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1.
微乳液和微乳液凝胶中脂肪酶催化的酯合成反应 总被引:7,自引:0,他引:7
在ACT/异辛烷/水形成的油包水微乳液中,研究了Candidalipolytical(CL)脂肪酶催化庚酸和庚醇的酯化反应,动力学研究表明反应符合乒乓(Ping-Pong)BiBi机制,两底物酸和醇均有抑制效应,并测定了反应的表观动力学常数,将CL脂肪酶固定于含明胶的微乳液凝胶(MBGs)中,可制得固定化脂肪酶,含酶的MBGs在非极性有机溶剂中可作为一种新的固相催化剂,并研究了MBGs在异辛烷中催化合成酯反应的性能,所制得的MBGs重复利用性和贮存稳定性都非常好。 相似文献
2.
微乳液中脂肪酶和含明胶的微乳液凝胶中固定化脂肪酶的催化特性 总被引:1,自引:0,他引:1
在双2-乙基己基琥珀酸酯磺酸钠(AOT)油包水微乳液中Calytical脂肪酶催化月桂酸和戊醇的酯化反应动力学研究表明,反应符合乒乓(BiBi)机制.表观速率常数km酸=0.13518mol/L,km醇=0.22423mol/L,最大反应速度vmax=1.3873×10-5mol/(L·min·mg).将该脂肪酶固定于含明胶的微乳液凝胶(MBGs)中,制得固定化脂肪酶,含酶MBGs在非极性溶剂中可作为固相催化剂,并研究了其在辛烷中催化酯化的性能.所制得的含酶MBGs物理稳定性好,重复利用10次以上,其转化率仍达初始转化率的90%. 相似文献
3.
Soares Cleide M. F. De Castro Heizir F. Santana M. Helena A. Zanin Gisella M. 《Applied biochemistry and biotechnology》2002,98(1-9):863-874
In agreement with previous studies, promising results were obtained when lipase was immobilized on controlled pore silica
(CPS) in the presence of polyethylene glycol (PEG 1500). This methodology rendered immobilized derivatives with higher operational
stability than those lacking PEG 1500. This article extends the scope of this approach by evaluating the combined effects
of PEG concentration and lipase loading employing a multivariate statistical approach. A 22 factorial design with center point was adopted for a full understanding of these effects and their interactions. Conditions
that maximize the immobilization yield were different from those attained for the biocatalyst’s operational stability. Possible
reasons for the increase in both activity and stability of lipase immobilized on CPS in the presence of PEG 1500 are discussed
in light of the influence of surface hydrophilic/hydrophobic balance. 相似文献
4.
采用界面活化的溶胶凝胶包埋Candida rugosa脂肪酶(CRL)催化合成了维生素E琥珀酸酯.考察了影响溶胶凝胶包埋固定化CRL的因素,获得的最佳固定化条件为:丙基三甲氧基硅烷/正硅酸四乙酯摩尔比为1/1,水与硅烷前体摩尔比为15,酶的添加量为0.5mg/ml,PEG400的添加量为12μl/ml溶胶. 溶胶凝胶包埋的CRL在50℃,18h后其活性仍然保持了70.58%,是游离酶的2.6倍,且稳定性得到了明显的改善.基于CRL的界面特性,采用五种表面活性剂对其进行界面活化.结果表明,采用橄榄油活化的溶胶凝胶包埋的CRL合成维生素E琥珀酸酯的酯化活力最高,相比原酶和未界面活化的溶胶凝胶包埋酶分别提高了6.7和1.43倍. 相似文献
5.
