Candida Antarctica (candida + antarctica)

Distribution by Scientific Domains

Terms modified by Candida Antarctica

  • candida antarctica lipase b

  • Selected Abstracts

    Functionalized Multi-Wall Carbon Nanotubes for Lipase Immobilization,

    I. V. Pavlidis
    Abstract We examine the immobilization of lipase B from Candida antarctica on functionalized multi-wall carbon nanotubes (MWCNTs) through physical adsorption. MWCNTs functionalized with carboxyl-, amine- and ester- terminal groups on their surface are used as immobilization carriers. Dispersion of the nanotubes and the immobilization procedure take place in aqueous and low-water media. High enzyme loadings are attained, up to 25% of the weight of the carbon nanotubes. These novel biomaterials are characterized though FT-IR and Raman spectroscopy. The MWCNT,lipase bioconjugates exhibit high catalytic activity and increased storage and operational stability. The biomaterials retain more than 55% of their initial activity after 6 months at 4,C, while they retain approximately 25% of their initial activity after 30 d of incubation in hexane at 60,C. The catalytic behaviour of the immobilized enzyme depends on the terminal group of the carbon nanotubes, the concentration of the enzyme and the immobilization method employed. [source]

    The lipase/acyltransferase from Candida parapsilosis

    FEBS JOURNAL, Issue 6 2002
    Molecular cloning, characterization of purified recombinant enzymes
    Candida parapsilosis has been previously shown to produce a lipase (i.e. able to catalyze efficiently the hydrolysis of insoluble lipid esters such as triacylglycerols) that preferentially catalyses transfer reactions such as alcoholysis in the presence of suitable nucleophiles other than water, even in aqueous media with high (> 0.9) water thermodynamic activity. The present work describes the cloning and the overexpression of the gene coding for this enzyme. Two ORFs (CpLIP1 and CpLIP2) were isolated. The deduced 465-amino-acid protein sequences contained the consensus motif (G-X-S-X-G) which is conserved among lipolytic enzymes. Only one of the two deduced proteins (CpLIP2) contained peptide sequences obtained from the purified lipase/acyltransferase. Homology investigations showed that CpLIP2 has similarities principally with 11 lipases produced by C. albicans (42,61%) and the lipase A from Candida antarctica (31%) but not with the other lipases sequenced so far. Both CpLIP1 and CpLIP2 were expressed in Saccharomyces cerevisiae, but only CpLIP2 coded for an active protein. The substrate specificity and the catalytic behavior of purified recombinant CpLIP2, with or without a C-terminal histidine tag, were not changed compared to those of the native lipase. [source]

    A Three-Dimensional Quanititative Structure-Activity Relationship (3D-QSAR) Model for Predicting the Enantioselectivity of Candida antarctica Lipase B

    Paolo Braiuca
    Abstract Computational techniques involving molecular modeling coupled with multivariate statistical analysis were used to evaluate and predict quantitatively the enantioselectivity of lipase B from Candida antarctica (CALB). In order to allow the mathematical and statistical processing of the experimental data largely available in the literature (namely enantiomeric ratio E), a novel class of GRID-based molecular descriptors was developed (differential molecular interaction fields or DMIFs). These descriptors proved to be efficient in providing the structural information needed for computing the regression model. Multivariate statistical methods based on PLS (partial least square , projection to latent structures), were used for the analysis of data available from the literature and for the construction of the first three-dimensional quanititative structure-activity relationship (3D-QSAR) model able to predict the enantioselectivity of CALB. Our results indicate that the model is statistically robust and predictive. [source]

    Kinetic Resolution of 1-Biaryl- and 1-(Pyridylphenyl)alkan-1-ols Catalysed by the Lipase B from Candida antarctica

    Robert Kourist
    Abstract Lipase B from Candida antarctica (CAL-B) catalyses the highly enantioselective (E>200) transesterification of some 1-biaryl-2-yl-, -3-yl-, and -4-ylethanols and -propan-1-ols, as well as 1-(o -, m -, and p -pyridylphenyl)ethanols, 6, with vinyl acetate, Kazlauskas' rule being obeyed in all cases. meta and para -Substituted substrates were transformed within several hours (conversion degree ranging from 23,50%), reaction rates for propan-1-ol derivatives being slower than those for ethanol derivatives. Transesterifications of ortho -substituted alcohols took several days and were accompanied by a chemoenzymatic side reaction: the formation of another acetate derived from the hemiacetal between 6 and acetaldehyde coming from vinyl acetate. This side reaction was suppressed in the presence of isopropenyl acetate as acyl donor, conversion degrees for transesterification ranging from 20,40% after ten days (E>200). The usefulness of (R)- 6p as ligand in the asymmetric addition of diethylzinc to benzaldehyde was also demonstrated. [source]

    Lipase-mediated Acidolysis of Fully Hydrogenated Soybean Oil with Conjugated Linoleic Acid

