High Stability In Organic Solvents Research Articles

Structure and Properties of a Mixed-Ligand Co-MOF That Was Synthesized in Situ from a Single Imidazole–Pyridyl–Tetrazole Trifunctional Ligand

A mixed-ligand Co-MOF (SCNU-Z7) based on a new imidazole–pyridyl–tetrazole trifunctional ligand, 3-(imidazol-1-yl)-5-(tetrazol-5-yl) pyridine (HITP), was constructed using a solvothermal reaction. Single-crystal X-ray diffraction analysis revealed that in addition to HITP, the 5,5′-bis-(2H-tetrazol-5-yl)-[3,3′]bipyridinyl (H2BTBP) ligand obtained by the in situ reaction of HITP is also incorporated into the framework, thus generating a mixed-ligand metal–organic framework (MOF). SCNU-Z7 has a 3D porous framework with 1D channels along the c axis based on tetranuclear secondary building blocks and has a new highly (3,4,10)-connected network topology with the symbol (416·620·89)(43)2(44·62). SCNU-Z7 exhibits high stability in organic solvents but instability in water. Gas adsorption studies indicated that SCNU-Z7 can absorb CO2 more than N2. Magnetic studies indicate the existence of dominant antiferromagnetic interactions between Co(II) atoms. Due to porosity, Co(II) ions, nitrogen-rich conjugated aromatic rings, and uncoordinated nitrogen atoms in its framework, SCNU-Z7 can capture iodine in vapor with a capacity of 2.7 g/g. The strong interactions between the framework and the iodine molecules cause the amorphization of the framework, and approximately 60% of the adsorbed iodine molecules can be stably stored in the framework. This study provides a new possible route for obtaining mixed-ligand MOFs and provides a new example for stably capturing iodine in MOFs via amorphization.

Metal-organic framework based on iron and terephthalic acid as a multiporous support for lipase Burkholderia lata LBBIO-BL02 and its potential for biocatalysis

Metal-organic frameworks (MOFs) are versatile materials because they have a large internal surface area and tuneable pores, making them suitable for enzyme immobilization. In this study, we prepared a typical microporous Fe-BDC MOF through a thermal treatment to produce additional meso and macropores interconnected to each other, capable of immobilizing the Burkholderia lata LBBIO-BL02 (BLL) lipase by entrapment and physical adsorption. The immobilization efficiency (E) was 90%, and the activity retention (R) was 400% (pNPP hydrolysis). The immobilized lipase (BLL@BDC) also showed excellent activity in the hydrolysis of vegetable oils in aqueous medium, achieving up to 3,200 U g−1 for olive oil, as well as high stability in organic solvents, especially for polar ones, such as iso-propanol (101.5 ± 2.6%), ethanol (103.0 ± 6.0%) and acetone (107.7 ± 8.3%). The results indicate that the multiporous Fe-BDC MOF is a promising support for lipase immobilization and further application in biocatalysis performed in organic media.

Whole cell biosynthesis of luteolin glycosides by engineered Corynebacterium glutamicum harboring the amylosucrase gene

The transglycosylation activity of Deinococcus geothermalis amylosucrase (DgAS) expressed in Corynebacterium glutamicum (cDgAS) was optimized for luteolin glycoside synthesis using purified enzymes (PEs), whole cells (WCs) suspended in buffer (WCB) and WCs in ethanol (WCE). Unlike PE, both WCB and WCE had high transglycosylation yields exceeding 95% over a wide temperature range, with cells in ethanol exhibiting the greatest enzymatic activity for up to 48 h due to membrane degradation and the slow release of cDgAS, which led to lysis and death. Meanwhile, in buffer, protection of the cytoplasmic membrane and ideal pH conditions maintained activity for over 200 h. To improve their performance, WCs were immobilized on agarose and the resulting immobilized cells (ICs) had high stability in organic solvents, although WCB possessed greater thermal stability at 50 °C. The reaction parameters for PE, WCE, WCB, and IC transglycosylation were optimized using response surface methodology, and ICs required lower concentrations of substrates while synthesizing higher concentrations of reaction products in addition to producing the novel compound luteolin maltotrioside after several cycles of reuse. This study expanded on the range of possibilities for the industrial application of C. glutamicum in increasing the production and bioavailability of novel and improved products.