Ranyere L. Souza Emanuelle L. P. Faria Renan T. Figueiredo Alini T. Fricks Gisella M. Zanin Onélia A. A. Santos Álvaro S. Lima Cleide M. F. Soares 《Journal of Thermal Analysis and Calorimetry》2014,117(1):301-306
Lipases from Burkholderia cepacia were encapsulated using polyethylene glycol (PEG, M w 1500) at various concentrations (0.5–3.0 %, w/v) as an additive during the sol–gel immobilisation process. Matrixes immobilized in the presence and absences of additives were characterized by thermal analysis [thermogravimetric (TG) and differential scanning calorimetry (DSC)], scanning electron microscopy (SEM), enzymatic activity, and total activity recovery yield (Ya). The addition of PEG increased the activity values, with Ya just above 1.0 % (w/v) in the presence of PEG. The additional of 1.0 % (w/v) PEG increased enzyme activity from 33.98 to 89.91 U g?1 and the values of recovery yield were 43.0–91.4 %, compared to values of the samples without PEG. PEG enhanced the thermal stability of the matrix structure in the temperature range 50–200 °C, as confirmed by TG and DSC analyses. This was influenced by the presence of water bound to the matrix. The SEM micrographs clearly showed an increase in the number of deposits on the material surface, producing matrices with greater porosity. 相似文献
6.
Dawei Chen Cheng Peng Houjin Zhang Yunjun Yan 《Applied biochemistry and biotechnology》2013,169(7):2189-2201
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 had a negative effect on CRL activity in supercritical condition. Mild depressurization rate could remain the lipase’s activity by protecting its rigid structure under supercritical fluid. Conformational analysis by Fourier transform-infrared spectrometry and fluorescence emission spectra revealed that the variances of lipase activity after high-pressure treatment were correlated with the changes of its α-helix content and fluorescence intensity. Additionally, transesterification catalyzed by three lipases in supercritical carbon dioxide were conducted, and 87.2 % biodiesel conversion was obtained by CRL after 3 h, resulting in a great reduction of reaction time. 相似文献
7.
Soares Cleide M. F. De Castro Heizir F. Santana M. Hellena A. Zanin Gisella M. 《Applied biochemistry and biotechnology》2001,91(1-9):703-718
Candida rugosa lipase was covalently immobilized on silanized controlled poresilica (CPS) previously activated with glutaraldehyde in the
presence of several additives to improve the performance of the immobilized from in long-term operation. Proteins (albumin
and lecithin) and organic molecules (β-cyclodextrin and polyethylene glycol [PEG]-1500) were added during the immobilization
procedure, and their effects are reported and compared to the behavior of the immobilized biocatalyst in the absence (lacking)
of additive. The selection of the most efficient additive at different lipase loadings (150–450 U/g of dry support) was performed
by experimental design. Two 22full factorial designs with two repetitions at the center point were employed to evaluate the immobilization yield. A better,
stabilizing effect was found when small amounts of albumin or PEG-1500, were added simul-taneou sly to the lipase on to the
support. The catalytic activity had a maximum (193 U/mg) for lipase loading of 150 U/g of dry support using PEG-1500 as the
stabilizing additive. This immobilized system was used to perform esterification reactions under repeated batch cycles (for
the synthesis of butyl butyrate as a model). The half-life of the lipase immobilized on CPS in the presence of PEG-150 was
found to increase fivefold compared with the control (immobilized lipase on CPS without additive). 相似文献
8.
9.
Fatih Ozcan Ozlem Sahin Mustafa Yilmaz 《Journal of inclusion phenomena and macrocyclic chemistry》2009,63(1-2):123-129
This article describes the synthesis of a new calix[4]arene 1,3-distal glutaraldehyde derivative 4 as a cross-linker-reagent for immobilization of Candida rugosa lipase (CRL). p-tert-Butylcalix[4]arene 1,3-distal diaminoalkyl derivative (3) synthesized via aminolysis reaction of 5,11,17,23-tert-butyl-25,27-ethoxycarbonylmethoxy-26,28-hydroxycalix[4]arene (2) with 1,8-diaminooctane. Compound 3 was converted to its aldehyde derivative (4) by the treatment with glutaraldehyde solution. 4 was used in lipase immobilization in order to see the role of calix[4]arene binding site on the lipase activity and stability. It was observed that the immobilized lipase activity was maintained at levels exceeding 95% of its original activity after 40 min. 相似文献
10.
