Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| a new sunscreen of the cinnamate class: synthesis and enzymatic hydrolysis evaluation of glyceryl esters of p-methoxycinnamic acid. | glyceryl esters of p-methoxycinnamic acid, 1,3-dipalmitoyl-2-p-methoxycinnamoyl-1,2,3-propanetriol and 1,3-dioctanoyl-2-p-methoxycinnamoyl-1,2,3-propanetriol were synthesised in an attempt to increase substantivity and decrease eventual undesirable effects of sunscreens of this class. to assess if the glyceryl esters could present a higher stability towards hydrolysis by lipases in the stratum corneum, hydrolysis rates were determined in vitro using a commercial fungal lipase from rhizomucor mie ... | 2005 | 15854802 |
| chemical and physical properties of butterfat-vegetable oil blend spread prepared with enzymatically transesterified canola oil and caprylic acid. | structured lipid was synthesized from canola oil and caprylic acid with sn-1,3 specific lipase from rhizomucor miehei. cold spreadable butter was made by blending butterfat with the sl at a weight ratio of 80:20. its chemical and physical properties were compared with pure butter and butterfat-canola oil 80:20 blend spread. the butterfat-sl blend had lower contents of hypercholesterolemic fatty acids (fas) and the lowest atherogenic index (ai) as compared to the others. melting and crystallizati ... | 2005 | 15941341 |
| bioreactors based on immobilized cells. | for purification of oil-containing sewage water of oil-proceeding enterprises it has been elaborated by authors the laboratory bioreactor on the basis of immobilized mycelial mucor miehei fungus cells with periodical and constant supply of purified solution. the purification process is tested on model and real oil-containing liquid wastes. it has been established that under true bioreactor exploitation, 1 g of mucor miehei immobilized cells enables to purify more than 100 l of sewage water, cont ... | 2001 | 15954606 |
| acrylamide-quenching of rhizomucor miehei lipase. | steady-state and time-resolved fluorescence-quenching measurements have been performed to study multitryptophan lipase from filamentous fungus rhizomucor miehei. using the steady-state acrylamide fluorescence quenching data and the fluorescence-quenching-resolved-spectra (fqrs) method, the total emission spectrum of native ("closed-lid") lipase has been decomposed into two distinct spectral components accessible to acrylamide. according to fqrs analysis, more quenchable component has a maximum o ... | 2005 | 15963433 |
| hydrolyzable nonionic surfactants: stability and physicochemical properties of surfactants containing carbonate, ester, and amide bonds. | a linear and a branched nonionic cleavable surfactants containing a carbonate bond have been prepared from tetra(ethylene glycol) and an alkylchloroformate. the stability of these carbonate surfactants was determined by investigating their hydrolysis and biodegradability characteristics. the hydrolysis was catalyzed by alkali or enzymes (esterase from porcine liver and lipases from mucor miehei and candida antarctica b) and was monitored using 1h nmr. it was found that the stability toward alkal ... | 2005 | 15979083 |
| lipase-catalyzed acidolysis of tripalmitin with hazelnut oil fatty acids and stearic acid to produce human milk fat substitutes. | structured lipids (sls) containing palmitic, oleic, stearic, and linoleic acids, resembling human milk fat (hmf), were synthesized by enzymatic acidolysis reactions between tripalmitin, hazelnut oil fatty acids, and stearic acid. commercially immobilized sn-1,3-specific lipase, lipozyme rm im, obtained from rhizomucor miehei was used as the biocatalyst for the enzymatic acidolysis reactions. the effects of substrate molar ratio, reaction temperature, and reaction time on the incorporation of ste ... | 2005 | 15998148 |
| copolymeric polythioesters by lipase-catalyzed thioesterification and transthioesterification of alpha,omega-alkanedithiols. | linear copolymeric polythioesters [pte; poly(alpha,omega-alkanedioic acid-co-alpha,omega-alkanedithiols)] were formed in good yield (approximately 69%) by thioesterification of 1,12-dodecanedioic acid with 1,6-hexanedithiol and 1,8-octanedithiol, respectively, catalyzed by immobilized lipase from rhizomucor miehei (lipozyme rm im) in vacuo without a solvent. similarly, transthioesterification (thiolysis) of diethyl 1,12-dodecanedioate with 1,6-hexanedithiol led to the formation of approximately ... | 2006 | 16007456 |
