| optimization of the hydrolysis of safflower oil for the production of linoleic acid, used as flavor precursor. | commercial lipases, from porcine pancreas (ppl), candida rugosa (crl), and thermomyces lanuginosus (lipozyme tl im), were investigated in terms of their efficiency for the hydrolysis of safflower oil (so) for the liberation of free linoleic acid (la), used as a flavor precursor. although ppl, under the optimized conditions, showed a high degree of hydrolysis (91.6%), its low tolerance towards higher substrate concentrations could limit its use for so hydrolysis. in comparison to the other invest ... | 2015 | 26904663 |
| design of biocompatible immobilized candida rugosa lipase with potential application in food industry. | biocatalysts are a promising alternative for the production of natural flavor compounds. candida rugosa lipase (crl) is a particularly important biocatalyst owing to its remarkable efficiency in both hydrolysis and synthesis. however, additional stabilization is necessary for successful industrial implementation. this study presents an easy and time-saving method for immobilizing this valuable enzyme on hydroxyapatite (hap), a biomaterial with high protein-binding capacity. | 2016 | 26801832 |
| optimization and modeling for the synthesis of sterol esters from deodorizer distillate by lipase-catalyzed esterification. | in this paper, cotton seed oil deodorizer distillate (csodd), was recovered to obtain fatty acid sterol ester (fase), which is one of the biological activated substances added as human therapeutic to lower cholesterol. esterification reactions were carried out using candida rugosa lipase (crl) as catalyst, and the conversion of phytosterol was optimized using response surface methodology (rsm). the highest conversion (90.8±0.4%) was reached at 0.84 wt% enzyme load, 1:25 solvent/csodd mass ratio, ... | 2016 | 26757412 |
| zinc oxide nanoparticles supported lipase immobilization for biotransformation in organic solvents: a facile synthesis of geranyl acetate, effect of operative variables and kinetic study. | the present study describes grafting of zinc oxide (zno) nanoparticles with polyethyleneimine (pei) followed by modification with glutraldehyde used as the bridge for binding the enzyme to support. the prepared nanocomposites were then characterized using fourier transform infrared spectroscopy, thermogravimetric analysis, and transmission electron microscopy, utilized for synthesis of geranyl acetate in n-hexane. among all the three prepared nanocomposites (zno + pei, zno + pei + saa, zno + pei ... | 2016 | 26749293 |
| properties, structure, and applications of microbial sterol esterases. | according to their substrate preferences, carboxylic ester hydrolases are organized in smaller clusters. among them, sterol esterases (ec 3.1.1.13), also known as cholesterol esterases, act on fatty acid esters of cholesterol and other sterols in aqueous media, and are also able to catalyze synthesis by esterification or transesterification in the presence of organic solvents. mammalian cholesterol esterases are intracellular enzymes that have been extensively studied since they are essential in ... | 2016 | 26743653 |
| the isolation of candida rugosa and candida mesorugosa from clinical samples in ghana. | members of the candida rugosa species complex have been described as emerging fungal pathogens and are responsible for a growing number of candida infections. in this communication we report the isolation of candida rugosa and candida mesorugosa in ghana. to the best of our knowledge this is the first description of this species complex from a clinical setting in africa.the isolates were identified on the basis of their rrna gene internal transcribed spacer (its) sequences. for one isolate, obta ... | 2016 | 26705831 |
| improvement of catalytic activity of candida rugosa lipase in the presence of calix[4]arene bearing iminodicarboxylic/phosphonic acid complexes modified iron oxide nanoparticles. | in the present study, iron oxide magnetite nanoparticles, prepared through a co-precipitation method, were coated with phosphonic acid or iminodicarboxylic acid derivatives of calix[4]arene to modulate their surfaces with different acidic groups. candida rugosa lipase was then directly immobilized onto the modified nanoparticles through sol-gel encapsulation. the catalytic activities and enantioselectivities of the two encapsulated lipases in the hydrolysis reaction of (r/s)-naproxen methyl este ... | 2016 | 26698535 |
| overexpression of candida rugosa lipase lip1 via combined strategies in pichia pastoris. | in this study, combined strategies were employed to heterologously overexpress candida rugosa lipase lip1 (crl1) in a pichia pastoris system. the lip1 gene was systematically codon-optimized and synthesized in vitro. the lip1 activity of a recombinant strain harboring three copies of the codon-optimized lip1 gene reached 1200 u/ml in a shake flask culture. higher lipase activity, 1450 u/ml, was obtained using a five copy number construct. co-expressing one copy of the ero1p and bip chaperones wi ... | 2016 | 26672457 |
| modulation of the thermostability and substrate specificity of candida rugosa lipase1 by altering the acyl-binding residue gly414 at the α-helix-connecting bend. | candida rugosa lipase1 (lip1) is widely used in industrial applications. optimizing its catalytic performance is still a challenging goal for protein engineers. mutagenesis of key residues in the active site of the enzyme may provide an effective strategy for enhancing stability and altering substrate specificity. in this study, multiple sequence alignment and structural analysis revealed that the acyl-binding residue, gly414, of lip1, which is located at a bend connecting α-helixes, was the non ... | 2016 | 26672446 |
| esterification of oleic acid with methanol by immobilized lipase on wrinkled silica nanoparticles with highly ordered, radially oriented mesochannels. | mesoporous silica nanoparticles with a wrinkled structure (wrinkled silica nanoparticles, wsns) having highly ordered, radially oriented mesochannels were synthesized by a solvothermal method. the method used a mixture of cyclohexane, ethanol, and water as solvent, tetraethoxysilane (teos) as source of inorganic silica, ammonium hydroxide as hydrolysis additive, cetyltrimethylammonium bromide (ctab) as surfactant, and polyvinylpyrrolidone (pvp) as stabilizing agent of particle growth. particle s ... | 2016 | 26652346 |
| bead milling for lipid recovery from thraustochytrid cells and selective hydrolysis of schizochytrium dt3 oil using lipase. | marine microalgae present a renewable alternative source for sustainable production of omega-3 fatty acids, as compared to conventional sources such as krill oil and fish oil. in this study, we optimised a method for lipid extraction from marine thraustochytrids using a bead mill and enzymatic concentration of omega-3 fatty acids from the thraustochytrid oil. the optimised lipid extraction conditions were, bead size 0.4-0.6μm, 4500rpm, 4min of processing time at 5g biomass concentration. the max ... | 2016 | 26519698 |
| immobilized lipase on core-shell structured fe3o4-mcm-41 nanocomposites as a magnetically recyclable biocatalyst for interesterification of soybean oil and lard. | a core-shell structured fe3o4-mcm-41 nanocomposite was prepared by means of a surfactant-directed sol-gel process. candida rugosa lipase was then bound to the magnetic core-shell material by using glutaraldehyde as a cross-linking reagent. the as-prepared fe3o4-mcm-41 support and the immobilized lipase were characterized in detail using enzyme activity assays, tem, xrd, ftir, vsm and nitrogen adsorption-desorption techniques. results showed that the magnetite nanoparticles were coated with the m ... | 2016 | 26471683 |