Hai Nam Hoang Yoshihiro Nagashima Shuichi Mori Hiroyuki Kagechika Tomoko Matsuda 《Tetrahedron》2017,73(20):2984-2989
For the first time, CO2-expanded bio-based liquids were reported as novel and sustainable solvents for biocatalysis. Herein, it was found that by expansion with CO2, 2-methyltetrahydrofuran (MeTHF), and other bio-based liquids, which were not favorable solvents for immobilized Candida antarctica lipase B (Novozym 435) catalyzed transesterification, were tuned into excellent reaction media. Especially, for the kinetic resolution of challenging bulky secondary substrates such as rac-1-adamantylethanol, the lipase displayed very high activity with excellent enantioselectivity (E value > 200) in CO2-expanded MeTHF (MeTHF concentration 10% v/v, 6 MPa), whereas there was almost no activity observed in conventional organic solvents. 相似文献
11.
12.
Yukio Nagasaki Kenji Yoshinaga Koshiro Kurokawa Michihiro Iijima 《Colloid and polymer science》2007,285(5):563-567
Gold colloid possessing both lipase and PEG-tethered chains on the surface was prepared by the adsorption of lipase, followed
by the immobilization of the PEG/polycation block copolymer on the colloid surface. The obtained colloid showed high dispersion
stability up to 0.3 M NaCl concentration. The enzymatic activity of the lipase on the colloid complex was equivalent to the
native enzyme. Surprisingly, more than 95% of the initial enzymatic activity was retained after repeated thermal treatments
(five times) at 58 °C for 10 min. The PEG condensed layer between the immobilized enzyme on the gold colloid may prevent the
denaturation of the enzyme at high temperature.
Electronic supplementary material Supplementary material is available in the online version of this article at and is accessible for authorized users. 相似文献
13.
Lisa Tanzi Marina Simona Robescu Sara Marzatico Teresa Recca Yongmin Zhang Marco Terreni Teodora Bavaro 《Molecules (Basel, Switzerland)》2020,25(23)
Regioselective deprotection of acetylated mannose-based mono- and disaccharides differently functionalized in anomeric position was achieved by enzymatic hydrolysis. Candida rugosa lipase (CRL) and Bacillus pumilus acetyl xylan esterase (AXE) were immobilized on octyl-Sepharose and glyoxyl-agarose, respectively. The regioselectivity of the biocatalysts was affected by the sugar structure and functionalization in anomeric position. Generally, CRL was able to catalyze regioselective deprotection of acetylated monosaccharides in C6 position. When acetylated disaccharides were used as substrates, AXE exhibited a marked preference for the C2, or C6 position when C2 was involved in the glycosidic bond. By selecting the best enzyme for each substrate in terms of activity and regioselectivity, we prepared a small library of differently monohydroxylated building blocks that could be used as intermediates for the synthesis of mannosylated glycoconjugate vaccines targeting mannose receptors of antigen presenting cells. 相似文献
14.
