Publications

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
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
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
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
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
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
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
reactivity of pure candida rugosa lipase isoenzymes (lip1, lip2, and lip3) in aqueous and organic media. influence of the isoenzymatic profile on the lipase performance in organic media.	three pure isoenzymes from candida rugosa lipase (crl: lip1, lip2, and lip3) were compared in terms of their stability and reactivity in both aqueous and organic media. the combined effect of temperature and ph on their stability was studied applying a factorial design. the analysis of the response surfaces indicated that lip1 and lip3 have a similar stability, lower than that of lip2. in aqueous media, lip3 was the most active enzyme on the hydrolysis of p-nitrophenyl esters, whereas lip1 showe ...	2004	14763825
studies on a novel carbon source and cosolvent for lipase production by candida rugosa.	oleic acid esters were shown to be the best carbon source for both cell growth and lipase production by candida rugosa. use of a cosolvent, dodecane, in fermentations improved the solubility of solid substrates and increased oxygen solubility. this resulted in the highest lipase activity in batch fermentation with glycerol trioleate and dodecane. lipase activity reached 77.1 units ml(-1).	2004	15069604
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
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
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
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
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
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
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
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
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
hydrolysis of rice bran oil using an immobilized lipase from candida rugosa in isooctane.	the kinetics of enzymatic hydrolysis of rice bran oil in isooctane by immobilized candida rugosa lipase in a batch reactor showed competitive inhibition by isooctane with a dissociation constant, k1, of 0.92 m. continuous hydrolysis of rice bran oil was performed in recycling, packed bed reactor with 4352 u of immobilized lipase; the optimum recycle ratio was 9 and the operational half-life was 360 h without isooctane but 288 h with 25% (v/v) isooctane in rice bran oil.	2004	15168855
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
immobilization of candida rugosa lipase on chitosan with activation of the hydroxyl groups.	a method for immobilization of candida rugosa lipase to two types of chitosan beads by activating the hydroxyl groups of chitosan using carbodiimide coupling agent has been successfully developed. the ability of carbodiimide to activate the hydroxyl groups of chitosan was confirmed using the electron spectroscopy for chemical analysis (esca) technique. the properties of lipase immobilized using dry and wet chitosan beads were also investigated and compared. immobilization enhanced the enzyme sta ...	2004	14585707
characterisation of steryl esterase activities in commercial lipase preparations.	triglycerides, steryl esters, resin acids, free fatty acids and sterols are lipophilic extractives of wood (commonly referred to as pitch or wood resin) and have a negative impact on paper machine runnability and quality of paper. thus, enzymes capable of modifying these compounds would be potential tools for reducing pitch problems during paper manufacture. in this work, 19 commercial lipase preparations were tested for their ability to degrade steryl esters, which may play a significant role i ...	2004	14741769
effects of preparative parameters on the properties of chitosan hydrogel beads containing candida rugosa lipase.	the influences of the ph, tripolyphosphate (tpp) concentration, and ionic strength of the gelling medium on the entrapment efficiency, release, and activity of lipase in chitosan hydrogel beads were studied. a solution of candida rugosa lipase was prepared in a 1.5% w/v chitosan and 1% (v/v) acetic acid medium, and dropped into a tpp solution. release of lipase in ph 7.2 tris buffer was monitored over 36 h using the micro bca protein assay. the activity of the entrapped enzyme was assayed using ...	2004	14751751
immobilization of lipase on chitin and its use in nonconventional biocatalysis.	chitin was functionalized with hexamethylenediamine followed by glutaraldehyde activation, and its capacity to bind candida rugosa lipase was investigated. the loading of 250 units g(-1) support showed to be effective, resulting in a uniform enzyme fixation with high catalytic activity. both free and immobilized lipases were characterized by determining the activity profile as a function of ph, temperature, and thermal stability. for the immobilized lipase, the influence of the reaction temperat ...	2004	14715003
enantiodivergent preparation of optically active oxindoles having a stereogenic quaternary carbon center at the c3 position via the lipase-catalyzed desymmetrization protocol: effective use of 2-furoates for either enzymatic esterification or hydrolysis.	both enantiomers of oxindoles 2a-h, having a stereogenic quaternary carbon center at the c3 position and a different n-protective group, were readily prepared by the lipase-catalyzed desymmetrization protocol. thus, the transesterification of the prochiral diols 3a-h with 1-ethoxyvinyl 2-furoate 5 was catalyzed by candida rugosa lipase to give (r)-(+)-2a-h (68-99% ee), in which the use of a mixed solvent, (i)pr(2)o (diisopropyl ether)-thf, was crucial. the same lipase also effected the enantiose ...	2004	15049648