| rare yeasts causing fungemia in immunocompromised and haematology patients: case series from delhi. | systemic fungal infection related to fluconazole-resistant yeasts are emerging in immunocompromised patients. in this case-series, we report eight cases of fungemia caused by trichosporon spp. (2), stephanoascus ceferrii (1), kodamaea ohmeri (1), pichia kutrawersi (2), candida rugosa (1) and candida lusitianae (1) in immunocompromised patients. all the yeasts except (trichosporon asahii) were sequenced. as these rare species are inherently resistant to antifungal agents and they may lead to the ... | 2015 | 26470968 |
| carbohydrate base co-polymers as an efficient immobilization matrix to enhance lipase activity for potential biocatalytic applications. | in the present study, we have synthesized biocompatible hybrid blend of cellulosic polymers of hydroxypropyl-methyl-cellulose (hpmc) and chitosan (chy) for the immobilization of candida rugosa lipase (crl). the immobilized biocatalyst hpmc:chy:crl was subjected for characterization such as sem, tga, water content analysis, lipase activity, specific activity and protein content analysis. the kinetic parameter study (rmax/km) demonstrated improved biocatalytic activity of lipase after immobilizati ... | 2015 | 26428176 |
| optimization of an indirect enzymatic method for the simultaneous analysis of 3-mcpd, 2-mcpd, and glycidyl esters in edible oils. | we developed a novel, indirect enzymatic method for the analysis of fatty acid esters of 3-monochloro-1,2-propanediol (3-mcpd), 2-monochloro-1,3-propanediol (2-mcpd), and glycidol (gly) in edible oils and fats. using this method, the ester analytes were rapidly cleavaged by candida rugosa lipase at room temperature for 0.5 h. as a result of the simultaneous hydrolysis and bromination steps, 3-mcpd esters, 2-mcpd esters, and glycidyl esters were converted to free 3-mcpd, 2-mcpd, and 3-monobromo-1 ... | 2015 | 26369594 |
| chemoenzymatic kinetic resolution of (r)-malathion in aqueous media. | malathion (r,s)-diethyl-2-[(dimethoxyphosphorothioyl)sulfanyl]butanedioate is a chiral organophosphorus compound used widely as pesticide for suppression of harmful insects such as mosquitoes. it is well known that in biological systems (r)-malathion is the active enantiomer, therefore a sustainable approach could be the use of only the biologically active enantiomer. the resolution of the commercial racemic mixture to obtain the pure active enantiomer combined with a recycling of the undesired ... | 2015 | 26361495 |
| candida rugosa lipase immobilized onto acid-functionalized multi-walled carbon nanotubes for sustainable production of methyl oleate. | the chemical production of methyl oleate using chemically synthesized fatty acid alcohols and other toxic chemicals may lead to significant environmental hazards to mankind. being a highly valuable fatty acid replacement raw material in oleochemical industry, the mass production of methyl oleate via environmentally favorable processes is of concern. in this context, an alternative technique utilizing candida rugosa lipase (crl) physically adsorbed on multi-walled carbon nanotubes (mwcnts) has be ... | 2015 | 26267406 |
| harmaline and hispidin from peganum harmala and inonotus hispidus with binding affinity to candida rugosa lipase: in silico and in vitro studies. | the inhibitory effect of phenolic compounds and alkaloids of inonotus hispidus and peganum harmala on candida rugosa lipase was investigated, also, their antioxidant activities using dpph, abts and phosphomolybdenum were studied in this paper. the phenolic extracts have shown a stronger antiradical activity than the alkaloids extracts. the enzymatic inhibition produced by these extracts is described here for the first time. the results have shown that the phenolic and the alkaloid extracts are g ... | 2015 | 26151548 |
| protein-coated microcrystals from candida rugosa lipase: its immobilization, characterization, and application in resolution of racemic ibuprofen. | in this study, an economical heterogeneous biocatalyst, protein-coated microcrystals (pcmcs), was prepared from a commercial candida rugosa lipase (crl) and used for catalyzing esterification of (r, s)-ibuprofen enantiomers with isooctanol in isooctane. the main variables controlling the process (precipitating solvents, ph, saturated k2so4 solution, and water content) were optimized via single-factorial experiments. under optimum conditions, the enantiomeric excess of active s(+)-ibuprofen and t ... | 2015 | 26137875 |
| enzymatic kinetic resolution of racemic ibuprofen: past, present and future. | this review is a journey concerning the investigations of the kinetic resolution of racemic ibuprofen for the last 20 years. the relevancy of the pharmacological uses of the s( + ) enantiomer along with its higher cost compared with racemic profen are the driving forces of a variety of scientific research studies addressing the enzymatic resolution of ibuprofen through enantiomeric esterification using lipases as biocatalysts. lipases of fungal sources such as candida rugosa, rhizomucor miehei a ... | 2016 | 26121932 |
| two-step biocatalytic process using lipase and whole cell catalysts for biodiesel production from unrefined jatropha oil. | to avoid lipase deactivation by methanol in the enzymatic transesterification process, a two-step biocatalytic process for biodiesel production from unrefined jatropha oil was developed. | 2015 | 26063623 |
| conversion of crude jatropha curcas seed oil into biodiesel using liquid recombinant candida rugosa lipase isozymes. | the versatile candida rugosa lipase (crl) has been widely used in biotechnological applications. however, there have not been feasibility reports on the transesterification of non-edible oils to produce biodiesel using the commercial crl preparations, mixtures of isozymes. in the present study, four liquid recombinant crl isozymes (crl1-crl4) were investigated to convert various non-edible oils into biodiesel. the results showed that recombinant crl2 and crl4 exhibited superior catalytic efficie ... | 2015 | 26011691 |
| preparation of highly purified stearidonic acid from echium oil via an enzymatic method combined with preparative high performance liquid chromatography. | stearidonic acid (sda), an n-3 polyunsaturated fatty acid (pufa), can be obtained from plant origin oils and it can be a good source of pufa for vegetarians. sda can be easily converted to longer pufa such as docosahexaenoic acid and eicosapentaenoic acid. highly purified stearidonic acid (sda) was prepared successfully from echium oil via an enzymatic method combined with preparative high performance liquid chromatography. in the 1(st) step, sda enrichment was accomplished using candida rugosa ... | 2015 | 25994555 |
| a general method for synthesizing enzyme-polymer conjugates in reverse emulsions using pluronic as a reactive surfactant. | using aldehyde-functionalized pluronic as the reactive surfactant, enzyme-pluronic conjugates with sizes ranging from nanometers to micrometers were synthesized in reverse emulsions. compared with the direct conjugation in aqueous solution, this method gave an increased conjugation efficiency and well-controlled size of the conjugates. the versatility of this method was validated using horseradish peroxidase (hrp), candida rugosa lipase (crl) and candida antarctica lipase b (calb). the resulting ... | 2015 | 25977947 |
| biocatalytic approach for the synthesis of enantiopure acebutolol as a β₁-selective blocker. | a new chemoenzymatic route is reported to synthesize acebutolol, a selective β1 adrenergic receptor blocking agent in enantiopure (r and s) forms. the enzymatic kinetic resolution strategy was used to synthesize enantiopure intermediates (r)- and (s)-n-(3-acetyl-4-(3-chloro-2-hydroxypropoxy)phenyl)butyramide from the corresponding racemic alcohols. the results showed that out of eleven commercially available lipase preparations, two enzyme preparations (lipase a, candida antarctica, clea [cal cl ... | 2015 | 25977108 |