| synthesis of acylglycerols from omega-3 fatty acids and conjugated linoleic acid isomers. | n-3 pufa (omega-3 polyunsaturated fatty acid) concentrate from mackerel oil enriched in epa (eicosapentaenoic acid) and dha (docosahexaenoic acid) was used to esterify isomers of cla (conjuated linoleic acid) to produce acylglycerols (glycerides). catalysis was potentiated by immobilized lipases from the yeast candida antarctica and the mould mucor miehei. c. antarctica lipase showed higher reactivity and much faster initial rate of incorporation of cla into acylglycerols than its m. miehei coun ... | 2006 | 16008528 |
| polyhydric alcohol protective effect on rhizomucor miehei lipase deactivation enhanced by pressure and temperature treatment. | the influence of polyhydric alcohols (sorbitol, xylitol, erythritol, glycerol) on the thermal stability of rhizomucor miehei lipase has been studied at high hydrostatic pressure (up to 500 mpa). in the absence of additives, a protective effect (pe) (the ratio between the residual activities determined at 480 mpa for the enzyme in the presence or absence of polyhydric alcohols) of low-applied pressures (from 50 mpa to 350 mpa) against thermal deactivations (at 50 degrees c and 55 degrees c) has b ... | 2005 | 16044285 |
| quantization of ph: evidence for acidic activity of triglyceride lipases. | here we present a study of lipolytic activity of lipases from fusarium solani pisi (cutinase), rhizomucor miehei, pseudomonas cepacia, and humicola lanuginosa. their activities toward triolein provide clear evidence for considerable enzymatic activity under acidic conditions. the activity was followed using fourier transform infrared attenuated total reflection (ftir-atr) and nuclear magnetic resonance (nmr). using these approaches, all the lipases that were studied exhibited lipolytic activity ... | 2005 | 16114894 |
| production of biodiesel by lipase-catalyzed transesterification of vegetable oils: a kinetics study. | kinetics of production of biodiesel by enzymatic methanolysis of vegetable oils using lipase has been investigated. a mathematical model taking into account the mechanism of the methanolysis reaction starting from the vegetable oil as substrate, rather than the free fatty acids, has been developed. the kinetic parameters were estimated by fitting the experimental data of the enzymatic reaction of sunflower oil by two types of lipases, namely, rhizomucor miehei lipase (rm) immobilized on ion-exch ... | 2005 | 16209548 |
| adsorption of lipase on hollow fiber membrane chips. | the amount of lipase from mucor miehei adsorption on ultrafiltration polysulfone hollow fiber membrane chips has been determined using different lipase concentrations at three different temperatures, namely 30, 35, and 40 degrees c. it was experimentally shown that adsorption of lipase increases with temperature. the results were used to evaluate the constants found in the langmuir adsorption isotherm model coupled with the van't hoff's relationship. a temperature dependence correlation for the ... | 2005 | 16317961 |
| substrate specificity and kinetic properties of enzymes belonging to the hormone-sensitive lipase family: comparison with non-lipolytic and lipolytic carboxylesterases. | we have studied the kinetics of hydrolysis of triacylglycerols, vinyl esters and p-nitrophenyl butyrate by four carboxylesterases of the hsl family, namely recombinant human hormone-sensitive lipase (hsl), est2 from alicyclobacillus acidocaldarius, afest from archeoglobus fulgidus, and protein rv1399c from mycobacterium tuberculosis. the kinetic properties of enzymes of the hsl family have been compared to those of a series of lipolytic and non-lipolytic carboxylesterases including human pancrea ... | 2005 | 16325466 |
| [effect of chemical modification of lipase on the regulation of its lipolytic activity in reversed micelles]. | hydrophilized and hydrophobized forms of the lipase from mucor miehei were obtained by its chemical modification with cellobiose and n-hydroxysuccinimidyl palmitate with a modification degree of 4 in both cases. a comparative analysis of the regulation of the catalytic activities of the native and modified lipases was carried out in the system of reversed micelles of ot aerosol (aot) in isooctane. the level of catalytic activity of all the lipase preparations in the micellar medium was found to ... | 2005 | 16363131 |
