toward s-naproxen production by the hydrolysis of racemic naproxen methyl ester in an aqueous-organic biphasic batch system was carried out. effects of organic solvent type, aqueous phase/organic solvent volume ratio, agitation rate, concentrations of the substrate and the enzyme, ph of the aqueous phase, and temperature on the enantiomeric excess for the product (eep), on the enantiomeric ratio (e) and on the c ... | 2007 | 17625263 |
| synthesis of isoamyl laurate and isoamyl stearate in supercritical carbon dioxide. | the synthesis of isoamyl laurate and isoamyl stearate was studied in supercritical carbon dioxide with three lipases, novozym 435, lipolase 100t, and candida rugosa. the maximum conversion of 37% and 53%, respectively for isoamyl laurate and isoamyl stearate was obtained when novozym 435 was used. the effect of various parameters such as molar ratio of alcohol to acid, presence of water, time and temperature was investigated. an optimum temperature of 40-45 degrees c was observed for all reactio ... | 2007 | 17625272 |
| optimization of medium composition for lipase production by candida rugosa ncim 3462 using response surface methodology. | a sequential optimization approach using statistical design of experiments was employed to enhance the lipase production by candida rugosa in submerged batch fermentation. twelve medium components were evaluated initially using the plackett-burman 2-level factorial design. the significant variables affecting lipase production were found to be glucose, olive oil, peptone, (nh4)2so4, and fecl3.6h2o. various vegetable oils were tested in the second step, and among them, groundnut oil was found to b ... | 2007 | 17668023 |
| use of insoluble yeast beta-glucan as a support for immobilization of candida rugosa lipase. | in the present study, insoluble yeast beta-glucan (iyg) has been explored as a support matrix for enzyme immobilization. iyg contains mainly beta-(1-3) linkages along with some intra- or inter-molecular branches of beta-(1-6) linkages with large number of free hydroxyl groups. epichlorohydrin was used to convert these free hydroxyl groups into activated epoxy groups that are capable of forming covalent linkages with various groups of enzyme molecule. the epoxy-activated iyg was evaluated for imm ... | 2008 | 17681766 |
| studies of optimum conditions for covalent immobilization of candida rugosa lipase on poly(gamma-glutamic acid) by rsm. | poly(gamma-glutamic acid) (gamma-pga) is a material of polymer. immobilization of candida rugosa lipase (lipase ay-30) by covalent binding on gamma-pga led to a markedly improved performance of the enzyme. response surface methodology (rsm) and 3-level-3-factor fractional factorial design were employed to evaluate the effects of immobilization parameters, such as immobilization time (2-6h), immobilization temperature (0-26 degrees c), and enzyme/support ratio (0.1-0.5, w/w). based on the analysi ... | 2008 | 17706421 |
| activation of candida rugosa lipase at alkane-aqueous interfaces: a molecular dynamics study. | the effect of solvent hydrophobicity on activation of candida rugosa lipase (crl) was investigated by performing molecular dynamics simulations for four nano seconds (ns). the closed/inactive conformer of crl (pdb code 1trh) was solvated in three alkane-aqueous environments. the alkanes aggregated in a predominantly aqueous environment and by 1 ns a stable spherical alkane-aqueous interface had formed. this led to the interfacial activation of crl. on analyzing the simulated conformers with the ... | 2007 | 17765226 |
| immobilization of candida rugosa lipase on poly(allyl glycidyl ether-co-ethylene glycol dimethacrylate) macroporous polymer particles. | macroporous polymer particles containing surface epoxy groups were synthesized for immobilization of candida rugosa lipase (crl). the effect of incorporation of two different sets of monomers [allyl glycidyl ether (age) and glycidyl methacrylate (gma)] and the effect of crosslinking density on immobilization of lipase were studied. age-co-egdm polymers gave higher binding and expression of lipase than gma-co-egdm polymers. optimization of immobilization parameters was done with respect to immobi ... | 2008 | 17766105 |