| candida rugosa lipase immobilization on hydrophilic charged gold nanoparticles as promising biocatalysts: activity and stability investigations. | in this work, a simple and versatile methodology to obtain two different bioconjugated systems has been developed by the immobilization of candida rugosa lipase (crl) on hydrophilic gold nanoparticles functionalized with 2-diethylaminoethanethiol hydrochloride (dea) or with sodium 3-mercapto-1-propanesulfonate (3mps), namely au-dea@crl and au-3mps@crl. both spectroscopic and morphological properties of metal nanoparticles have been deeply investigated. the enzyme loading and lipolytic activity o ... | 2015 | 25969418 |
| production and optimization of biodiesel using mixed immobilized biocatalysts in packed bed reactor. | vegetable oils are used as raw materials for biodiesel production using transesterification reaction. several methods for the production of biodiesel were developed using chemical (alkali and acidic compounds) and biological catalysts (lipases). biodiesel production catalyzed by lipases is energy and cost-saving processes and is carried out at normal temperature and pressure. the need for an efficient method for screening larger number of variables has led to the adoption of statistical experime ... | 2016 | 25940482 |
| activation and deformation of immobilized lipase on self-assembled monolayers with tailored wettability. | in this work, lipase from candida rugosa (crl) was immobilized on self-assembled monolayers (sams) with various wettabilities ranging from highly hydrophilic to highly hydrophobic by adsorption in order to clearly elucidate the interfacial activation character of lipases. the sams were made of 11-hydroxyundecane-1-thiol and 1-dodecanethiol. the adsorption behavior was monitored in situ by quartz crystal microbalance with dissipation (qcm-d), and the enzyme binding constants indicated a stronger ... | 2015 | 25929434 |
| megaporous poly(hydroxy ethylmethacrylate) based poly(glycidylmethacrylate-n-methacryloly-(l)-tryptophan) embedded composite cryogel. | one-step activation, purification, and stabilization of lipase enzyme were performed by using composite hydrophobic support at low ionic strength with increased surface area during embedding process. a novel hydrophobic poly(hydroxyethylmethacrylate) [phema] based, poly(glycidyl methacrylate-n-methacryloly-(l)-tryptophan) [pgmatrp] bead embedded composite cryogel membrane having specific surface area of 195m(2)/g was used as hydrophobic matrix for adsorption of commercial candida rugosa lipase i ... | 2015 | 25909180 |
| correction: yang, c.-h., et al. immobilization of brassica oleracea chlorophyllase 1 (boclh1) and candida rugosa lipase (crl) in magnetic alginate beads: an enzymatic evaluation in the corresponding proteins. molecules 2014, 19, 11800-11815. | | 2015 | 25905608 |
| lipase immobilization on epoxy-activated poly(vinyl acetate-acrylamide) microspheres. | poly(vinyl acetate-acrylamide) microspheres with an average diameter of 2-4μm were successfully prepared and characterized via sem and ftir. then the microspheres were modified with epoxy groups through reacting with epichlorohydrin and used as carriers to covalently immobilize candida rugosa lipase. the results revealed that agitation played an important role on epoxy activation and the immobilization ratio increased with the increase of the epoxy density. on the other hand, the specific activi ... | 2015 | 25863711 |
| enzymatic synthesis of aroma acetoin fatty acid esters by immobilized candida antarctica lipase b. | to enzymatically synthesize aroma acetoin fatty acid esters, useful as flavor and fragrance ingredients in foods. | 2015 | 25851952 |
| effect of the physicochemical properties of binary ionic liquids on lipase activity and stability. | in the present study, the lipase-catalyzed hydrolysis of p-nitrophenyl butyrate is used as a model reaction to determine the activity and stability of candida rugosa lipase in binary ionic liquids (ils). the binary ils consist of hydrophobic 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim]pf6) and a small amount of hydrophilic 1-butyl-3-methylimidazolium nitrate ([bmim]no3) or 1-butyl-3-methylimidazolium trifluoromethanesulfonate ([bmim]cf3so3) or 1-butyl-3-methylimidazolium tetrafluorobo ... | 2015 | 25841366 |
| a facile enzymatic synthesis of geranyl propionate by physically adsorbed candida rugosa lipase onto multi-walled carbon nanotubes. | in view of several disadvantages as well as adverse effects associated with the use of chemical processes for producing esters, alternative techniques such as the utilization of enzymes on multi-walled carbon nanotubes (mwcnts), have been suggested. in this study, the oxidative mwcnts prepared using a mixture of hno3 and h2so4 (1:3 v/v) were used as a supportive material for the immobilization of candida rugosa lipase (crl) through physical adsorption process. the resulting crl-mwcnts biocatalys ... | 2015 | 25837507 |
| preparation of core-shell magnetic polydopamine/alginate biocomposite for candida rugosa lipase immobilization. | a flexible, biocompatible and bioadhesive enzyme immobilizing material, which was synthesized based on the covalent assembly of biomimetic polymer and oxidized polysaccharide on magnetic nanoparticles (nps), has been developed in this feasibility study. in this work, the bio-inspired polymer, polydopamine (pda), was used to modify the well-monodispersed fe3o4 nps (mpda nps) with a controllable thickness via a dip-coating process, then the alginate di-aldehyde (ada) was covalently assembled on th ... | 2015 | 25784302 |
| enzymatic hydrolysis in an aqueous organic two-phase system using centrifugal partition chromatography. | multi-phase reaction systems, mostly aqueous organic systems, are used in enzyme catalysis to convert hydrophobic substrates which are almost insoluble in aqueous media. in this study, a centrifugal partition chromatograph is used as a compact device for enzymatic multi-phase reaction that combines efficient substrate supply to the aqueous phase and separation of both phases in one apparatus. a process design procedure to systematically select the aqueous and organic phase to achieve stable and ... | 2015 | 25773726 |
| a convenient test for lipase activity in aqueous-based solutions. | we proposed a convenient and accurate method for the measurement of lipase activity in a uniform aqueous-based substrate solution. in this work, lipase from candida rugosa was used as the model lipase to test its catalytic ability toward p-nitrophenyl palmitate (p-npp), which was suspended in a mixture of p-npp ethanol solution and buffer. an ultraviolet-visible spectrophotometer was used to efficiently measure the liberated p-nitrophenol without extraction or centrifugation. several factors tha ... | 2015 | 25765304 |
| mussel-inspired surface modification of magnetic@graphite nanosheets composite for efficient candida rugosa lipase immobilization. | by the facile adhesion way, the novel composite complex by polydopamine (pda) and magnetic graphite nanosheets (fe3o4@gnss) has been successfully synthesized. the resulting composite was characterized by means of scanning electron microscopy, transmission electron microscopy, fourier transform infrared spectra, and raman spectra, x-ray diffraction, x-ray photoelectron spectroscopy, and vibrating sample magnetometry. meanwhile, the pda functionalized fe3o4@gnss (fe3o4@gnss-pda) was applied for ca ... | 2015 | 25752766 |