| spectroscopic and catalytic studies of lipases in ternary hexane-1-propanol-water surfactantless microemulsion systems. | a series of water-in-oil microemulsion systems formulated without surfactant were used to solubilize lipases from rhizomucor miehei and candida antarctica b. the effect of the system's composition on the velocity of enzymic reactions was investigated following a model esterification reaction. the interaction between enzymes and the microemulsion environment was studied by steady state fluorescence spectroscopy. the site of localization of the enzyme within the different microdomains of the dispe ... | 2006 | 16364610 |
| angiotensin converting enzyme inhibitory activity of amino acid esters of carbohydrates. | l-alanyl-d-glucose, l-valyl-d-glucose, l-phenylalanyl-d-glucose and l-phenylalanyl-lactose esters were synthesized enzymatically using two lipases viz., rhizomucor miehei lipase (rml) and porcine pancreas lipase (ppl) and tested for their potential as inhibitors of angiotensin converting enzyme (ace) in vitro. the esters exhibited concentration related ace inhibitory activity. the potency of the various esters measured in terms of ic50 values were as follows: l-phenylalanyl-d-glucose, ic50-0.121 ... | 2006 | 16529809 |
| lipase-catalyzed esterification of 2-monoricinolein for 1,2 (2,3)-diricinolein synthesis. | the purpose of this investigation was to develop conditions for producing 2-monoricinoleoyl dag. we used lipase-catalyzed hydrolysis of triricinolein to obtain 2-monoricinolein and thereafter synthesized 1,2(2,3)-diricinolein through esterification of 2-monoricinolein, using ricinoleic acid as the acyl donor. five different 1,3-specific immobilized lipases were tested for the initial methanolysis reaction: candida antarctica type b, rhizomucor miehei, rhizopus oryzae (rol), thermomyces lanuginos ... | 2006 | 16555475 |
| dialkyl 3,3'-thiodipropionate and dialkyl 2,2'-thiodiacetate antioxidants by lipase-catalyzed esterification and transesterification. | medium- and long-chain dialkyl 3,3'-thiodipropionate antioxidants such as dioctyl 3,3'-thiodipropionate, didodecyl 3,3'-thiodipropionate, dihexadecyl 3,3'-thiodipropionate, and di-(cis-9-octadecenyl) 3,3'-thiodipropionate were prepared in high yield by lipase-catalyzed esterification and transesterification of 3,3'-thiodipropionic acid and its dimethyl ester, respectively, with the corresponding medium- or long-chain 1-alkanols, i.e., 1-octanol, 1-dodecanol, 1-hexadecanol, and cis-9-octadecen-1- ... | 2006 | 16608215 |
| solvent-free lipase-catalyzed preparation of long-chain alkyl phenylpropanoates and phenylpropyl alkanoates. | an enzymatic method was developed for the preparation of medium- or long-chain alkyl 3-phenylpropenoates (alkyl cinnamates), particularly alkyl hydroxy- and methoxy-substituted cinnamates such as oleyl p-coumarate and oleyl ferulate. the various alkyl cinnamates were formed in high to moderate yield by lipase-catalyzed esterification of cinnamic acid and its analogues with fatty alcohols in vacuo at moderate temperatures in the absence of drying agents and solvents. immobilized candida antarctic ... | 2006 | 16608217 |
| antifungal and antibacterial activities of araucaria araucana (mol.) k. koch heartwood lignans. | five lignans (secoisolariciresinol, pinoresinol, eudesmin, lariciresinol, and lariciresinol-4-methyl ether) were isolated from an meoh extract from araucaria araucana (mol.) k. koch wood for the first time in this species and their structures determined with spectroscopic methods. the antimicrobial activities of these compounds were determined for the bacteria citrobacter sp., bacillus subtilis, escherichia coli, micrococcus luteus, staphylococcus aureus, and pseudomonas aeruginosa, and for the ... | 2006 | 16610214 |
| synthesis of structured lipids containing medium-chain and omega-3 fatty acids. | the ability of different lipases to incorporate omega3 fatty acids, namely, eicosapentaenoic acid (epa, c20:5n-3), docosapentaenoic acid (dpa, c22:5n-3), and docosahexaenoic acid (dha, c22:6n-3), into a high-laurate canola oil, known as laurical 35, was studied. lipases from mucor miehei (lipozyme-im), pseudomonas sp. (ps-30), and candida rugosa (ay-30) catalyzed optimum incorporation of epa, dpa, and dha into laurical 35, respectively. other lipases used were candida anatrctica (novozyme-435) a ... | 2006 | 16756372 |