Spray-coated graphene oxide hollow fibers for nanofiltration

Advances in process intensification in the chemical and pharmaceutical industry depends on the availability of more sustainable separation methods. For this progress, membranes with high stability in organic solvents are needed. GO-coated membranes could be advantageous in these applications, being chemically, thermally and mechanically stable. However, simple, scalable, low-cost fabrication methods, particularly for GO deposition on hollow fibers are still in an early phase. We propose here a simple spray-coating method for deposition of GO sheets on crosslinked hollow fiber supports. We first fabricated polyetherimide hollow fiber membranes and crosslinked them with hexamethylene diamine. These supports have strong tolerance to various organic solvents. The amide reaction arising between the imide groups of polyetherimide and the amine groups of hexamethylene diamine provide even higher chemical and mechanical stability. Thereafter, the spray-coating of GO dispersions led to the formation of a stable selective layer on the hollow fibers. An excellent adhesion between GO and the substrate was achieved. The chemical reasons for that were investigated by solid state NMR. Overall, this simple method enables the application of GO hollow fiber membranes in organic solvent nanofiltration, with high performance demonstrated in water and acetone.

Preparation of PEEK Membranes with Excellent Stability Using Common Organic Solvents

Poly(ether ether ketone) (PEEK) is one of the most attractive polymers for organic solvent resistance applications because of its high thermal and organic solvent resistance. However, one of the main disadvantages is that PEEK has to be processed by using harsh solvents, such as methanesulfonic and sulfuric acid. Here, we report for the first time the preparation of PEEK membranes for organic solvent filtration by using common organic solvents. The preparation method consists of the conversion of PEEK into a soluble precursor, followed by dissolution in a mixture of tetrahydrofuran and N,N-dimethylacetamide. The resulting solution is used to obtain the membranes by phase inversion. In the second step, we convert the PEEK precursor to PEEK by treating the obtained membranes with an aqueous acid solution. The resulting PEEK membranes have good permeance and rejection, along with high stability in organic solvents and at high temperatures (up to 140 °C). This procedure opens many possibilities for processing PEEK into membranes by using common techniques to obtain flat sheet membranes or hollow fibers for a broad range of applications.

Two Manganese Peroxidases and a Laccase of Trametes polyzona KU-RNW027 with Novel Properties for Dye and Pharmaceutical Product Degradation in Redox Mediator-Free System

Two manganese peroxidases (MnPs), MnP1 and MnP2, and a laccase, Lac1, were purified from Trametes polyzona KU-RNW027. Both MnPs showed high stability in organic solvents which triggered their activities. Metal ions activated both MnPs at certain concentrations. The two MnPs and Lac1, played important roles in dye degradation and pharmaceutical products deactivation in a redox mediator-free system. They completely degraded Remazol brilliant blue (25 mg/L) in 10–30 min and showed high degradation activities to Remazol navy blue and Remazol brilliant yellow, while Lac1 could remove 75% of Remazol red. These three purified enzymes effectively deactivated tetracycline, doxycycline, amoxicillin, and ciprofloxacin. Optimal reaction conditions were 50 °C and pH 4.5. The two MnPs were activated by organic solvents and metal ions, indicating the efficacy of using T. polyzona KU-RNW027 for bioremediation of aromatic compounds in environments polluted with organic solvents and metal ions with no need for redox mediator supplements.

Cloning, expression and characterization of the esterase estUT1 from Ureibacillus thermosphaericus which belongs to a new lipase family XVIII.

A new esterase gene from thermophilic bacteria Ureibacillus thermosphaericus was cloned into the pET32b vector and expressed in Escherichia coli BL21(DE3). Alignment of the estUT1 amino acid sequence revealed the presence of a novel canonical pentapeptide (GVSLG) and 41-47% identity to the closest family of the bacterial lipases XIII. Thus the esterase estUT1 from U. thermosphaericus was assigned as a member of the novel family XVIII. It also showed a strong activity toward short-chain esters (C2-C8), with the highest activity for C2. When p-nitrophenyl butyrate is used as a substrate, the temperature and pH optimum of the enzyme were 70-80°C and 8.0, respectively. EstUT1 showed high thermostability and 68.9±2.5% residual activity after incubation at 70°C for 6h. Homology modeling of the enzyme structure showed the presence of a putative catalytic triad Ser93, Asp192, and His222. The activity of estUT1 was inhibited by PMSF, suggesting that the serine residue is involved in the catalytic activity of the enzyme. The purified enzyme exhibited high stability in organic solvents. EstUT1 retained 85.8±2.4% residual activity in 30% methanol at 50°C for 6h. Stability at high temperature and tolerance to organic solvents make estUT1 a promising enzyme for biotechnology application.