| molecular dynamics investigation of the ionic liquid/enzyme interface: application to engineering enzyme surface charge. | molecular simulations of the enzymes candida rugosa lipase and bos taurus α-chymotrypsin in aqueous ionic liquids 1-butyl-3-methylimidazolium chloride and 1-ethyl-3-methylimidazolium ethyl sulfate were used to study the change in enzyme-solvent interactions induced by modification of the enzyme surface charge. the enzymes were altered by randomly mutating lysine surface residues to glutamate, effectively decreasing the net surface charge by two for each mutation. these mutations resemble succiny ... | 2015 | 25641162 |
| enzymatic synthesis of phytosterol esters catalyzed by candida rugosa lipase in water-in-[bmim]pf6 microemulsion. | a water-in-ionic liquid microemulsion ([bmim]pf6/tween20/h2o) was applied as reusable reaction medium to esterify phytosterols with fatty acid by candida rugosa lipase (crl) successfully. two kinds of commercial crls, ay30 and ays which cannot effectively catalyze esterification in conventional reaction system were found effective in the microemulsion system. effects of reaction parameters on esterification were investigated; results showed that the conversion rate of 87.9 and 95.1 % was obtaine ... | 2015 | 25575761 |
| high enantioselective novozym 435-catalyzed esterification of (r,s)-flurbiprofen monitored with a chiral stationary phase. | lipases form candida rugosa and candida antarctica were tested for their application in the enzymatic kinetic resolution of (r,s)-flurbiprofen by enantioselective esterification. successful chromatographic separation with well-resolved peaks of (r)- and (s)-flurbiprofen and their esters was achieved in one run on chiral stationary phases by high-performance liquid chromatography (hplc). in this study screening of enzymes was performed, and novozym 435 was selected as an optimal catalyst for obta ... | 2015 | 25561056 |
| improvement of the activation of lipase from candida rugosa following physical and chemical immobilization on modified mesoporous silica. | lipase from candida rugosa (crl) was chemically and physically immobilized onto four types of rod-shaped mesoporous silica (rsms). rsms prepared using surfactant p123 and poly(ethylene glycol) as co-templates was functionalized with (3-aminopropyl)triethoxysilane (aptes) to obtain p-rsms by post-synthesis grafting. tetraethoxysilane was hydrothermally co-condensed with aptes to obtain c-rsms. a two-step process using aptes and glutaraldehyde was also performed to obtain g-rsms. the effects of mo ... | 2014 | 25491828 |
| hydrogen-bonding-driven enantioselective resolution against the kazlauskas rule to afford γ-amino alcohols by candida rugosa lipase. | most lipases resolve secondary alcohols in accordance with the "kazlauskas rule" to give the r enantiomers. in a similar manner to other lipases, candida rugosa lipase (crl) exhibits r enantioselectivity towards heptan-2-ol, although the enantiomeric ratio (e) is low (e=1.6). however, unexpected enantioselectivity (i.e., s enantioselectivity, e=58) of crl towards 4-(tert-butoxycarbonylamino)butan-2-ol, which has a similar chain length to heptan-2-ol, has been observed. to develop a deeper unders ... | 2015 | 25477295 |
| wood mimetic hydrogel beads for enzyme immobilization. | wood component-based composite hydrogels have potential applications in biomedical fields owing to their low cost, biodegradability, and biocompatibility. the controllable properties of wood mimetic composites containing three major wood components are useful for enzyme immobilization. here, lipase from candida rugosa was entrapped in wood mimetic beads containing cellulose, xylan, and lignin by dissolving wood components with lipase in [emim][ac], followed by reconstitution. lipase entrapped in ... | 2015 | 25439889 |
| immobilization of candida rugosa lipase onto an eco-friendly support in the presence of ionic liquid. | candida rugosa lipase (crl) was immobilized on an eco-friendly support poly(3-hydroxybutyrate-co-hydroxyvalerate) (phbv), by physical adsorption, using different ionic liquids (ils) as immobilization additives. this was to investigate the influence of cationic core ([c4mpy]cl, [c4min]cl), of anions ([c4min]cl, [c4min]n(cn)2, [c4min]tf2n), and of cation chain length ([c2min]tf2n, [c4min]tf2n) in the immobilization process. the immobilized biocatalysts (ib) were characterized with respect to the m ... | 2015 | 25391807 |
| improvement of catalytic activity of lipase in the presence of calix[4]arene valeric acid or hydrazine derivative. | sol-gel encapsulation is a simple but powerful method to enhance the enantioselectivity of lipase-catalyzed transformations in an isooctane/aqueous buffer solution. candida rugosa lipase was encapsulated according to a sol-gel procedure in the presence and absence of calix[4]arene hydrazine or carboxylic acid derivatives with fe3o4 magnetic nanoparticles as an additive. the activity of the encapsulated lipases was evaluated for the enantioselective hydrolysis of racemic naproxen methyl ester and ... | 2015 | 25326059 |
| preparation of highly purified pinolenic acid from pine nut oil using a combination of enzymatic esterification and urea complexation. | pinolenic acid (pla) is a polyunsaturated fatty acid of plant origin. pla has been successfully enriched according to a two-step process involving lipase-catalysed esterification and urea complexation. for the first step, the fatty acids present in pine nut oil were selectively esterified with lauryl alcohol using candida rugosa lipase. under the optimum conditions of 0.1% enzyme loading, 10% additional water, and 15 °c, pla was enriched up to 43 mol% from an initial value of 13 mol% in the pine ... | 2015 | 25306361 |
| lipase immobilized catalytically active membrane for synthesis of lauryl stearate in a pervaporation membrane reactor. | a composite catalytically active membrane immobilized with candida rugosa lipase has been prepared by immersion phase inversion technique for enzymatic synthesis of lauryl stearate in a pervaporation membrane reactor. sem images showed that a "sandwich-like" membrane structure with a porous lipase-pva catalytic layer uniformly coated on a polyvinyl alcohol (pva)/polyethersulfone (pes) bilayer was obtained. optimum conditions for lipase immobilization in the catalytic layer were determined. the m ... | 2014 | 25218626 |
| enzymatic interesterification of soybean oil and methyl stearate blends using lipase immobilized on magnetic fe3o4/sba-15 composites as a biocatalyst. | the magnetic fe3o4/sba-15 composites were prepared, and treated with 3-aminopropyltriethoxysilane as a carrier material for enzyme immobilization. the immobilization of candida rugosa lipase onto the amino-functionalized fe3o4/sba-15 composite was investigated by using glutaraldehyde as a coupling reagent. the immobilized lipase was then employed as a biocatalyst for the interesterification of soybean oil and methyl stearate in a laboratory-scale operation at 45°c. various techniques, such as fo ... | 2014 | 25213444 |
| photo-controlled deactivation of immobilised lipase. | lipase from candida rugosa was immobilised on a quartz surface using an azobenzene-containing, bifunctional linker, which allows deactivation of the immobilised enzyme by irradiation with visible light. | 2014 | 25204471 |
| enhanced biocatalytic esterification with lipase-immobilized chitosan/graphene oxide beads. | in this work, lipase from candida rugosa was immobilized onto chitosan/graphene oxide beads. this was to provide an enzyme-immobilizing carrier with excellent enzyme immobilization activity for an enzyme group requiring hydrophilicity on the immobilizing carrier. in addition, this work involved a process for the preparation of an enzymatically active product insoluble in a reaction medium consisting of lauric acid and oleyl alcohol as reactants and hexane as a solvent. this product enabled the s ... | 2014 | 25127038 |