| optimisation of n-octyl oleate enzymatic synthesis over rhizomucor miehei lipase. | octyl oleate is a useful organic compound with several applications in cosmetic, lubricant and pharmaceutical industry. at first, the enzymatic synthesis of n-octyl oleate by direct lipase-catalysed esterification of oleic acid and 1-octanol was investigated in a stirred batch reactor in solvent-free system. a systematic screening and optimisation of the reaction parameters were performed to gain insight into the kinetics mechanism. particularly, enzyme concentration, reaction temperature, stirr ... | 2006 | 16770594 |
| characteristics of structured lipid prepared by lipase-catalyzed acidolysis of roasted sesame oil and caprylic acid in a bench-scale continuous packed bed reactor. | structured lipid (sl) was prepared from roasted sesame oil and caprylic acid (ca) by rhizomucor miehei lipase-catalyzed acidolysis in a bench-scale continuous packed bed reactor. total incorporation and acyl migration of ca in the sl were 42.5 and 3.1 mol %, respectively, and the half-life of the lipase was 19.2 days. the sl displayed different physical and chemical properties, less saturated dark brown color, lower viscosity, lower melting and crystallization temperature ranges, higher melting ... | 2006 | 16819927 |
| adverse effect of chloride impurities on lipase-catalyzed transesterifications in ionic liquids. | the adverse influence of chloride impurities on the lipase-catalyzed transesterification in ionic liquid is described. the activity of lipase from rhizomucor miehei exponentially decreased with increasing cl(-) content in 1-octyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl] amide, [omim][tf(2)n], and the activity of lipase in [omim][tf(2)n] mixture containing 2% [omim] [cl] was only about 2% of the activity in pure [omim][tf(2)n]. the activity of lipase from candidantarctica linearly decre ... | 2006 | 16820978 |
| lipase-catalyzed reactions at different surfaces. | starting from gold chips, we have tailor-made three surfaces by the self-assembly monolayer technique: one entirely hydrophobic, one hydrophobic with dispersed carboxyl groups, and one hydrophilic, containing hydroxyl groups. rhizomucor miehei lipase has been adsorbed to the hydrophobic and the hydrophilic surfaces and covalently bound to the surface containing carboxyl groups. the adsorption of two substrates-capric acid (decanoic acid) and monocaprin-on the lipase-covered surfaces was monitore ... | 2006 | 16952258 |
| highly efficient preparation of lipophilic hydroxycinnamates by solvent-free lipase-catalyzed transesterification. | various medium- or long-chain alkyl cinnamates and hydroxycinnamates, including oleyl p-coumarate as well as palmityl and oleyl ferulates, were prepared in high yield by lipase-catalyzed transesterification of an equimolar mixture of a short-chain alkyl cinnamate and a fatty alcohol such as lauryl, palmityl, and oleyl alcohol under partial vacuum at moderate temperature in the absence of solvents and drying agents in direct contact with the reaction mixture. immobilized lipase b from candida ant ... | 2006 | 16968063 |
| optimal formation of hexyl laurate by lipozyme im-77 in solvent-free system. | a medium-chain ester, hexyl laurate, with fruity flavor is primarily used in personal care formulations as an important emollient for cosmetic applications. to conform to the "natural" interests of consumers, the ability of immobilized lipase from rhizomucor miehei (lipozyme im-77) to catalyze the direct esterification of hexanol and lauric acid by using a solvent-free system was investigated in this study. response surface methodology (rsm) and four-factor-five-level central composite rotatable ... | 2006 | 16968072 |
| combining regio- and enantioselectivity of lipases for the preparation of (r)-4-chloro-2-butanol. | preparation of 98% ee (r)-4-chloro-2-butanol was carried out by the enzymatic hydrolysis of chlorohydrin esters, using fungal resting cells and commercial enzymes. hydrolyzes were carried out using lipases from candida antarctica (novozym 435), c. rugosa, rhizomucor miehei (lipozyme im), burkolia cepacia, and resting cells of rhizopus oryzae and aspergillus flavus. the influence of the enzyme, the solvent, the temperature, and the alkyl chain length on the selectivity of hydrolyzes of isomeric m ... | 2007 | 17089342 |