Identification and Characterization of a Novel Thermophilic, Organic Solvent Stable Lipase of Bacillus from a Hot Spring.

A novel lipase gene lip256 was cloned and identified from the genomic library of hot spring strain Bacillus sp. HT19. The deduced amino acid sequence of lip256 has less than 32% identity to a predicted esterase (Cog1752) from Photobacterium leiognathi lrivu.4.1 and contains a novel motif (GTSAG) that differs from other clusters in the lipase superfamily. Following purification, a single band was obtained with a molecular mass of 33kDa by SDS-PAGE, and the optimal temperature and pH for lipolytic activity of Lip25 were 70°C and 9.0, respectively. Lip256 exhibited high activity at high temperatures, with 40% maximum activity at 80°C and good stability at temperatures ranges between 50 and 80°C. Additionally, the enzyme was highly stable in the presence of butyl-alcohol, glycerol, acetonitrile, pyridine, and urea. However, the presence of acetone, methanol, trichloromethane, petroleum ether, hexane, tert-butanol, isopropanol, dithiothreitol, ethylenediaminetetraacetic acid, polyhexamethylene biguanide, dimethyl sulfoxide, benzene, Triton X-100, Tween-20, Tween-80, and sodium dodecyl sulfate suppressed or absolutely inhibited enzyme activity. Furthermore, Ca2+, Mg2+, and Cu2+ suppressed enzyme activity, whereas Na+, Fe3+, K+, Fe2+, and Sr2+ enhanced enzyme activity. The unique characteristics of novel lipase Lip256, including its thermo-alkaliphilic performance, high tolerance toward metal ions, inhibitors, and detergents, and high stability in organic solvents, implied that this enzyme might be an interesting candidate for industrial processes.

Development of a positively charged nanofiltration membrane for use in organic solvents

In this work, a positively charged nanofiltration membrane was developed by chemical modification of a P84 copolyimide ultrafiltration membrane using branched polyethylenimine. The effect of reaction temperature on membrane morphology, surface charge, and separation performance was investigated. A reaction temperature of 70°C was optimal as the membrane showed best performance in terms of salt rejections and water fluxes when Na2SO4, NaCl and CaCl2 aqueous solutions were used as feeds. Such membrane had a molecular weight cut off (MWCO) of 226Da indicating its effectiveness for separation of organics. Rejections to three dyes in methanol solutions were in the order of methyl orange (negative, MW: 327Da)<disperse red (neutral, MW: 314Da)<safranine O (positive, MW: 351Da). The results suggest that the positive charge on membrane surface induce higher rejection to positive organic molecules due to the charge repulsion effect. Additionally, the membrane had very high stability in organic solvents; no significant changes in membrane performance and membrane structure were observed after being immersed in dimethyl formamide (DMF) for 1 month.

Construction of controllable size silver nanoparticles immobilized on nanofibers of chitin microspheres via green pathway

In the present work, nanofibrous chitin microsphere (NCM) was prepared via sol–gel transition from a chitin solution dissolved in a NaOH/urea aqueous system at low temperatures. Ag nanoparticles (AgNPs) were synthesized via an in situ reduction of silver nitrate using trisodium citrate dehydrate and were immobilized on chitin nanofibers to obtain composite microspheres that consist of nanofibers and AgNPs (NCM-Ag). The size of AgNPs could be controlled in the range of 10 to 70 nm, depending on the concentration of AgNO3. X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FT-IR) analyses showed that the chitin nanofibers have a strong affinity toward AgNPs, resulting from the interaction between the acetamino group of chitin and the AgNPs. The NCM-Ag exhibited a perfect nanoporous structure and high surface area, as well as high stability in organic solvents. Moreover, in the catalytic epoxidation of olefin (particularly, the conversion of styrene to styrene epoxide), NCM-Ag exhibited an excellent selectivity of up to 90%. Converting chitin powder into chitin microspheres using an environmentally friendly technique is a green process, which is beneficial for the large-scale synthesis of industrial products. More importantly, this work provides a green synthetic pathway for the construction of size-controlled noble metal nanoparticles immobilized on nanofiber support, which have a wide range of potential applications.