Gloria Fernandez-LorenteJose M Palomo Jany CoccaCesar Mateo Paola MoroMarco Terreni Roberto Fernandez-Lafuente Jose M Guisan 《Tetrahedron》2003,59(30):5705-5711
Purified lipases (via interfacial activation on hydrophobic supports) from different microbial extracts have been evaluated in the regio-selective hydrolysis of peracetylated sugars (peracetylated glucose, ribose and sucrose). Among the enzymes tested, lipases from Candida rugosa (CRL) and from Pseudomonas fluorescens (PFL) exhibited the best properties in these reactions.Then, we have prepared two different immobilized lipase preparations obtained by interfacial activation on hydrophobic supports or by covalent attachment on glutaraldehyde agarose. Interfacially activated lipases exhibited a higher activity than covalently attached enzymes (even by a 100-fold factor), giving the higher yields of mono deacetylated sugars (in some instances by more than a threefold factor) in short reaction times. In the hydrolysis of 1,2,3,5-tetra-O-acetyl-β-d-ribofuranose catalyzed by PFL adsorbed on octyl agarosa, hydrolyzed mainly the 3 position (30% of yield) while the CRL gave the hydrolysis only in position 5 (about 50% of yield).Depending on the enzyme immobilized preparation, we have been able also to obtain selective hydrolysis of 1,2,3,4,6-penta-O-acetyl-α/β-d-glucopyranose obtaining a free hydroxyl group in position 1, 4 or 6. Moreover, selective hydrolysis in the 4′ position of peracetylated sucrose was achieved when the hydrolysis is performed with CRL immobilized on octyl-agarose (yield was 77%). 相似文献
15.
In the present study, insoluble yeast beta-glucan (IYG) has been explored as a support matrix for enzyme immobilization. IYG contains mainly beta-(1-3) linkages along with some intra- or inter-molecular branches of beta-(1-6) linkages with large number of free hydroxyl groups. Epichlorohydrin was used to convert these free hydroxyl groups into activated epoxy groups that are capable of forming covalent linkages with various groups of enzyme molecule. The epoxy-activated IYG was evaluated for immobilization of Candida rugosa lipase (CRL). Post-immobilization treatment of 5% glutaraldehyde was given in order to achieve stable and irreversible binding of enzyme on the support. The resultant biocatalytic IYG support expressed lipase activity of 8136.7 U/g and 59.6% activity yield. There was 51.05% retention of synthetic activity after six repeated esterification cycles, indicating its stability and reusability in non-aqueous medium. Moreover, the immobilized lipase gave the storage half-life of about 285 days (at 4 degrees C). 相似文献
16.
Farshad Darvishi Jacqueline Destain Iraj Nahvi Philippe Thonart Hamid Zarkesh-Esfahani 《Applied biochemistry and biotechnology》2012,168(5):1101-1107
The extracellular lipase of Yarrowia lipolytica presents numerous potentialities for biotechnological applications. This work describes the development and storage of powders obtained from supernatants containing Y. lipolytica lipase by freeze-drying as downstream process that is important in obtaining a stable lipase powder with high enzymatic activity. Lipase was produced by Y. lipolytica U6 mutant strain in 20-L bioreactor. Non-concentrated cell-free culture supernatant samples were supplemented with different concentrations (0.5?C1?%) of maltodextrin and glycerol as additives to freeze-drying. Effects of additives, temperature, pH, and storage time on lipase powders were determined. After addition of additives, freeze-drying yield increased 3.5-fold compared to supernatant without additive. Maltodextrin with 0.5?% concentration gave the best protection of lipase during dehydration treatment and its freeze-drying yield (77?%) is better than other formulations. Lipase powders were stored at 4 and 25?°C for 46?weeks without loss of lipase activity. A common impediment to the production of commercial enzyme is their low-stability aqueous solutions. The present study shows that freeze-dried lipase powders of Y. lipolytica have good stability for storage and various applications. 相似文献
17.
Alberta N. A. Aryee Benjamin K. Simpson 《Applied biochemistry and biotechnology》2012,168(8):2105-2122
Grey mullet (Mugil cephalus) lipase was isolated using para-aminobenzamidine agarose and immobilized on octyl Sepharose CL-4B (o-Sep). Immobilized grey mullet lipase (GMLi) had a 10?°C higher optimum temperature compared to the free enzyme and showed remarkable thermal stability. GMLi was most active within the pH range of 8.0?C9.5 with an optimum at 8.5. Immobilization also enhanced the storage stability and reusability of the enzyme with minimal changes in efficiency during repeated batches. GMLi showed variable stabilities in various organic solvents. A signal in the amide I absorption region of the FTIR spectrum of GMLi was attributed to the protein layer on o-Sep. The surface morphology of o-Sep was visualized on a Zeiss stereomicroscope as globular-shaped beads. 相似文献
18.