| chemo-enzymatic preparation of copolymeric polythioesters containing branched-chain thioether groups. | branched-chain copolymeric polythioesters (pte) were formed in good yield (approximately 87%) by chemoenzymatic reactions including thiyl radical-induced addition of 1,6-hexanedithiol to the >c=c< double bond of dimethyl 1,18-octadec-9-enedioate and transthioesterification of polyfunctional dimethyl 1,18-octadec-9-enedioate with bifunctional 1,6-hexanedithiol catalyzed by immobilized lipase from rhizomucor miehei. the reactions were performed in vacuo at 80 degrees c without a solvent. pte was e ... | 2007 | 17103159 |
| higher order structure of mucor miehei lipase and micelle size in cetyltrimethylammonium bromide reverse micellar system. | the higher order structure of mucor miehei lipase and micelle size in a cationic cetyltrimethylammonium bromide (ctab) reverse micellar system was investigated. circular dichroic (cd) measurement revealed that the lipase far-uv cd spectra changed markedly, going from buffer solution to the reverse micellar solution, and were very similar for any organic solvent used. the ellipticity of the solubilized lipase in the far-uv region markedly decreased with increasing water content (w(0): molar ratio ... | 2007 | 17169622 |
| exploiting the pressure effect on lipase-catalyzed wax ester synthesis in dense carbon dioxide. | the present work focuses on the thermodynamic interpretation of the lauryl oleate biosynthesis in high-pressure carbon dioxide. lipase-catalyzed lauryl oleate production by oleic acid esterification with 1-dodecanol over immobilized lipase from rhizomucor miehei (lipozyme rm im) was successfully performed in a sapphire window batch stirred tank reactor (bstr) using dense co(2) as reaction medium. the experiments were planned to elucidate the pressure effect on the reaction performance. with incr ... | 2007 | 17221889 |
| acidolysis of tristearin with selected long-chain fatty acids. | five lipases, namely, candida antarctica (novozyme-435), mucor miehei (lipozyme-im), pseudomonas sp. (ps-30), aspergillus niger (ap-12), and candida rugosa (ay-30), were screened for their effect on catalyzing the acidolysis of tristearin with selected long-chain fatty acids. among the lipases tested c. antarctica lipase catalyzed the highest incorporation of oleic acid (oa, 58.2%), gamma-linolenic acid (gla, 55.9%), eicosapentaenoic acid (epa, 81.6%), and docosahexaenoic acid (dha, 47.7%) into ... | 2007 | 17288439 |
| fermentation and antimicrobial activities of extracts from different species of fungus belonging to genus, trichoderma. | the present paper discusses the effects of the crude extracts of trichoderma spp. on a number of fungal and bacterial organisms. these include paecilomyces variotii, penicillium notatum, nematospora corylii, mucor miehei, bacillus brevis, bacillus subtilis, enterobacter dissolvens and sarcina lutea. the culture broth extracts of different isolates of trichoderma harzianum, t. longibrachiatum and t. koningii cultured in different media were investigated individually for in-vitro antifungal and an ... | 2004 | 17298115 |
| inhibition of rhizomucor miehei and candida rugosa lipases by d-glucose in esterification between l-alanine and d-glucose. | a detailed kinetic study of the esterification of d-glucose with l-alanine catalyzed by lipases from rhizomucor miehei (rml) and candida rugosa (crl) showed that both lipases follow the ping-pong bi-bi mechanism, in which l-alanine and d-glucose bind in subsequent steps releasing water and l-alanyl-d-glucose, with competitive substrate inhibition by d-glucose at higher concentrations leading to the formation of dead-end lipase.d-glucose complexes. an attempt to obtain the best fit of this kineti ... | 2007 | 17368393 |