Characterization of transesterification reactions by Mucoromycotina lipases in non-aqueous media

Transesterification properties of Rhizomucor, Rhizopus, Mucor, Umbelopsis and Mortierella crude lipases were investigated in water-free systems using an UV spectrophotometric method. Conversion of p-nitrophenyl palmitate (pNPP) with ethanol was characterized under various reaction conditions. Best conversion yields were generally obtained at 40°C in n-heptane, but temperature of 50°C and the solvents hexane and isooctane proved to be also useful. Then, crude lipases from five strains, namely Rhizomucor miehei NRRL 5282, Rhizopus oryzae NRRL 1526, Rhizopus stolonifer SZMC 13609, Mucor corticolus SZMC 12031 and Mortierella echinosphaera CBS 575.75 were selected for further kinetic studies and to evaluate the effect of the acyl acceptors and donors with various chain lengths on the reaction. In general, ethanol up to 4.25mol/L concentration enhanced the catalytic activities, and a steady conversion with maximum yields ranging from 61.2% to 90.5% was obtained at about 96h. Replacement of ethanol as the acyl acceptor with methanol, isopropanol, n-butanol or n-hexanol resulted in lower conversions when incubated with the same concentration. The selected crude lipases demonstrated high initial affinity toward the medium-chain aryl esters with C8 and C12 acids. Esterification of palmitic acid with ethanol showed much slower catalysis rates resulting in less specific activities than transesterification. The high stability in organic solvents makes the investigated crude enzymes promising candidates for further studies aiming at the application in organic synthesis processes.

Cell surface display of Yarrowia lipolytica lipase Lip2p using the cell wall protein YlPir1p, its characterization, and application as a whole-cell biocatalyst.

The Yarrowia lipolytica lipase Lip2p was displayed on the yeast cell surface via N-terminal fusion variant using cell wall protein YlPir1p. The hydrolytic activity of the lipase displayed on Y. lipolytica cells reached 11,900 U/g of dry weight. However, leakage of enzyme from the cell wall was observed. The calculated number of recombinant enzyme displayed on the cell surface corresponds to approximately 6 × 10(5) molecules per cell, which is close to the theoretical maximum (2 × 10(6) molecules/cell). Furthermore, the leaking enzyme was presented as three N-glycosylated proteins, one of which corresponds to the whole hybrid protein. Thus, we attribute the enzyme leakage to the limited space available on the cell surface. Nevertheless, the surface-displayed lipase exhibited greater stability to short-term and long-term temperature treatment than the native enzyme. Cell-bound lipase retained 74 % of its original activity at 60 °C for 5 min of incubation, and 83 % of original activity after incubation at 50 °C during 5 h. Cell-bound lipase had also higher stability in organic solvents and detergents. The developed whole-cell biocatalyst was used for recycling biodiesel synthesis. Two repeated cycles of methanolysis yielded 84.1 and 71.0 % methyl esters after 33- and 45-h reactions, respectively.

Improvement of the stability and activity of the BPO-A1 haloperoxidase from Streptomyces aureofaciens by directed evolution

Haloperoxidases are oxygenases that catalyze the halogenation of a range of organic compounds without the need for additional high-cost cofactors. Thus, haloperoxidases with high activity and stability are desired for industrial application. In this study, a directed evolution approach was adopted to improve the thermostability of the homodimeric BPO-A1 haloperoxidase from Streptomyces aureofaciens. Among 1000 mutant BPO-A1 haloperoxidases, 2 mutants HT177 and HT507, having higher thermostabilities than the wild-type BPO-A1 haloperoxidase, were obtained by directed evolution. The residual activities of mutants HT177 and HT507 were 2.3- and 5.1-fold higher than that of wild-type BPO-A1, respectively, after incubation at 80°C for 1h. In addition, mutant HT177 showed higher stability in organic solvents, such as methanol, ethanol, dimethyl sulfoxide, and N,N-dimethylformamide, than the wild-type BPO-A1 haloperoxidase. Furthermore, mutant HT507 showed higher specific activity. Based on the evaluation of single-amino-acid-substituted mutants, stabilization of the α-helix conformation, substitution of amino acid residues located at the surface of the protein molecule, and enhancement of the interaction between subunits may account for the improvement in thermostability, organic solvent stability, and specific activity. Consequently, the thermostability, organic solvent stability, and specific activity of S. aureofaciens BPO-A1 haloperoxidase were successfully improved by a directed evolution approach.