| facile synthesis of oxidic peg-modified magnetic polydopamine nanospheres for candida rugosa lipase immobilization. | a versatile method for the design of polydopamine-coated magnetic material with a brush-like structure used for candida rugosa lipase (crl) immobilization was reported in this work. first, polydopamine (pda) was coated on the surface of fe₃o₄ nanospheres (fe₃o₄ nps) with a controllable thickness via dip coating process, and crl can be immobilized on it directly via covalent bonding. subsequently, pda-functionalized fe₃o₄ nps were modified with dialdehyde polyethylene glycol (peg) to obtain the a ... | 2015 | 25117546 |
| crystal structures of ophiostoma piceae sterol esterase: structural insights into activation mechanism and product release. | sterol esterases are able to efficiently hydrolyze both sterol esters and triglycerides and to carry out synthesis reactions in the presence of organic solvents. their high versatility makes them excellent candidates for biotechnological purposes. sterol esterase from fungus ophiostoma piceae (ope) belongs to the family abh03.01 of the candida rugosa lipase-like proteins. crystal structures of ope were solved in this study for the closed and open conformations. enzyme activation involves a large ... | 2014 | 25108239 |
| immobilization of brassica oleracea chlorophyllase 1 (boclh1) and candida rugosa lipase (crl) in magnetic alginate beads: an enzymatic evaluation in the corresponding proteins. | enzymes have a wide variety of applications in diverse biotechnological fields, and the immobilization of enzymes plays a key role in academic research or industrialization due to the stabilization and recyclability it confers. in this study, we immobilized the brassica oleracea chlorophyllase 1 (boclh1) or candida rugosa lipase (crl) in magnetic iron oxide nanoparticles-loaded alginate composite beads. the catalytic activity and specific activity of the boclh1 and crl entrapped in magnetic algi ... | 2014 | 25105918 |
| biocatalytic synthesis of flavor ester "pentyl valerate" using candida rugosa lipase immobilized in microemulsion based organogels: effect of parameters and reusability. | pentyl valerate was synthesized biocatalytically using candida rugosa lipase (crl) immobilized in microemulsion based organogels (mbgs). the optimum conditions were found to be ph 7.0, temperature of 37 °c, ratio of concentration of water to surfactant (wo) of 60, and the surfactant sodium bis-2-(ethylhexyl)sulfosuccinate (aot) for mbg preparation. although kinetic studies revealed that the enzyme in free form had high affinity towards substrates (k(m) = 23.2 mm for pentanol and 76.92 mm for val ... | 2014 | 25093166 |
| kinetic resolution of profens by enantioselective esterification catalyzed by candida antarctica and candida rugosa lipases. | profens (2-arylpropionic acids) are known as one of the major nonsteroidal antiinflammatory drugs (nsaids) used in the treatment of inflammation associated with tissue injury. the inflammatory activity of profens is mainly due to their (s)-enantiomer, whereas they are commercially available not only as pure enantiomers, but as racemates as well. there are several methods widely used in order to obtain enantiomerically pure compounds, however, the kinetic resolution with the application of lipase ... | 2014 | 25080075 |
| sensitive impedimetric biosensor for direct detection of diazinon based on lipases. | two novel impedimetric biosensors for highly sensitive and rapid quantitative detection of diazinon in aqueous medium were developed using two types of lipase, from candida rugosa (microbial source) (crl) and from porcine pancreas (animal source) (ppl) immobilized on functionalized gold electrode. lipase is characterized to specifically catalyze the hydrolysis of ester functions leading to the transformation of diazinon into diethyl phosphorothioic acid (detp) and 2-isopropyl-4-methyl-6-hydroxyp ... | 2014 | 25072052 |
| enhanced catalysis and enantioselective resolution of racemic naproxen methyl ester by lipase encapsulated within iron oxide nanoparticles coated with calix[8]arene valeric acid complexes. | in this study, two types of nanoparticles have been used as additives for the encapsulation of candida rugosa lipase via the sol-gel method. in one case, the nanoparticles were covalently linked with a new synthesized calix[8]arene octa valeric acid derivative (c[8]-c4-cooh) to produce new calix[8]arene-adorned magnetite nanoparticles (np-c[8]-c4-cooh), and then np-c[8]-c4-cooh was used as an additive in the sol-gel encapsulation process. in the other case, iron oxide nanoparticles were directly ... | 2014 | 25012138 |
| preparation of polyphosphazene hydrogels for enzyme immobilization. | we report on the synthesis and application of a new hydrogel based on a methacrylate substituted polyphosphazene. through ring-opening polymerization and nucleophilic substitution, poly[bis(methacrylate)phosphazene] (pbmap) was successfully synthesized from hexachlorocyclotriphosphazene. by adding pbmap to methacrylic acid solution and then treating with uv light, we could obtain a cross-linked polyphosphazene network, which showed an ultra-high absorbency for distilled water. lipase from candid ... | 2014 | 25006790 |
| stimuli-sensitive hydrogel based on n-isopropylacrylamide and itaconic acid for entrapment and controlled release of candida rugosa lipase under mild conditions. | stimuli responsive ph- and temperature-sensitive hydrogel drug delivery systems, as those based on n-isopropylacrylamide (nipaam) and itaconic acid (ia), have been attracting much of the attention of the scientific community nowadays, especially in the field of drug release. by adjusting comonomer composition, the matrix is enabled to protect the incorporated protein in the highly acidic environment of upper gastrointestinal tract and deliver it in the neutral or slightly basic region of the low ... | 2014 | 24982870 |
| enhanced conjugation of candida rugosa lipase onto multiwalled carbon nanotubes using reverse micelles as attachment medium and application in nonaqueous biocatalysis. | three liquid phases (viz. aqueous, nonaqueous, and reverse micelles) were scrutinized as medium for attachment of the enzyme candida rugosa lipase (crl) onto multiwalled carbon nanotubes (cnts). the nanotubes were functionalized to attain carboxyl and amino groups on their surfaces before enzyme conjugation. transmission electron microscopy and fourier transformation infrared spectroscopic studies were used for characterization of the nanotubes during the course of functionalization. high enzyme ... | 2014 | 24828252 |
| production of novel "functional oil" rich in diglycerides and phytosterol esters with "one-pot" enzymatic transesterification. | diglycerides and phytosterol esters are two important functional lipids. phytosterol esters mixed with dietary diglyceride could not only influence body weight but also prevent or reverse insulin resistance and hyperlipidemia. in this study, a kind of novel "functional oil" rich in both diglycerides and phytosterol esters was prepared with "one-pot" enzymatic transesterification. first, lipase ays (candida rugosa) was immobilized on the porous cross-linked polystyrene resin beads (nka) via hydro ... | 2014 | 24815553 |
| carrier-free immobilization of lipase from candida rugosa with polyethyleneimines by carboxyl-activated cross-linking. | carrier-free immobilization of candida rugosa lipase (crl) and polymers containing primary amino groups were cross-linked using carbodiimide. to accomplish this, the free carboxyl groups of the enzyme were activated with carbodiimide-succinimide in organic medium, and then the activated proteins were cross-linked with different polyethylenimines (peis). the effect of the cross-linker chain length, the amount of added bovine serum albumin (bsa), and carbodiimide concentration on the catalytic pro ... | 2014 | 24720524 |