studies on immobilized lipase in hydrophobic sol-gel.	the hydrolysis of tetraethoxysilane using the sol-gel process was used to produce silica matrices, and these were tested for the immobilization of lipase from candida rugosa by three methods: physical adsorption, covalent binding, and gel entrapment in the presence and absence of polyethylene glycol (peg-1450). the silica matrices and their derivatives were characterized regarding particle size distribution, specific surface area, pore size distribution (brunauer, emmett, and teller [b.e.t.] met ...	2004	15054215
a convenient preparation of 1,2,3-tri-o-acetyl-beta-d-ribofuranose by enzymatic regioselective 5-o-deacetylation of the peracetylated ribofuranose.	the lipase from candida rugosa (sigma) was used to catalyze the regioselective deacetylation at the 5-position of 1,2,3,5-tetra-o-acetyl-beta-d-ribofuranose on a preparative scale. enzymatic deacetylation provides a convenient one-step preparation of 1,2,3-tri-o-acetyl-beta-d-ribofuranose.	2004	15063214
activation and inhibition of candida rugosa and bacillus-related lipases by saturated fatty acids, evaluated by a new colorimetric microassay.	research on lipase inhibitors could help in the therapy of diseases caused by lipase-producing microorganisms and in the design of novel lipase substrate specificities for biotechnology. here we report a fast and sensitive colorimetric microassay that is low-cost and suitable for high-throughput experiments for the evaluation of lipase activity and inhibition. comparison of candida rugosa activity and inhibition with previous hplc results validated the method, and revealed the importance of the ...	2004	15182938
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
preparation of gemini-type amphiphiles bearing cyclitol head groups and their application as high-performance modifiers for lipases.	five gemini-type amphiphiles bearing cyclitol head groups, which have abundance of axial hydroxy groups, are newly synthesized. the syntheses are based on a common mixed anhydride method utilizing n,n'-[iminobis(trimethylene)]bisquinamide, prepared from iminobispropylamine and quino-1,5-lactone, and dialkyl n-(3-carboxypropanoyl)-l-glutamates as polar and hydrophobic components, respectively. candida rugosa lipase (crl) and pseudomonas cepacia lipase (pcl) are co-lyophilized with these synthesiz ...	2004	15013386
utilizing hydrolases of opposite enantiopreference for the preparation of both enantiomers of (1r,7ar)-(-)- and (1s,7as)-(+)-3,6,7,7a-tetrahydro-1-hydroxy-7a-methyl-1h-inden-5(2h)-one.	four racemic esters of (1r,7ar)-3,6,7,7a-tetrahydro-1-hydroxy-7a-methyl-1h-inden-5(2h)-one were prepared and subjected to hydrolysis with two types of hydrolases, including alcalase and three lipases. alcalase and lipase showed opposite enantiopreference on these esters. based on this result, we developed a gram-scale procedure using butanoate as the substrate, which was treated consecutively with alcalase and lipase from candida rugosa (crl), to give both enantiomers of the title compound in ...	2004	15034910
activity and enantioselectivity of wildtype and lid mutated candida rugosa lipase isoform 1 in organic solvents.	the activity and enantioselectivity of lipase 1 from candida rugosa and of a chimera enzyme obtained by replacing the lid of isoform 1 with the lid of isoform 3 were compared in organic solvents. the alcoholysis of chloro ethyl 2-hydroxy hexanoate with methanol and of vinyl acetate with 6-methyl-5-hepten-2-ol were used as model reactions in different reaction conditions. the chimera enzyme was less active and enantioselective than the wildtype in all the conditions tested. a rationale for such d ...	2004	15052644
characteristics of immobilized lipase on hydrophobic superparamagnetic microspheres to catalyze esterification.	a novel immobilized lipase (from candida rugosa) on hydrophobic and superparamagnetic microspheres was prepared and used as a biocatalyst to catalyze esterification reactions in diverse solvents and reaction systems. the results showed that the immobilized lipase had over 2-fold higher activities in higher log p value solvents. an exponential increase of lipase activity against log p of two miscible solvent mixtures was observed for the first time. both free and immobilized lipase achieved its m ...	2004	15058995
integration of purification with immobilization of candida rugosa lipase for kinetic resolution of racemic ketoprofen.	the two processes for the partial purification and for the immobilization of a crude lipase preparation (candida rugosa lipase of) have been successfully integrated into one by simple adsorption of the enzyme onto a cation ion exchanger resin (sp-sephadex c-50) at ph 3.5. due to selective removal of the unfavorable lipase isoenzyme (l1), the enzyme components (mainly l2 and l3) that are tightly fixed on the resin displayed a significantly improved enantioselectivity (e value: 50 versus 13 with a ...	2004	15121339
evaluation of the catalytic activity of lipases immobilized on chrysotile for esterification.	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 25 c in hexane as solvent. the best results were obtained with mucor javani ...	2003	12894300
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
monitoring the transport of recombinant candida rugosa lipase by a green fluorescent protein-lipase fusion.	in a batch cultivation of pichia pastoris expressing candida rugosa lipase 1 (crl1), secretion of 200 microg lipase ml(-1) of culture was achieved in sorbitol-based medium. however, a large amount of recombinant protein was retained intracellularly throughout the fermentation, pointing to the transport step as a major bottleneck. therefore a translational fusion with the green fluorescent protein (gfp) was constructed that was expressed and transported similarly to the native lipase and retained ...	2003	14719831