Immobilization of carboxypeptidase from Sulfolobus solfataricus on magnetic nanoparticles improves enzyme stability and functionality in organic media.

BackgroundSuperparamagnetic iron oxide nanoparticles (MNP) offer several advantages for applications in biomedical and biotechnological research. In particular, MNP-based immobilization of enzymes allows high surface-to-volume ratio, good dispersibility, easy separation of enzymes from the reaction mixture, and reuse by applying an external magnetic field. In a biotechnological perspective, extremophilic enzymes hold great promise as they often can be used under non-conventional harsh conditions, which may result in substrate transformations that are not achievable with normal enzymes. This prompted us to investigate the effect of MNP bioconjugation on the catalytic properties of a thermostable carboxypeptidase from the hyperthermophilic archaeon Sulfolobus solfataricus (CPSso), which exhibits catalytic properties that are useful in synthetic processes.ResultsCPSso was immobilized onto silica-coated iron oxide nanoparticles via NiNTA-His tag site-directed conjugation. Following the immobilization, CPSso acquired distinctly higher long-term stability at room temperature compared to the free native enzyme, which, in contrast, underwent extensive inactivation after 72 h incubation, thus suggesting a potential utilization of this enzyme under low energy consumption. Moreover, CPSso conjugation also resulted in a significantly higher stability in organic solvents at 40°C, which made it possible to synthesize N-blocked amino acids in remarkably higher yields compared to those of free enzyme.ConclusionsThe nanobioconjugate of CPSso immobilized on silica-coated magnetic nanoparticles exhibited enhanced stability in aqueous media at room temperature as well as in different organic solvents. The improved stability in ethanol paves the way to possible applications of immobilized CPSso, in particular as a biocatalyst for the synthesis of N-blocked amino acids. Another potential application might be amino acid racemate resolution, a critical and expensive step in chemical synthesis.

Purification and characterization of a thermostable keratinolytic serine alkaline proteinase from Streptomyces sp. strain AB1 with high stability in organic solvents

A keratinolytic alkaline proteinase (KERAB) was isolated from Streptomyces sp. strain AB1. Based on MALDI-TOF mass spectrometry analysis, the purified enzyme is a monomer with a molecular mass of 29850.17 Da. The NH 2-terminal sequence of the enzyme was determined to be TQANPPSWGLDDIDQTAL. This keratinase was completely inhibited by phenylmethanesulfonyl fluoride (PMSF) and diiodopropyl fluorophosphates (DIFP), which suggests that it belongs to the serine protease family. Using keratin azure as a substrate, the optimum pH and temperature values for keratinase activity were pH 11.5 and 75 °C, respectively. This keratinase was stable between 30 and 60 °C and pH 4 and 11 for 4 and 96 h, respectively, and thermoactivity and thermostability were enhanced in the presence of 5 mM Mg 2+. Its catalytic efficiency was higher than those of SAPB-L31I/T33S/N99Y, nattokinase and subtilisin Carlsberg. KERAB exhibited stability to detergents and high resistance against organic solvents and was able to degrade feathers completely. These properties make KERAB a potential candidate for future applications in detergent formulations, dehairing during leather processing, and non-aqueous peptide biocatalysis.

Molecular imprinting of cyclodextrin glycosyltransferases from Paenibacillus sp. A11 and Bacillus macerans with γ‐cyclodextrin

Cyclodextrin glycosyltransferase catalyzes the formation of a mixture of cyclodextrins from starch by an intramolecular transglycosylation reaction. To manipulate the product specificity of the Paenibacillus sp. A11 and Bacillus macerans cyclodextrin glycosyltransferases towards the preferential formation of gamma-cyclodextrin (CD(8)), crosslinked imprinted proteins of both cyclodextrin glycosyltransferases were prepared by applying enzyme imprinting and immobilization methodologies. The crosslinked imprinted cyclodextrin glycosyltransferases obtained by imprinting with CD(8) showed pH and temperature optima similar to those of the native and immobilized cyclodextrin glycosyltransferases. However, the pH and temperature stability of the immobilized and crosslinked imprinted cyclodextrin glycosyltransferases were higher than those of the native cyclodextrin glycosyltransferases. When the catalytic activities of the native, immobilized and crosslinked imprinted cyclodextrin glycosyltransferases were compared, the efficiency of the crosslinked imprinted enzymes for CD(8) synthesis was increased 10-fold, whereas that for cyclodextrin hydrolysis was decreased. Comparison of the product ratios by high-performance anion exchange chromatography showed that the native cyclodextrin glycosyltransferases from Paenibacillus sp. A11 and Bacillus macerans produced CD(6) : CD(7) : CD(8) : > or = CD(9) ratios of 15 : 65 : 20 : 0 and 43 : 36 : 21 : 0 after 24 h of reaction at 40 degrees C with starch substrates. In contrast, the crosslinked imprinted cyclodextrin glycosyltransferases from Paenibacillus sp. A11 and Bacillus macerans produced cyclodextrin in ratios of 15 : 20 : 50 : 15 and 17 : 14 : 49 : 20, respectively. The size of the synthesis products formed by the crosslinked imprinted cyclodextrin glycosyltransferases was shifted towards CD(8) and > or = CD(9), and the overall cyclodextrin yield was increased by 12% compared to the native enzymes. The crosslinked imprinted cyclodextrin glycosyltransferases also showed higher stability in organic solvents, retaining 85% of their initial activity after five cycles of synthesis reactions.