| catalyzed ester synthesis using candida rugosa lipase entrapped by poly(n-isopropylacrylamide-co-itaconic acid) hydrogel. | this study reports the synthesis of polymeric matrices based on n-isopropylacrylamide and itaconic acid and its application for immobilization of lipase from candida rugosa. the lipase was immobilized by entrapment method. free and immobilized lipase activities, ph and temperature optima, and storage stability were investigated. the optimum temperature for free and entrapped lipase was found to be 40 and 45 °c, while the optimum ph was observed at ph 7 and 8, respectively. both hydrolytic activi ... | 2014 | 24701136 |
| impact of the configuration of a chiral, activating carrier on the enantioselectivity of entrapped lipase from candida rugosa in cyclohexane. | lipase from candida rugosa was loaded into an amphiphilic polymer co-network (apcn) composed of the chiral poly[(r)-n-(1-hydroxybutan-2-yl) acrylamide] [p-(r)-hba] and p-(s)-hba, respectively, linked by poly(dimethylsiloxane). the nanophase-separated amphiphilic morphology affords a 38,000-fold activation of the enzyme in the esterification of 1-phenylethanol with vinyl acetate. further, the enantioselectivity of the entrapped lipase was influenced by the configuration of the chiral, hydrophilic ... | 2014 | 24682791 |
| yarrowia lipolytica lipase lip2: an efficient enzyme for the production of concentrates of docosahexaenoic acid ethyl ester. | the production of omega-3 (ω-3) polyunsaturated fatty acids (pufas) rich in cis-4,7,10,13,16,19-docosahexaenoic acid (dha) was studied using lipase-catalysed hydrolysis of a mixture of ethyl esters from tuna oil. lipases from yarrowia lipolytica (yll2), thermomyces lanuginosus (tll) and candida rugosa (crl1, crl3 and crl4) were tested. c. rugosa lipases discriminated esters on the basis of their chain length, with less affinity for γ-linolenate, 11-eicosenoate, arachidonate, epa, dpa and dha eth ... | 2014 | 24657346 |
| screening of lipase carriers for reactions in water, biphasic and pure organic solvent systems. | in bioprocesses lipases are typically used in immobilized form, irrespective of type of reaction systems, to ensure an even distribution of catalysts in water restricted media and/or to facilitate separation and reuse. in these studies we report on the selection of appropriate enzyme-carrier preparation for hydrolysis reaction in aqueous and biphasic systems and transesterification in organic solvent. for this candida rugosa lipase was bound by adsorption or covalent attachment onto various carr ... | 2014 | 24644546 |
| simultaneous production of fatty acid methyl esters and diglycerides by four recombinant candida rugosa lipase's isozymes. | in this study, the catalytic efficiency of four recombinant crl (candida rugosa lipase) isozymes (lip1-lip4) towards the production of fatty acid methyl ester (fame) was compared and evaluated as an alternative green method for industrial applications. the results indicated that the recombinant c. rugosa lip1 enzyme exhibited the highest catalytic efficiency for fame production compared to the recombinant c. rugosa lip2-lip4 enzymes. the optimal conditions were as follows: ph 7.0, methanol/soybe ... | 2014 | 24594166 |
| the role of microemulsions in lipase-catalyzed hydrolysis reactions. | the kinetics of the p-nitrophenyl butyrate hydrolysis reaction, catalyzed by candida rugosa lipase in the water-in-oil microemulsion cetyltrimethylammonium bromide/water/pentanol/hexane, was investigated. the results described in the present manuscript reveal two peculiar characteristics of the reaction: (i) the initial rate of hydrolysis is very fast and (ii) by decreasing the water content of the microemulsion, the reaction rate approaches the typical behavior of reactions performed in aqueous ... | 2014 | 24585724 |
| effects of additives on lipase immobilization in microemulsion-based organogels. | an inexpensive, facile, and environmentally benign method was developed to improve the activity and stability of candida rugosa lipase (triacylglycerol acylhydrolase) immobilized on microemulsion-based organogels (crl mbgs) via the addition of additives during immobilization. the additives used were polyethylene glycol (peg) or polysaccharides. this study is the first report on the effect of additives in crl mbgs. among the tested additives, peg produced the most improvement in the immobilized c ... | 2014 | 24497044 |
| chemical modification with functionalized ionic liquids: a novel method to improve the enzymatic properties of candida rugosa lipase. | chemical modification of lysine residues in candida rugosa lipase (crl) was carried out using five different functional ionic liquids, and about 15.4-25.0 % of the primary amino groups of lysine were modified. enzymatic properties of the native and modified crls were investigated in olive oil hydrolysis reaction. improved thermal stability, catalytic activity in organic solvents, and adaptability to temperature and ph changes were achieved compared with the native enzyme. crl modified by [cholin ... | 2014 | 24488260 |
| highly stabilized lipase in polyaniline nanofibers for surfactant-mediated esterification of ibuprofen. | lipase (lp) from candida rugosa was immobilized and stabilized in polyaniline nanofibers (panfs) via a three-step process of enzyme adsorption, precipitation, and cross-linking, which generates the final immobilization called "eapc". the activity of eapc was 5.1 and 5.9 times higher than those of lp immobilizations via enzyme adsorption (ea) and enzyme adsorption/cross-linking (eac), respectively. after incubation in an aqueous buffer under shaking (200 rpm) for 84 days, eapc maintained 74% of i ... | 2014 | 24417226 |
| study of different reaction schemes for the enzymatic synthesis of polyglycerol polyricinoleate. | different strategies for the solvent-free enzymatic production of polyglycerol polyricinoleate (pgpr) were explored in an attempt to simplify and improve the process. besides the conventional procedure (obtaining polyricinoleic acid, followed by its esterification with polyglycerol), two alternative methods are proposed: (1) reversing the synthesis order, i.e. esterification of polyglycerol with ricinoleic acid and then the condensation of ricinoleic acid with the previously obtained polyglycero ... | 2014 | 24403129 |
| removal of zn(ii) from electroplating effluent using yeast biofilm formed on gravels: batch and column studies. | present study deals with the removal of zn(ii) ions from effluent using yeast biofilm formed on gravels. | 2014 | 24397917 |
| conformation and catalytic properties studies of candida rugosa lip7 via enantioselective esterification of ibuprofen in organic solvents and ionic liquids. | enantioselective esterification of ibuprofen was conducted to evaluate the enzyme activity and ees of lipase from candida rugosa (crl7) in ten conventional organic solvents and three ionic liquids. different alcohols were tested for selecting the most suitable acyl acceptor due to the fact that the structure of alcohols (branch and length of carbon chains; location of -oh functional group) could affect the enzyme activity and ees. the results of alcohol and solvent selection revealed that 1-isoo ... | 2013 | 24381516 |
| effect of metal ions on the hydrolytic and transesterification activities of candida rugosa lipase. | in order to study the effect of metal ions on lipase activity, hydrolytic and transesterification activities of candida rugosa lipase were investigated in presence of alkali (na⁺ and k⁺), alkaline earth (ca⁺² and ba⁺²) and transition (cr⁺³, fe⁺³, co⁺², cu⁺² and ni⁺²) metal ions. maximum enhancement in hydrolytic activity of lipase was observed by ca⁺², and in transesterification activity by cr⁺³ and co⁺². the kinetics of the lipase catalyzed transesterification (methanolysis and ethanolysis) rea ... | 2013 | 24200940 |