stereochemistry of a diastereoisomeric amphiphile and the species of the lipase influence enzyme activity in the transesterification catalyzed by a lipase-co-lyophilizate with the amphiphile in organic media.	modified candida rugosa and pseudomonas cepacia lipase (crl and pcl) were co-lyophilized with two pairs of synthetic diastereoisomeric amphiphiles, d- and l-2-(3-[bis-[3-(2,3,4,5,6-pentahydroxy-hexanoylamino)-propyl]-carbamoyl]-propionylamino)-pentanedioic acid didodecyl ester (d- and l-big2c12ca); d- and l-2-(2,3,4,5,6-pentahydroxy-hexanoylamino)-pentanedioic acid didodecyl ester (d- and l-2c12ge). enzyme activities of the modified lipase in the transesterification in organic solvent were evalu ...	2003	14677713
immobilization of lipases and assay in continuous fixed bed reactor.	lipases are versatile enzymes regarding the range of reactions they catalyse and substrates on which they act. they are as well important as catalyst in organic synthesis. their immobilization on appropriate supports confer them greater stability besides the possibility of operating in continuous reactors. in order to explore these abilities, the reactions involving hydrolysis of p-nitrophenyl acetate (pnpa) and transesterification of pnpa with n-butanol were chosen. lipases from two different s ...	2003	14683514
strategic selection of hyperthermophilic esterases for resolution of 2-arylpropionic esters.	homologues to carboxylesterase np and candida rugosa lipase, used for the chiral separation of racemic mixtures of 2-arylpropionic methyl esters, were identified by blast searches of available genome sequences for hyperthermophilic microorganisms. two potential candidates were identified: a putative lysophospholipase from pyrococcus furiosus (pfu-lpl) and a carboxylesterase from sulfolobus solfataricus p1 (sso-est1). although both enzymes showed hydrolytic preference toward the (s) methyl ester, ...	2003	14524700
lipases for biocatalysis: development of a chromatographic bioreactor.	the development of a new chromatographic reactor based on immobilized candida rugosa lipase (crl) is described. the chromatographic system has been used to evaluate the rate differences by which the product enantiomers of esterolytic reactions catalyzed by immobilized crl are obtained. the method has been applied to a series of racemic 2-aryloxyalkanoic acids and isosteric analogous methyl esters and to some non-steroidal antiinflammatory drugs 2-arylpropanoic acids methyl esters in order to stu ...	2003	12899962
sequence of the lid affects activity and specificity of candida rugosa lipase isoenzymes.	the fungus candida rugosa produces multiple lipase isoenzymes (crls) with distinct differences in substrate specificity, in particular with regard to selectivity toward the fatty acyl chain length. moreover, isoform crl3 displays high activity towards cholesterol esters. lipase isoenzymes share over 80% sequence identity but diverge in the sequence of the lid, a mobile loop that modulates access to the active site. in the active enzyme conformation, the open lid participates in the substrate-bin ...	2003	14500889
outbreak of candida rugosa candidemia: an emerging pathogen that may be refractory to amphotericin b therapy.	candida rugosa has been rarely reported as a human pathogen. we retrospectively evaluated a cluster of candida rugosa candidemia cases occurring in six hospitalized patients from a tertiary care teaching hospital in são paulo, brazil. genetic relatedness among the six c. rugosa outbreak isolates was characterized by rapd assay using 3 different 10-mer primers and by pulsed field gel electrophoresis. the source of the outbreak was not identified. all patients had been subjected to invasive medica ...	2003	12944016
structural insights into the lipase/esterase behavior in the candida rugosa lipases family: crystal structure of the lipase 2 isoenzyme at 1.97a resolution.	the yeast candida rugosa produces several closely related extracellular lipases that differ in their substrate specificity. here, we report the crystal structure of the isoenzyme lipase 2 at 1.97a resolution in its closed conformation. lipase 2 shows a 79.4% amino acid sequence identity with lipase 1 and 82.2% with lipase 3, which makes it relevant to compare these three isoenzymes. despite this high level of sequence identity, structural comparisons reveal several amino acid changes affecting t ...	2003	14499609
detection of simulated candidemia by the bactec 9240 system with plus aerobic/f and anaerobic/f blood culture bottles.	we studied the ability of the bactec 9240 automated blood culture system to detect simulated candidemia, including both candida albicans and non-albicans candida species. simulated blood cultures were produced using 50 candida isolates and bactec plus aerobic/f and anaerobic/f blood culture bottles. ten milliliters of blood and a suspension of each isolate containing 1,000 cfu were introduced into each bottle and then incubated at 35 degrees c in the bactec 9240 system. the system detected growt ...	2003	14532209
a transformation system for the nonuniversal cug(ser) codon usage species candida rugosa.	since candida rugosa utilizes a nonuniversal serine codon cug rather than leucine, no vectors have been constructed to transform this organism. moreover, it is difficult to design a new transformation system because no selection markers and promoters are available. in this study, zeocin (400 microg/ml) was demonstrated to inhibit the growth of c. rugosa. the dominant selectable marker bleomycin-resistant determinant (ble) gene containing five cug codons in an open-reading frame of 375 bp was syn ...	2003	12459243