    J. Ortega
    ABSTRACT: Interesterification (acidolysis) of fully hydrogenated soybean oil (melting point = 69.9 C) with conjugated linoleic acid (CLA) was carried out in a batch reactor at 75 C. Lipases from Candida antarctica, Rhizomucor miehei, Pseudomonas sp., and Thermomyces lanuginosus were used at 5% (wt/wt) of the total substrate load. The lipase from Rhizomucor miehei produced the fastest reaction rates, and the greatest extent of incorporation of CLA residues in acylglycerols was achieved in 12 h. Lipases from C. antarctica and T. lanuginosus produced slower initial rates, and maximum extents of incorporation of CLA residues were achieved in 24 h. The lipase from Pseudomonas sp. produced the slowest initial rate. The corresponding maximum extent of incorporation was reached in 48 h. Differential scanning calorimetry analysis of the triacylglycerol (TAG) fractions produced by C. antarctica, R. miehei, and T. lanuginosus lipases after purification by solid phase extraction showed little variation in melting point (60.4 C, 62.8 C, and 60.1 C, respectively). By contrast, the corresponding TAG fraction produced by the Pseudomonas sp. lipase melted at 48.4 C. The positional distribution of the TAGs produced by the lipase from Pseudomonas sp. differed appreciably from those produced by the other enzymes. [source]

    The influence of organic solvent and ionic liquids on the selective formation of 2-(2-ethylhexyl)-3-phenyl-1,2-oxaziridine mediated by lipases,

    Thiago Bergler Bitencourt
    Abstract This paper describes the influence of the addition of ionic liquids (ILs) based on [BMIm][X], where [X],=,SCN, Cl, BF4, and PF6, on the chemo-enzymatic oxidation of N -benzyliden-2-ethylhexylamine to form the corresponding E- and Z -isomers of oxaziridines mediated by Pseudomonas sp. (PSL) and Candida antarctica (CAL-B) lipases in various organic solvents at room temperature (25,C) with urea hydrogen peroxide (UHP). The results showed that the use of different organic solvents in the presence of ILs, critically changes the conversions (5,99%) and the isomeric ratio E:Z, (50,100% E -isomer) of the products formed. Copyright 2010 John Wiley & Sons, Ltd. [source]

    Synthesis and degradation of biomedical materials based on linear and star shaped polyglycidols

    Helmut Keul
    Abstract Linear and star shaped polyglycidols (synonym with polyglycerols) are prepared in a controlled ring opening polymerization of protected glycidols. Beside the molar mass and the polydispersity, the architecture of the polyglycidols is controlled by using mono- and multifunctional mono- and polydispers initiators. Copolymers of dissimilarly protected glycidols as well as copolymers with nonfunctional oxiranes were prepared by means of anionic polymerization while copolymers of protected glycidol with tetrahydrofuran were prepared by means of cationic polymerization. Polyethers with functional groups in the side chains (functional polyethers) with special emphasis on polyglycidols (containing hydroxymethyl groups in the side chains) were used to prepare multifunctional polymers and (hetero)grafted polymer brushes via chemical and enzyme catalyzed reaction. The potential of poly(glycidol- graft -,-caprolactone)- co -glycidol) prepared via enzyme catalyzed grafting of polyglycidols using ,-caprolactone as a monomer and Lipase B from Candida antarctica as a catalyst is presented. Finally, comparative degradation studies of densely and loosely grafted polyglycidols are presented and discussed. 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3209,3231, 2009 [source]

    Lipase-Catalyzed Synthesis and Properties of Poly[(12-hydroxydodecanoate)- co -(12-hydroxystearate)] Directed towards Novel Green and Sustainable Elastomers

    Hiroki Ebata
    Abstract Novel green and sustainable elastomers having both good biodegradability and chemical recyclability properties were designed and synthesized using potentially biobased materials and lipase as an environmentally benign catalyst. High molecular weight poly[(12-hydroxydodecanoate)- co -(12-hydroxystearate)] [poly(12HD- co -12HS)] samples with varying monomer ratios were prepared by the polycondensation of 12-hydroxydodecanoic acid and methyl 12-hydroxystearate using immobilized lipase from Candida antarctica (IM-CA) in toluene in the presence of molecular sieves 4A at 90,C. Although poly(12HD) is a highly crystalline polyester having a melting temperature (Tm) of 87.6,C and crystalline temperature (Tc) of 64,C, by the copolymerization of 12HD with 12HS, both the Tm and Tc of the copolymer decreased with increasing 12HS contents, and poly(12HD- co -12HS) containing more than 60 mol-% 12HS was a viscous liquid at room temperature. At the same time, the Young's modulus and hardness also decreased with increasing 12HS content, and poly(12HD- co -36 mol-% 12HS) exhibited an elastic behavior, having a hardness of 70 A using a durometer A. In addition, it showed an excellent biodegradability by activated sludge and chemical recyclability by lipase. [source]