| systematic review and new insights into the molecular characterization of the candida rugosa species complex. | recently, candida rugosa was characterized as a species complex comprising four taxa: c. rugosa sensu stricto, candida pseudorugosa, candida neorugosa and candida mesorugosa. although considered relatively rare, several clusters of candidemia due to c. rugosa complex had been reported presenting mortality rates close to 70%. in this work we discuss the systematization, phenotyping and molecular methods based on internal transcribed spacer region (its) sequencing and proteomic analyses for specie ... | 2013 | 24161727 |
| fungal genomes mining to discover novel sterol esterases and lipases as catalysts. | sterol esterases and lipases are enzymes able to efficiently catalyze synthesis and hydrolysis reactions of both sterol esters and triglycerides and due to their versatility could be widely used in different industrial applications. lipases with this ability have been reported in the yeast candida rugosa that secretes several extracellular enzymes with a high level of sequence identity, although different substrate specificity. this versatility has also been found in the sterol esterases from th ... | 2013 | 24138290 |
| two-step method of enzymatic synthesis of starch laurate in ionic liquids. | enzymatic esterification of starch with long-chain fatty acid was investigated by using ionic liquids 1-butyl-3-methylimidazolium choride ([bmim]cl) and 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim][bf4]) as reaction media. an industrial lipase produced by candida rugosa was used to modify starch with lauric acid. the effect of reaction parameters such as the lipase dosage, the molar ratio of lauric acid/anhydroglucose unit (agu) in starch, and the reaction temperature as well as the rea ... | 2013 | 24099559 |
| calix[n]arene carboxylic acid derivatives as regulators of enzymatic reactions: enhanced enantioselectivity in lipase-catalyzed hydrolysis of (r/s)-naproxen methyl ester. | candida rugosa lipase was immobilized with a sol-gel encapsulation procedure in the presence and absence of a calix[n]arene carboxylic acid derivative grafted onto magnetic nanoparticles or in the presence of the calix[n]arene carboxylic acid derivative with fe3o4 magnetic nanoparticles as an additive. through the enantioselective hydrolysis of racemic naproxen methyl ester and the hydrolysis of p-nitrophenylpalmitate, the relative enzyme activity was evaluated and tested. these results show tha ... | 2014 | 24092454 |
| improving catalytic hydrolysis reaction efficiency of sol-gel-encapsulated candida rugosa lipase with magnetic β-cyclodextrin nanoparticles. | a silica-based β-cyclodextrin was immobilized on magnetic nanoparticles to obtain a macrocyclic compound with magnetic property. then, the β-cyclodextrin-grafted magnetic nanoparticles were encapsulated with candida rugosa lipase in sol-gel matrices using alkoxysilane precursors. the catalytic activity of the encapsulated lipases was evaluated with model reactions, i.e., the hydrolysis of p-nitro-phenylpalmitate (p-npp) and the enantioselective hydrolysis of rasemic naproxen methyl ester that wa ... | 2014 | 24090713 |
| biosynthesis of sucrose-6-acetate catalyzed by surfactant-coated candida rugosa lipase immobilized on sol-gel supports. | sucrose-6-acetate is an important intermediate in the preparation of sucralose (a finest sweetener). in our study, candida rugosa lipase coated with surfactant was firstly immobilized on sol-gel supports. then, the immobilized enzyme was used in the regioselective synthesis of sucrose-6-acetate by transesterification of sucrose and vinyl acetate. the screening results revealed that tween 80 was an ideal surfactant to coat lipase immobilized in sol-gel and exhibited the highest yield of sucrose-6 ... | 2014 | 24037039 |
| synthesis of phytosteryl ester containing pinolenic acid in a solvent-free system using immobilized candida rugosa lipase. | phytosteryl ester synthesized with pinolenic acid (pla) from pine nut oil is expected to have features of both phytosterol and pla. in this study, lipase from candida rugosa (crl) was immobilized and then used to optimize conditions for synthesis of phytosteryl ester containing pla. lewatit vp oc 1600, a macroporous hydrophobic resin, was selected as the best carrier, and the optimum condition for the immobilization of crl was established. with immobilized crl prepared, synthesis of phytosteryl ... | 2013 | 23988007 |
| immobilization of candida rugosa lipase on superparamagnetic fe3o4 nanoparticles for biocatalysis in low-water media. | a simple immobilization method for candida rugosa lipase on superparamagnetic fe3o4 nanoparticles is described. the fe3o4 nanoparticles were coated with pei and candida rugosa lipase was adsorbed on these particles via electrostatic interactions. the immobilization resulted in marginal simultaneous purification. however, the immobilized preparation showed 110× higher transesterification activity in low-water media. it was also efficient in kinetic resolution of (±)-1-phenylethanol with eep of 99 ... | 2013 | 23934801 |
| survey of mycotic mastitis in dairy cows from heilongjiang province, china. | a survey of the prevalence rate, pathogenic subspecies, and risk factors of mycotic mastitis in dairy cows from heilongjiang province, china, was conducted. milk samples from 412 cows with chronic mastitis were collected and cultured on 8 % sheep blood agar, macconkey agar, and sabouraud agar with chloramphenicol. counting of the morphologically distinct colonies was performed, as well as the isolation and identification of organisms through phenotypical and physiological criteria. four hundred ... | 2013 | 23813119 |
| preparation of new calix[4]arene-immobilized biopolymers for enhancing catalytic properties of candida rugosa lipase by sol-gel encapsulation. | the article describes preparation of new calixarene biopolymers consisting of the immobilization of convenience calixarene derivative onto cellulose and chitosan biopolymers, and the encapsulation of these calixarene biopolymers with candida rugosa lipase within a chemical inert sol-gel supported by polycondensation with tetraethoxysilane and octyltriethoxysilane. the catalytic properties of immobilized lipase were evaluated into model reactions employing the hydrolysis of p-nitrophenylpalmitate ... | 2013 | 23780340 |
| lipases efficiently stearate and cutinases acetylate the surface of arabinoxylan films. | this is the first report on successful enzyme catalyzed surface esterification of hemicellulose films. enzyme catalyzed surface acetylation with vinyl acetate and stearation with vinyl stearate were studied on rye arabinoxylan (ax) films. different surface analytical techniques (ft-ir, tof-sims, esca, ca) show that lipases from mucor javanicus, rhizopus oryzae and candida rugosa successfully surface stearate ax films and that a cutinase from fusarium solani pisi surface acetylates these films. t ... | 2013 | 23774036 |
| the derivation of a chiral substituent code for secondary alcohols and its application to the prediction of enantioselectivity. | a chiral substituent code was proposed based on the features of secondary alcohols, in which a chiral center is attached to two substituents in addition to oh and h substituents. the new chirality code, which was generated by predefining positional information of four substituents attached to stereocenter, was applied to two datasets composed of secondary alcohols as the enantioselective products of asymmetric reactions. in the first dataset, the chemical reaction was catalyzed by a biocatalyst, ... | 2013 | 23666031 |