general trend of lipase to self-assemble giving bimolecular aggregates greatly modifies the enzyme functionality.	three microbial lipases (those from candida rugosa, humicola lanuginosa, and mucor miehei) have been found to exhibit a tendency to form bimolecular aggregates in solution even at very low enzyme concentrations (44 microg/ml) in the absence of a detergent, as detected by gel filtration. the monomolecular form of the enzymes was found as unique only at low enzyme concentration and in the presence of detergents. however, in the case of the lipase b from candida antarctica, no bimolecular form coul ...	2003	12523838
polymerization of propyl malolactonate in the presence of candida rugosa lipase.	to gain better insight into mechanistic features of enzyme-catalyzed malolactonate polymerization, reactions with propyl malolactonate were analyzed while varying enzyme concentration, reaction media composition, and reaction temperature. monomer conversion and product molecular weights were characterized by (1)h nmr and maldi-tof ms, respectively. a high extent of thermal polymerization of propyl malolactonate was observed, while the polymer chain length in all reactions was controlled by the e ...	2003	12523841
activity of candida rugosa lipase immobilized on gamma-fe2o3 magnetic nanoparticles.	we report the stability and enzymatic activity of candida rugosa lipase (e.c.3.1.1.3) immobilized on gamma-fe2o3 magnetic nanoparticles. the immobilization strategies were either reacting the enzyme amine group with a nanoparticle surface acetyl, or amine groups. in the former, the enzyme was attached through a c=n bond, while in the latter it was connected using glutaraldehyde. afm images show an average particle size of 20 +/- 10 nm after deconvolution. the enzymatic activity of the immobilize ...	2003	12580578
crystallization and preliminary x-ray diffraction studies of two different crystal forms of the lipase 2 isoform from the yeast candida rugosa.	the yeast candida rugosa produces several closely related lipases which show a high degree of sequence identity (between 77 and 88% for pairs of proteins). despite this high sequence identity, they exhibit markedly different substrate specificities, indicating that subtle structural differences may produce significant functional changes. isoform 2 (lip2) has been crystallized using the hanging-drop vapour-diffusion method at 291 k. diffraction-quality crystals have been obtained from two differe ...	2003	12595707
behavior of silica aerogel networks as highly porous solid solvent media for lipases in a model transesterification reaction.	highly porous silica aerogels with differing balances of hydrophobic and hydrophilic functionalities were studied as a new immobilization medium for enzymes. two types of lipases from candida rugosa and burkholderia cepacia were homogeneously dispersed in wet gel precursors before gelation. the materials obtained were compared in a simple model reaction: transesterification of vinyl laurate by 1-octanol. to allow a better comparison of the hydrophobic/hydrophilic action of the solid, very open a ...	2003	12616634
impact of ionic liquid physical properties on lipase activity and stability.	lipase activity and stability was investigated in dialkylimidazolium and pyrrolidinium-based ionic liquids with a variety of anions including hexafluorophosphate, acetate, nitrate, methanesulfonate, trifluoroacetate, and trifluoromethylsulfonate. the initial rate of lipase-catalyzed transesterification of methyl methacrylate in these ionic liquids and several organic solvents was examined as well as the polytransesterification of divinyl adipate and 1,4-butanediol. free lipase (candida rugosa) c ...	2003	12670234
[high expression of lip1 in pichia pastoris].	the gene of lip1, the most important isoenzyme of candida rugosa lipase (crl), was artificially synthesized according to its mature peptide sequence. it consisted of 20 codons of preference in pichia pastoris. the artificial gene was cloned into methanol-inducible expression vector ppiczalphaa, and constitutive expression vector pgapzalphaa, respectively. the linearized recombinant plasmids were transformed into chromosome of pichia pastoris smd1168h strain by electroporation. the abilities of e ...	2003	12673392
effect of reaction parameters on synthesis of citronellyl methacrylate by lipase-catalyzed transesterification.	the methacrylate ester of citronellol was synthesized using various lipases as catalyst. the effect of different reaction parameters such as amount of lipase, solvent, temperature, and acylating agent on the conversion of citronellol to citronellyl methacrylate was studied. methyl methacrylate, vinyl methacrylate, and 2,3-butanedione mono-oxime methacrylate were used as acylating agents. porcine pancreatic lipase (ppl), candida rugosa lipase (crl), and pseudomonas cepacia lipase (amano-ps) were ...	2003	12675563
gelatin blends with alginate: gels for lipase immobilization and purification.	blends of natural polysaccharide sodium alginate (5%) with gelatin (3%) cross-linked with glutaraldehyde provide beads with excellent compressive strength (8 x 10(4) pa) and regular structure on treatment with calcium chloride. lipases from porcine pancreas, pseudomonas cepacia, and candida rugosa were immobilized in such a blend with excellent efficiency. the immobilized enzymes were stable and were reused several times without significant loss of enzyme activity both in aqueous and reverse mic ...	2003	12675601