    In this issue: Biotechnology Journal 8/2010

    Article first published online: 12 AUG 2010
    Biocatalyst microemulsions Pavlidis et al., Biotechnol. J. 2010, 5, 805,812 Enzymes maintain their catalytic activity when hosted in aqueous nanodroplets like reverse micelles. Researchers from Ioannina, Greece, propose the use of water-in-ionic liquid microemulsionbased organogels (w/IL MBGs) as novel supports for the immobilization of lipase B from Candida antarctica and lipase from Chromobacterium viscosum. These novel lipase-containing w/IL MBGs can be effectively used as solid phase biocatalysts in various polar and non-polar organic solvents or ILs, exhibiting up to 4.4-fold higher esterification activity compared to water-in-oil microemulsion-based organogels. The immobilized lipases retain their activity for several hours at 70C, while their half life time is up to 25-fold higher compared to that observed in w/IL microemulsions Biocatalyst cryogelation Bieler et al., Biotechnol. J. 2010, 5, 881,885 Entrapment of biocatalysts in hydrogel beads allows stable operation in otherwise deteriorating solvents. Doing this by cryogelation is a gentle method to extend the scope of biocatalysis. To foster the use of this versatile method, researchers from Aachen, Germany, devised an automated injector for the production of PVA/PEG-enzyme immobilisates. The device consists of a thermostated reservoir connected to a programmable injector nozzle and an agitated receiving bath for the droplets. This lab-scale production unit yields up to 1500 beads with immobilized enzyme per minute with a narrow size distribution and good roundness. Biocatalyst membrane reactor Lyagin et al., Biotechnol. J. 2010, 5, 813,821 Screening of biocatalysts, substrates or conditions in the early stages of bioprocess development requires an enormous number of experiments and is a tedious, expensive and time-consuming task. Currently available screening systems can only be operated in batch or fed-batch mode, which can lead to severe misinterpretations of screening results. Researchers from Berlin, Germany, now developed a novel screening system that enables continuous feeding of substrates and continuous removal of products. A prototype based on the membrane reactor concept was designed and operated for a model reaction, the hydrolysis of cellulose. [source]

    Water-in-ionic liquid microemulsion-based organogels as novel matrices for enzyme immobilization

    Ioannis V. Pavlidis
    Abstract The use of water-in-ionic liquid microemulsion-based organogels (w/IL MBGs) as novel supports for the immobilization of lipase B from Candida antarctica and lipase from Chromobacterium viscosum was investigated. These novel lipase-containing w/IL MBGs can be effectively used as solid phase biocatalysts in various polar and non-polar organic solvents or ILs, exhibiting up to 4.4-fold higher esterification activity compared to water-in-oil microemulsion-based organogels. The immobilized lipases retain their activity for several hours at 70C, while their half life time is up to 25-fold higher compared to that observed in w/IL microemulsions. Fourier-transform infrared spectroscopy data indicate that immobilized lipases adopt a more rigid structure, referring to the structure in aqueous solution, which is in correlation with their enhanced catalytic behavior observed. [source]

    Expression of functional Candida antarctica lipase B in a cell-free protein synthesis system derived from Escherichia coli

    Chang-Gil Park
    Abstract This article reports the cell-free expression of functional Lipase B from Candida antarctica (CalB) in an Escherichia coli extract. Although most of the cell-free synthesized CalB was insoluble under conventional reaction conditions, the combined use of molecular chaperones led to the soluble expression of CalB. In addition, the functional enzyme was generated by applying the optimal redox potential. When examined using p -nitrophenyl palmitate as a substrate, the specific activity of the cell-free synthesized CalB was higher than that of the reference protein produced in Pichia pastoris. These results highlight the potential of cell-free protein synthesis technology as a powerful platform for the rapid expression, screening and analysis of industrially important enzymes. 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009 [source]

    Chemoenzymatic synthesis and properties of Schiff bases containing (R)-1-(9-anthryl)ethylamine

    CHIRALITY, Issue 8 2002
    Marin Roje
    Abstract Racemic 1-(9-anthryl)ethylamine (10), obtained in 70% overall yield from commercial 9-cyanoanthracene, was kinetically resolved by the Candida antarctica A lipase-catalyzed acetylation with isopropyl acetate as acyl donor, affording (R)-(+)- 10 with 95.8% enantiomeric excess (e.e.) (E- value 43.5), which afforded Schiff bases (R)- 4 and(R)- 8.1H-NMR, CD, and MM2 calculations offer a consistent picture of the conformational properties of these potential ligands and an explanation for the limited enhancement of enantioselectivity in cyclopropanation of styrene by their Cu(I) complexes, as compared with previously studied ligands in this series. Chirality 14:625,631, 2002. 2002 Wiley-Liss, Inc. [source]