| synthesis, enantiomer separation, and absolute configuration of 2,6-oxygenated 9-azabicyclo[3.3.1]nonanes. | the synthesis of the enantiomerically pure n-boc 9-azabicyclo[3.3.1]nonane-2,6-dione (4b), a potentially useful chiral building block, from n-bn and n-boc 9-azabicyclo[3.3.1]nonane-2,6-diols 2a and 2b was accomplished. the enantiomer resolution of diols 2a and 2b was achieved by crystallization of their diastereomeric esters or by kinetic resolution of the racemic diol 2a using lipase from candida rugosa (crl). both enantiomers of n-boc protected diol 2b were converted into the corresponding ena ... | 2013 | 23635000 |
| one-pot solvothermal synthesis of highly water-dispersible size-tunable functionalized magnetite nanocrystal clusters for lipase immobilization. | a facile one-pot synthesis of highly water-dispersible size-tunable magnetite (fe3o4) nanocrystal clusters (mncs) end-functionalized with amino or carboxyl groups by a modified solvothermal reduction reaction has been developed. dopamine and 3,4-dihydroxyhydroxycinnamic acid were used for the first time as both a surfactant and interparticle linker in a polylol process for economical and environment-friendly purposes. morphology, chemical composition, and magnetic properties of the prepared part ... | 2013 | 23616374 |
| covalent immobilization of candida rugosa lipase on aldehyde functionalized hydrophobic support and the application for synthesis of oleic acid ester. | this study focuses on candida rugosa lipase (crl) immobilization by covalent attachment on poly(ethylene terephthalate)-grafted glycidyl methacrylate (pet-g-gma) fiber. the immobilization yielded a protein loading of 2.38 mg g(-1) of pet-g-gma fiber. the performances of the immobilized and free crls were evaluated with regard to hydrolysis of olive oil and esterification of oleic acid. the optimum activity ph of the crl was changed by immobilization to neutral range. the maximum activity of the ... | 2013 | 23574345 |
| isolation, identification and growth determination of lactic acid-utilizing yeasts from the ruminal fluid of dairy cattle. | ruminal organic acid production, especially lactic acid, can be modified by feeding cattle highly concentrated diets, which have been shown to adversely affect dairy cattle health. therefore, the use of lactic acid-utilizing organisms is considered to be a potential method for controlling lactic acid levels. this study was conducted to isolate and identify lactic acid-utilizing yeasts from the ruminal fluid of dairy cattle and to determine the specific growth rate and generation time when using ... | 2013 | 23565722 |
| a magnetically separable biocatalyst for resolution of racemic naproxen methyl ester. | candida rugosa lipase (crl) was encapsulated via the sol-gel method, using 5, 11, 17, 23-tetra-tert-butyl-25,27-bis(2-aminopyridine)carbonylmethoxy-26, 28-dihydroxy-calix[4]arene-grafted magnetic fe3o4 nanoparticles (calix-m-e). the catalytic activity of encapsulated lipase (calix-m-e) was tested both in the hydrolysis of p-nitrophenyl palmitate (p-npp) and the enantioselective hydrolysis of racemic naproxen methyl ester. the present study demonstrated that the calixarene-based compound has the ... | 2013 | 23525833 |
| assessment of activities and conformation of lipases treated with sub- and supercritical carbon dioxide. | in order to illustrate the underlining mechanism of the effect of high pressure on lipases from different resources, the influence of compressed carbon dioxide treatment on the esterification activities and conformation of the three lipases candida rugosa lipase (crl), pseudomonas fluorescens lipase, and rhizopus oryzae lipase was investigated in the present work. the results showed that the lipases activities were significantly enhanced in most of high-pressure treatments, except the pressure h ... | 2013 | 23417391 |
| structural and dynamic features of candida rugosa lipase 1 in water, octane, toluene, and ionic liquids bmim-pf6 and bmim-no3. | ionic liquids (ils) and organic chemicals can be used as solvents in biochemical reactions to influence the structural and dynamic features of the enzyme, sometimes detrimentally. in this work we report the results for molecular dynamics simulations of candida rugosa lipase (crl) in ils bmim-pf6 and bmim-no3, as well as organic solvents toluene and octane in an effort to explore the role of solvent on the structure and dynamics of an enzyme known to be active in many nonaqueous media. simulation ... | 2013 | 23387335 |
| extracellular enzyme production and phylogenetic distribution of yeasts in wastewater treatment systems. | the abilities of yeasts to produce different extracellular enzymes and their distribution characteristics were studied in municipal, inosine fermentation, papermaking, antibiotic fermentation, and printing and dyeing wastewater treatment systems. the results indicated that of the 257 yeasts, 16, 14, 55, and 11 produced lipase, protease, manganese dependant peroxidase (mnp), and lignin peroxidase (lip), respectively. they were distributed in 12 identified and four unidentified genera, in which ca ... | 2013 | 23261999 |
| lipase catalyzed ultrasonic synthesis of poly-4-hydroxybutyrate-co-6-hydroxyhexanoate. | four different lipases were compared for ultrasound-mediated synthesis of the biodegradable copolymer poly-4-hydroxybutyrate-co-6-hydroxyhexanoate. the copolymerization was carried out in chloroform. of the enzymes tested, novozym 435 exhibited the highest copolymerization rate, in fact the reaction rate was observed to increase with about 26-fold from 30 to 50°c (7.9×10(-3)ms(-1)), sonic power intensity of 2.6×10(3)wm(-2) and dissipated energy of 130.4jml(-1). copolymerization rates with the ca ... | 2013 | 23231942 |
| comparison of artificial neural network (ann) and response surface methodology (rsm) in optimization of the immobilization conditions for lipase from candida rugosa on amberjet(®) 4200-cl. | candida rugosa lipase (crl) is an important industrial enzyme that is successfully utilized in a variety of hydrolysis and esterification reactions. this work describes the optimization of immobilization conditions (enzyme/support ratio, immobilization temperature, and buffer concentration) of crl on the anionic resin amberjet® 4200-cl, using enantioselectivity (e) as the reference parameter. the model reaction used for this purpose is the acylation of (r,s)-1-phenylethanol. optimal conditions f ... | 2013 | 23215653 |
| preparation of coaxial-electrospun poly[bis(p-methylphenoxy)]phosphazene nanofiber membrane for enzyme immobilization. | a core/sheath nanofiber membrane with poly[bis(p-methylphenoxy)]phospha-zene (pmpph) as the sheath and easily spinnable polyacrylonitrile (pan) as the core was prepared via a coaxial electrospinning process. field-emission scanning electron microscopy and transmission electron microscopy were used to characterize the morphology of the nanofiber membrane. it was found that the concentration of the pan spinning solution and the ratio of the core/sheath solution flow rates played a decisive role in ... | 2012 | 23203055 |
| lipase immobilization on hyper-cross-linked polymer-coated silica for biocatalytic synthesis of phytosterol esters with controllable fatty acid composition. | in this study, a novel mixed-mode composite material, sio(2)@p(maa-co-vbc-co-dvb), was prepared via the hyper-cross-linking of its precursor, which was produced via suspension polymerization in the presence of sio(2) particles. candida rugosa lipase (crl) was immobilized on the sio(2)@p(maa-co-vbc-co-dvb) particles via hydrophobic and weak cation-exchange interaction. the resulting immobilized crl showed much better thermal stability and reusability in comparison to free crl. on the basis of the ... | 2013 | 23199227 |