covalent coupling method for lipase immobilization on controlled pore silica in the presence of nonenzymatic proteins.	candida rugosa lipase was covalently immobilized on silanized controlled pore silica previously activated with glutaraldehyde in the presence of nonenzymatic proteins. this strategy is suggested to protect the enzyme from aggregation effects or denaturation that occurs as a result of the presence of silane precursors used in the formation of the silica matrix. the immobilization yield was evaluated as a function of the lipase loading and the additive type (albumin and lecithin) using statistical ...	2003	12790642
purification of conjugated linoleic acid isomers through a process including lipase-catalyzed selective esterification.	a mixture of conjugated linoleic acids (clas) was prepared by alkali conjugation of high purity linoleic acid. the preparation contained 45.1 wt% cis-9, trans-11 (c9,t11)-cla, 46.8 wt% trans-10, cis-12 (t10,c12)-cla, and 5.3 wt% other clas. a process comprising candida rugosa lipase-catalyzed selective esterification with lauryl alcohol, molecular distillation, and urea adduct fractionation under strict conditions in ethanol was very effective for purification of c9,t11- and t10,c12-clas. in par ...	2003	12843679
lipase-catalyzed enantioselective esterification of (s)-naproxen hydroxyalkyl ester in organic media.	a lipase-catalyzed, enantioselective esterification process in organic solvents was developed for the synthesis of (s)-naproxen hydroxyalkyl ester. with the selection of lipase (candida rugosa lipase) and reaction medium (isooctane and cyclohexane), a high enantiomeric ratio of > 100 for the enzyme was obtained. 1,4-butanediol was the best acyl acceptor. the carbon chain length of the alcohol had a major effect on the enzyme activity and enantioselectivity of lipase-catalyzed esterification.	2003	12882564
insights from molecular dynamics simulations into ph-dependent enantioselective hydrolysis of ibuprofen esters by candida rugosa lipase.	an interesting observation was found during our continued studies on the hydrolysis of ibuprofen esters by candida rugosa lipase (crl). an important role is played by ph in the stereospecific hydrolysis of these esters. the flap region of crl plays a significant role in the access of the substrate to the active site of the enzyme. at ph 5.6, 48% of the methyl ester and 5% of the butyl ester of ibuprofen were hydrolysed in 5.5 h, whereas at ph 7.2, 9% of methyl ester and 45% of the butyl ester of ...	2003	14983082
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
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
chemical modification of lipases with various hydrophobic groups improves their enantioselectivity in hydrolytic reactions.	semi-purified lipases from candida rugosa, pseudomonas cepacia and alcaligenes sp. were chemically modified with a wide range of hydrophobic groups such as benzyloxycarbonyl, p-nitrobenzyloxycarbonyl, p-methoxybenzyloxycarbonyl, t-butoxycarbonyl, lauroyl and acetyl moieties. the candida rugosa lipase my modified with the benzyloxycarbonyl group (modification ratio = 84%) brought about a 15-fold increase in enantioselectivity (e value) towards the hydrolysis of racemic butyl 2-(4-ethylphenoxy)pro ...	2003	12882312
lipase-catalyzed acidolysis of menhaden oil with conjugated linoleic acid: effect of water content.	the effect of the water content on the lipase-catalyzed (candida rugosa) interesterification (acidolysis) of menhaden oil with conjugated linoleic acid was studied for amounts of added water ranging from 0-4% (w/w). the rate of the acidolysis reaction increased with increasing water content, but the corresponding percentage of n-3 fatty acids liberated also increased. the implications of water content for minimization of the release of n-3 fatty acid residues while maximizing incorporation of cl ...	2002	12115120
differentiation between lutein monoester regioisomers and detection of lutein diesters from marigold flowers (tagetes erecta l.) and several fruits by liquid chromatography-mass spectrometry.	liquid chromatography-atmospheric pressure chemical ionization mass spectrometry (lc-apcims) was employed for the identification of eight lutein monoesters, formed by incomplete enzymatic saponification of lutein diesters of marigold (tagetes erecta l.) by candida rugosa lipase. additionally, the main lutein diesters naturally occurring in marigold oleoresin were chromatographically separated and identified. the lc-ms method allows for characterization of lutein diesters occurring as minor compo ...	2002	11754543
esterification of fatty acids using nylon-immobilized lipase in n-hexane: kinetic parameters and chain-length effects.	the esterification of long-chain fatty acids in n-hexane catalyzed by nylon-immobilized lipase from candida rugosa has been investigated. butyl oleate (22 carbon atoms), oleyl butyrate (22 carbon atoms) and oleyl oleate (36 carbon atoms) were produced at maximum reaction rates of approximately equal to 60 mmol h(-1) g(-1) immobilized enzyme when the substrates were present in equimolar proportions at an initial concentration of 0.6 mol l(-1). the observed kinetic behavior of all the esterificati ...	2002	11755985
factors affecting the resolution of dl-menthol by immobilized lipase-catalyzed esterification in organic solvent.	among 10 lipases tested, candida rugosa lipase exhibited the best ability to catalyze the resolution of dl-menthol in organic solvent. the lipase was immobilized on different carriers, and the experiment was carried out with different acyl donors. the high yield and optical purity of the product were achieved in cyclohexane with valeric acid as acyl donor using c. rugosa lipase immobilized on deae-sephadex a-25. the conversion of dl-menthol depended on the water content of immobilized lipase and ...	2002	11782192