Mnica Ruiz Esteban Plata John J. Castillo Claudia C. Ortiz Gina Lpez Sandra Baena Rodrigo Torres Roberto Fernandez-Lafuente 《Molecules (Basel, Switzerland)》2021,26(6)
In this work, the effect of different immobilization procedures on the properties of a lipase obtained from the extremophilic microorganism Serratia sp. USBA-GBX-513, which was isolated from Paramo soils of Los Nevados National Natural Park (Colombia), is reported. Different Shepharose beads were used: octyl-(OC), octyl-glyoxyl-(OC-GLX), cyanogen bromide (BrCN)-, and Q-Sepharose. The performance of the different immobilized extremophile lipase from Serratia (ESL) was compared with that of the lipase B from Candida antarctica (CALB). In all immobilization tests, hyperactivation of ESL was observed. The highest hyperactivation (10.3) was obtained by immobilization on the OC support. Subsequently, the thermal stability at pH 5, 7, and 9 and the stability in the presence of 50% (v/v) acetonitrile, 50% dioxane, and 50% tetrahydrofuran solvents at pH 7 and 40 °C were evaluated. ESL immobilized on octyl-Sepharose was the most stable biocatalyst at 90 °C and pH 9, while the most stable preparation at pH 5 was ESL immobilized on OC-GLX-Sepharose supports. Finally, in the presence of 50% (v/v) tetrahydrofuran (THF) or dioxane at 40 °C, ESL immobilized on OC-Sepharose was the most stable biocatalyst, while the immobilized preparation of ESL on Q-Sepharose was the most stable one in 40% (v/v) acetonitrile. 相似文献
19.
Bin Zhao Xinlong Liu Yanjun Jiang Liya Zhou Ying He Jing Gao 《Applied biochemistry and biotechnology》2014,173(7):1802-1814
Lipase Candida sp. 99–125 has been proved to be quite effective in catalyzing organic synthesis reactions and is much cheaper than commercial lipases. Mesoporous silicates are attractive materials for the immobilization of enzymes due to their unique structures. The present research designed a hydrophobic silicate with uniform pore size suitable for the comfort of lipase Candida sp. 99–125 for improving its activity and stability. The resulting immobilized lipase (LP@PMO) by adsorption was employed to catalyze hydrolysis, esterification, and transesterification reactions, and the performances were compared with the lipase immobilized on hydrophilic silicate (LP@PMS) and native lipase. The LP@PMO showed as high activity as that of native lipase in hydrolysis and much increased catalytic activity and reusability in the reactions for biodiesel production. Besides, LP@PMO also possessed better organic stability. Such results demonstrate that immobilization of lipase onto hydrophobic supports is a promising strategy to fabricate highly active and stable biocatalysts for applications. 相似文献
20.
Cleide M. F. Soares Heizir F. De Castro Flávio F. De Moraes Gisella M. Zanin 《Applied biochemistry and biotechnology》1999,79(1-3):745-757
Candida rugosa lipase was immobilized by covalent binding on controlled poresilica (CPS) using glutaraldehyde ascross-linking agent under aqueous and nonaqueous conditions. The immobilized C. rugosa was more active when the coupling procedure was performed in the presence of a nonpolar solvent, hexane. Similar optima pH (7.5–8.0) was found for both free and immobilized lipase. The optimum temperature for the immobilized lipase was about 10°C higher than that for the free lipase. The thermal stability of the CPS lipase was alsogreater than the original lipase preparation. Studies on the operational stability of CPS lipase revealed good potential for recycling under aqueous (olive-oil hydrolysis) and nonaqueous (butyl butyrate synthesis) conditions. 相似文献