Molecular hydrogel-immobilized enzymes exhibit superactivity and high stability in organic solvents

This communication describes the use of a molecular hydrogel to immobilize enzymes for catalyzing reactions in an organic solvent to attain superactivity and exceptional stability.

Molecular Cloning of the Gene Encoding Vibrio Metalloproteinase Vimelysin and Isolation of a Mutant with High Stability in Organic Solvents

Vimelysin is a unique metalloproteinase from Vibrio sp. T1800 exhibiting high activity at low temperature and high stability in organic solvents such as ethanol. A 1,821 bp open reading frame of the vimelysin gene encoded 607 amino acid residues consisting of an N-terminal pro-region, a mature enzyme, and a C-terminal pro-region. The mature enzyme region showed 80%, 57% and 35% sequence identity with the mature forms of vibriolysin from V. vulnificus, pseudolysin from Pseudomonas aeruginosa, and thermolysin from Bacillus thermoproteolyticus, respectively. The catalytic residues and zinc-binding motifs of metalloproteinases are well conserved in vimelysin. The vimelysin gene was expressed in E. coli JM109 cells and the recombinant enzyme was purified as a 38-kDa mature form from cell-free extracts. The purified recombinant enzyme is indistinguishable from the enzyme purified directly from Vibrio. To obtain mutants exhibiting higher stability in organic solvents, random mutations were introduced by error-prone PCR and 600 transformants were screened. The N123D mutant exhibits two times higher stability in organic solvents than the wild-type enzyme. A plausible mechanism for the stability of the N123D mutant in organic solvents was discussed based on homology models of vimelysin and the N123D mutant.

Interlayer Esterification of Layered Silicic Acid−Alcohol Nanostructured Materials Derived from Alkoxytrichlorosilane

Layered silicic acid-organic nanohybrid materials consisting of long-chain alkoxy groups attached to thin silica layers have been prepared via esterification of a layered silicic acid-alcohol nanostructured material derived from hexadecoxytrichlorosilane (C(16)H(33)OSiCl(3)). The esterification reaction was performed by heating the layered composite. The detailed characterization of the product heated at 80 degrees C revealed that the interlayer alcohol molecules partly ( approximately 50%) reacted with the interlayer surface silanol groups to form alkoxy groups. Unreacted alcohol molecules were removed by tetrahydrofuran (THF) treatment to form a novel alkoxylated layered silica material. This product retains its structure up to 120 degrees C and has a higher stability in organic solvents if compared with the layered silicic acid-alcohol nanocomposite before esterification, whose structure collapsed over 100 degrees C. Furthermore, various alcohols can be adsorbed into the esterified nanohybrid with the expansion of the interlayer spacing.

Lipases - Enzymes for Biocatalytic Asymmetric Synthesis

Lipases (triacylglycerol ester hydrolases, EC 3.1.1.3) are found in most organisms and are known to catalyze the hydrolysis of triglycerides in vivo. [1] [2] They are some of the most studied and used biocatalysts in organic synthesis today. The versatility and popularity of lipases is attributed to their high catalytic efficiency on a broad range of substrates, combined with high regioselectivity and chiral recognition, [2] their high stability in organic solvents and at elevated temperatures, [2] [3] the reversibility of their mode of action into ester synthesis, [2] [4] their non-toxic and environmentally friendly nature, [5] and finally, their low cost.