effect of acyl chain length and branching on the enantioselectivity of candida rugosa lipase in the kinetic resolution of 4-(2-difluoromethoxyphenyl)-substituted 1,4-dihydropyridine 3,5-diesters.	since 2,6-dimethyl-4-aryl-1,4-dihydropyridine 3,5-diesters themselves are not hydrolyzed by commercially available hydrolases, derivatives with spacers containing a hydrolyzable group were prepared. seven acyloxymethyl esters of 5-methyl- and 5-(2-propoxyethyl) 4-[2-(difluoromethoxy)phenyl]-2,6-dimethyl-1,4-dihydro-3,5-pyridinedicarboxylate were synthesized and subjected to candida rugosa lipase (crl) catalyzed hydrolysis in wet diisopropyl ether. a methyl ester at the 5-position and a long or b ...	2002	11798310
novel lipase-catalysed highly selective acetylation studies on d-arabino- and d-threo-polyhydroxyalkyltriazoles.	capabilities of lipases from candida antarctica, candida rugosa and porcine pancreas have been evaluated for regioselective acetylation of 2-phenyl-4-(d-arabino-tetrahydroxybutyl)-2h-1,2,3-triazole, 2-phenyl-4-(d-arabino-o-1',2'-isopropylidene-3',4'-dihydroxybutyl)-2h-1,2,3-triazole and 2-phenyl-4-(d-threo-trihydroxypropyl)-2h-1,2,3-triazole, precursors for the synthesis of triazolylacyclonucleosides. c. antarctica lipase and porcine pancreatic lipase exhibited exclusive selectivity for the acet ...	2002	11836103
synthesis of optically active vicinal fluorohydrins by lipase-catalyzed deracemization.	three microbial lipases have been used to deracemize trans-2-fluorocycloalkanols 2 both by hydrolysis of the corresponding acetates 3 or chloroacetates 4 and by esterification of the fluorohydrins 2 using vinyl acetate and vinyl chloroacetate, respectively. pseudomonas cepacia lipase was the most selective for the six- and the seven-membered-ring compounds, while the lipase from candida rugosa was most useful for the eight-membered-ring compounds. both lipases transform the (r)-enantiomers prefe ...	2002	11975561
esterification activity and stability of candida rugosa lipase immobilized into chitosan.	microbial lipase from candida rugosa immobilized into porous chitosan beads was tested for esterification selectivity with butanol and different organic acids (c2-c12), and butyric acid and different aliphatic alcohols (c2-c10). after 24 h, the acids tested achieved conversions of about 40-45%. acetic acid was the only exception, and in this case butanol was not consumed. different alcohols led to butyric acid conversions >40%, except for ethanol, in which case butyric acid was converted only 26 ...	2002	12018318
multiple mutagenesis of non-universal serine codons of the candida rugosa lip2 gene and biochemical characterization of purified recombinant lip2 lipase overexpressed in pichia pastoris.	the 17 non-universal serine codons (ctg) in the candida rugosa lip2 gene have been converted into universal serine codons (tct) by overlap extension pcr-based multiple site-directed mutagenesis. an active recombinant lip2 lipase was overexpressed in pichia pastoris and secreted into the culture medium. the recombinant lip2 showed distinguishing catalytic activities when compared with recombinant lip4 and commercial c. rugosa lipase. the purified enzyme showed optimum activity at ph 7 and a broad ...	2002	12020350
microwave-assisted rapid characterization of lipase selectivities.	a rapid screening procedure for characterization of lipase selectivities using microwaves was developed. the rate of reaction of various commercial lipases (porcine pancreas, mucor miehei, candida rugosa, pseudomonas cepacia) as well as lipases from laboratory isolates-bacillus stearothermophilus and burkholderia cepacia rgp-10 for triolein hydrolysis was 7- to 12-fold higher in a microwave oven as compared to that by ph stat. the esterification of sucrose/methanol and ascorbic acid with differe ...	2002	12062110
lipase-assisted generation of 2-methyl-3-furanthiol and 2-furfurylthiol from thioacetates.	enzymatic hydrolysis of s-3-(2-methylfuryl) thioacetate and s-2-furfuryl thioacetate using lipase from candida rugosa produced 2-methyl-3-furanthiol and 2-furfurylthiol, respectively. when reactions were carried out at room temperature and ph 5.8, 2-methyl-3-furanthiol was produced in a optimal yield of 88% after 15 min of reaction, whereas 2-furfurylthiol was obtained in a yield of 80% after 1 h of reaction time. enzymatic hydrolysis was also performed in n-hexane, n-pentane, and water/propylen ...	2002	12083888
enantiomeric resolution of 2-aryl propionic esters with hyperthermophilic and mesophilic esterases: contrasting thermodynamic mechanisms.	the enantiomeric resolution of 2-aryl propionic esters by hyperthermophilic and mesophilic esterases was found to be governed by contrasting thermodynamic mechanisms. entropic contributions predominated for mesophilic esterases from candida rugosa and rhizomucor miehei, while enthalpic forces controlled this resolution by the esterase from the extremely thermoacidophilic archaeon, sulfolobus solfataricus p1. this disparity in thermodynamic mechanism can be attributed to the differences in confor ...	2002	12105890
immobilization of lipase using hydrophilic polymers in the form of hydrogel beads.	the purpose of this study was to immobilize lipase (triacylglycerol ester hydrolase, e.c. 3.1.1.3) from candida rugosa using various polymers in the form of beads, to evaluate enzyme loading, leaching, and activity; and to characterize the beads. agarose, alginate, and chitosan were the polymers selected to immobilize lipase by entrapment. agarose beads exhibited undesirable swelling in the leaching and activity medium and the polymer was not used further. alginate or chitosan beads were prepare ...	2002	12109688
molecular weight and degree of deacetylation effects on lipase-loaded chitosan bead characteristics.	the effects of the molecular weight (mw) and degree of deacetylation (dd) of chitosan on chitosan hydrogel beads were characterized, and the entrapment efficiency, release of entrapped lipase, and activity of immobilized candida rugosa lipase were investigated. fresh and freeze-dried beads were characterized. a solution of lipase was prepared in a 1.5% (w/v) chitosan and 1% (v/v) acetic acid medium, and then dropped into a tripolyphosphate solution to prepare the beads. the release studies were ...	2002	12109689
carotenol fatty acid esters: easy substrates for digestive enzymes?	to study the specificity of gastric lipases on carotenoid mono- and diesters, an enzymatic assay was applied. digestions were carried out in phosphate buffer at ph 7.4 and 37 degrees c. as substrates we employed oleoresins from marigold (tagetes erecta l.; lutein diesters), red paprika (capsicum annuum l., mainly capsanthin diesters), papaya (carica papaya l.; beta-cryptoxanthin esters), and loquat (eriobotrya japonica lindl.; beta-cryptoxanthin esters) as well as retinyl palmitate. these were r ...	2002	12128058
enzymatic synthesis of dextran-containing hydrogels.	dextran, a natural glucose-containing polysaccharide, has been acylated by proleather fg-f and lipase ay, a protease and lipase from bacillus sp. and candida rugosa, respectively, in anhydrous dimethylsulfoxide in the presence of vinyl acrylate (va). the efficiency of the reaction in the presence of proleather fg-f and the isolated yields were ca. 71% and 45%, respectively. dextran derivatized with va (dext70-va) was characterized by gel permeation chromatography and its structure was establishe ...	2002	12162328
formal total synthesis of (+)-macrosphelide a based on regioselective hydrolysis using lipase.	three kinds of seco-macrosphelide a congeners, (4r,5s,10r,11s,15s)-6, (4r,5s,9s,14r,15s)-7 and (3s,8r,9s,14r,15s)-8 were chemically synthesized, and they were exposed to the lipase of-360 from candida rugosa to give three hydroxy carboxylic acids, respectively. macrolactonization of the hydroxy acid (4r,5s,10r,11s)-18 derived from (4r,5s,10r,11s,15s)-6 gave 12-membered lactone (19) in 47% overall yield from 6, while that of the seco-acid (4) derived from (4r,5s,9s,14r,15s)-7 afforded (-)-dibenzy ...	2002	12036034
blocking the tunnel: engineering of candida rugosa lipase mutants with short chain length specificity.	the molecular basis of chain length specificity of candida rugosa lipase 1 was investigated by molecular modeling and site-directed mutagenesis. the synthetic lip1 gene and the lipase mutants were expressed in pichia pastoris and assayed for their chain length specificity in single substrate assays using triglycerides as well as in a competitive substrate assay using a randomized oil. mutation of amino acids at different locations inside the tunnel (p246f, l413f, l410w, l410f/s300e, l410f/s365l) ...	2002	12200542
antimicrobial and anti-lipase activity of quercetin and its c2-c16 3-o-acyl-esters.	neither quercetin (q), nor 3-o-acylquercetines, up to 100 microg/ml, had any significant activity on selected gram-positive strains (staphylococcus aureus, bacillus subtilis, listeria ivanovi, listeria monocytogenes, listeria serligeri), gram-negative strains (escherichia coli, shigella flexneri, shigella sonnei, salmonella enteritidis, salmonella tiphymurium) and yeasts (candida albicans and candida glabrata). in addition, we confirmed the known anti-hiv activity of q (80% inhibition at 40 micr ...	2002	11741775
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
polyfungal candidaemia due to candida rugosa and candida pelliculosa in a haemodialyzed neonate.		2002	12195892
fine separation and characterization of candida rugosa lipase isoenzymes.	commercial candida rugosa lipase has been separated into two distinct fractions (crla and crlb) by anion-exchange chromatography. as analyzed on sds-polyacrylamide gel electrophoresis, crla and crlb are homogenous. at high ionic strength, crla and crlb have similar hydrophobicity and uv spectra, suggesting that the open extent of the large hydrophobic pockets of crla and crlb may be similar. at low ionic strength, using "hydrophobic interfacial affinity chromatography", both crla and crlb have b ...	2002	12362407
hydrolysis of steryl esters by a lipase (lip 3) from candida rugosa.	a well-known lipase, lip 3 of candida rugosa, was purified to homogeneity from a commercial lipase preparation, using hydrophobic interaction and anion exchange chromatography. lip 3, which has been reported to act on cholesteryl esters, was also found to be active on plant-derived steryl esters. lip 3 had optimal activity at ph 5-7 and below 55 degrees c. it was able to hydrolyse steryl esters totally in a clear micellar aqueous solution. however, the action on a dispersed colloidal steryl este ...	2002	12382052
investigation of lipase-catalysed hydrolysis of naproxen methyl ester: use of nmr spectroscopy methods to study substrate-enzyme interaction.	(+/-)-2-(6-methoxy-2-naphthyl)propionic acid methyl ester (methyl ester of naproxen), the precursor of therapeutically important nonsteroidal anti-inflammatory drugs (nsaids) was enantioselectively hydrolysed using as biocatalyst candida rugosa lipase. in research aimed at studying the structure-activity relationship (sar), nmr spectroscopy methods were employed to identify which naproxen molecular moiety was essential to the substrate-enzyme interaction. the experimental results, in agreement w ...	2002	12392706
regioselective enzymatic hydrolysis of acetylated pyranoses and pyranosides using immobilised lipases. an easy chemoenzymatic synthesis of alpha- and beta-d-glucopyranose acetates bearing a free secondary c-4 hydroxyl group.	protected sugars with only one free hydroxyl group are useful building blocks for the synthesis of a large number of glycoderivatives. in order to avoid the problems of the classical chemical synthesis, we studied the regioselective enzymatic hydrolysis of different fully acetylated glycopyranoses and glycopyranosides. the main challenge was to obtain the hydrolysis of the substrates in only one position, with high regioselectivity, while avoiding any further hydrolysis towards partially acetyla ...	2002	12423962
[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
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
influence of the conformational flexibility on the kinetics and dimerisation process of two candida rugosa lipase isoenzymes.	we have investigated the interfacial activation process of two isoenzymes from candida rugosa (lip1 and lip3) using triacetin as substrate. kinetics were coupled to inhibition experiments in order to analyse the transition between the open and closed conformers. this process was slow, particularly for lip1, in the absence of an interface provided by the substrate or a detergent. dimers of lip3 were also purified and their catalytic action was closer to that of a typical esterase. in spite of the ...	2001	11457462
lipase-catalysed hydrolysis of short-chain substrates in solution and in emulsion: a kinetic study.	we have studied the enzymatic hydrolysis of solutions and emulsions of vinyl propionate, vinyl butyrate and tripropionin by lipases of various origin and specificity. kinetic studies of the hydrolysis of short-chain substrates by microbial triacylglycerol lipases from rhizopus oryzae, mucor miehei, candida rugosa, candida antarctica a and by (phospho)lipase from guinea-pig pancreas show that these lipolytic enzymes follow the michaelis-menten model. surprisingly, the activity against solutions o ...	2001	11750885
[studies on lipase production from candida rugosa].	we studied some factors affecting the lipase production from candida rugosa, they mainly included medium compositions and culture condition. the result showed that the optimal medium compositions for lipase production are 0.1% glucose 4.0% olive oil (carbon source), 0.3% nh4no3(nitrogen source), 1.2% k2hpo4 and 0.4% mgso4.7h2o. and the optimal culture condition is initial ph6.5, temperature 30 degrees c, agitation 180 r/min and time 60 h. as a result, and the lipase activity could reach 19.5 u/m ...	2001	11330177
rice straw as a support for immobilization of microbial lipase.	candida rugosa lipase was covalently immobilized on rice straw activated with glutaraldehyde using poly(ethylene glycol) (peg) as the stabilizing agent. the effects of peg molecular weight and enzyme loading were studied according to a full 2(2) factorial design. higher immobilization yields (>70%) were attained when the lipase loading was 95 units/mg of dry support, independent of peg molecular weight. all derivatives showed high hydrolytic and synthetic activities. this work provides prelimina ...	2001	11735441
recombinant expression and characterization of the candida rugosa lip4 lipase in pichia pastoris: comparison of glycosylation, activity, and stability.	although candida rugosa utilizes a nonuniversal serine codon (cug) for leucine, it is possible to express lipase genes (lip) in heterologous systems. after replacing the 19 cug codons in lip4 with serine codons by site-directed mutagenesis, a recombinant lip4 was functionally overexpressed in pichia pastoris in this study. this recombinant glycosylated lipase was secreted into the culture medium with a high purity of 100 mg/liter in a culture broth. purified recombinant lip4 had a molecular mass ...	2001	11368188
effect of water activity and immobilization on fatty acid selectivity for esterification reactions mediated by lipases.	the effect of water activity (a(w)) and immobilization on fatty acid (fa) selectivity of burkholderia (formerly pseudomonas) cepacia, rhizomucor miehei, candida antarctica (type b), and candida rugosa lipases in esterification reactions was determined. studies were based on measuring ester formation in multicompetitive reaction mixtures containing either the homologous series of even carbon number n-chain saturated fa (c4-c18) or a series of n-chain (un)saturated fa (c18:x, where x = 0-3 double ...	2001	11536145
immobilization of candida rugosa lipase on colloidal gas aphrons (cgas).	a novel technique for immobilization of candida rugosa lipase onto anionic colloidal gas aphrons (cgas) is described. cgas are spherical microbubbles (10-100 microm) composed of an inner gas core surrounded by a surfactant shell. in this initial study, greater than 80% lipase (w/w) was effectively retained on the cgas. leakage of protein from the cgas and the activity of the adsorbed lipase decreased with increasing enzyme loading; this indicates that multilayers of lipase may be adsorbing onto ...	2001	11400100
study of lipase-catalyzed hydrolysis of some monoterpene esters.	studies of the hydrolysis of bornyl, citronellyl, geranyl, and terpenyl acetates by commercially available lipases of candida rugosa, rhizopus arrhizus, and mucor miehei are presented. the hydrolysis of these monoterpene esters is investigated at various temperatures and phs, and the time dependence of the percentage of esters hydrolysed is studied. the catalytic activities of the lipases in hydrolysing the esters are compared and, overall, it is observed that under the experimental conditions u ...	2001	11400729
lipase-catalyzed chemo- and enantioselective acetylation of 2-alkyl/aryl-3-hydroxypropiophenones.	the chemo- and enantioselective capabilities of porcine pancreatic lipase (ppl) in tetrahydrofuran, and candida rugosa lipase (crl) in diisopropyl ether have been investigated for the acetylation of racemic 2-alkyl/aryl-3-hydroxypropiophenones, which are important precursors in the synthesis of biologically active chromanones and isoflavanones. a highly chemoselective acetylation of primary hydroxy group in preference to phenolic hydroxy group leading to the formation of enantiomerically enriche ...	2001	11557352