| enzymatic production of infant milk fat analogs containing palmitic acid: optimization of reactions by response surface methodology. | infant milk fat analogs resembling human milk fat were synthesized by an enzymatic interesterification between tripalmitin, coconut oil, safflower oil, and soybean oil in hexane. a commercially immobilized 1,3-specific lipase, lipozyme rm im, obtained from rhizomucor miehei was used as a biocatalyst. the effects of substrate molar ratio, reaction time, and incubation temperature on the incorporation of palmitic acid at the sn-2 position of the triacylglycerols were investigated. a central compos ... | 2007 | 17430912 |
| native-like tertiary structure in the mucor miehei lipase molten globule state obtained at low ph. | studies on the acid-induced denaturation of mucor miehei lipase (e.c. 3.1.1.3) were performed by circular dichroism (cd) spectroscopy, fluorescence emission spectroscopy and binding of hydrophobic dye, 1-anilino 8-naphthalenesulfonic acid (ans). acid denaturation of the lipase showed loss of secondary structure and alterations in the tertiary structure in the ph range 4 to 2 and 7 to 2 respectively, suggesting that the lipase exists as an acid-unfolded state approximately ph 2.0. a further decre ... | 2007 | 17487689 |
| lipase-catalyzed regioselective synthesis of steryl (6'-o-acyl)glucosides. | the regioselective acylation of cholesteryl beta-d-glucoside, at the c-6 of the glucose moiety, was achieved using microbial lipases in organic solvents. with palmitic acid as an acyl donor 81 or 63% conversions of cholesteryl glucoside to its 6'-o-palmitoyl derivative were obtained using candida antarctica or rhizomucor miehei enzymes, respectively. high yields (64-92%) were also obtained with fatty acids 6:0-22:0 and 16:1 (n-7). the synthesis of cholesteryl (6'-o-palmitoyl)glucoside was also a ... | 2007 | 17549435 |
| production, purification and application-relevant characterisation of an endo-1,3(4)-beta-glucanase from rhizomucor miehei. | growth on a wheat bran media induced production of an extracellular beta-glucanase by rhizomucor miehei (dsm 1330). the enzyme was purified to homogeneity. substrate specificity studies coupled with protein database similarity searching using mass spectrometry-derived sequence data indicate it to be an endo-1,3(4)-beta-glucanase (ec 3.2.1.6). the enzyme was characterised in terms of potential suitability for use in animal (poultry) feed. significant activity was observed over the entire ph range ... | 2007 | 17589838 |
| superficially active water in lipid membranes and its influence on the interaction of an aqueous soluble protease. | the purpose of this paper is to demonstrate that the interaction of an aqueous soluble enzyme with lipid membranes is influenced by the lipid composition of the interphase. the results show that the interaction of an aqueous soluble protease, rennet from mucor miehei, depends on the exposure of the carbonyl and phosphate groups at the membrane interphase. the changes produced by the protease on the surface pressure of monolayers of dimyristoylphosphatidylcholine (dmpc); dioleoylphosphatidylcholi ... | 2007 | 17662235 |
| attb site disruption in marine actinomyces sp. m048 via dna transformation of a site-specific integration vector. | an efficient conjugation method has been developed for the marine actinomyces sp. isolate m048 to facilitate the genetic manipulation of the chandrananimycin biosynthesis gene cluster. a phic31-derived integration vector pij8600 containing orit and attp fragments was introduced into strain m048 by bi-parental conjugation from escherichia coli et12567 to strain m048. transformation efficiency was (6.38+/-0.41)x10(-5) exconjugants per recipient spore. analysis of eight exconjugants showed that the ... | 2008 | 17678501 |
| the lipase-catalyzed hydrolysis of lutein diesters in non-aqueous media is favored at extremely low water activities. | the enzymatic hydrolysis of a mixture of lutein diesters from marigold flower (tagetes erecta) was performed both in organic solvents and supercritical co(2) (sc-co(2)) using two commercial lipases: lipase b from candida antarctica (novozym 435) and the lipase from mucor miehei (lipozyme rm im). both lipases showed an unexpected dependence of initial reaction rate with the initial water activity (a(wi)) in hexane, with the highest rates of hydrolysis taking place at the lowest a(wi) of the bioca ... | 2007 | 17724756 |
| the allosteric modulation of lipases and its possible biological relevance. | during the development of an enantioselective synthesis using the lipase from mucor miehei an unusual reaction course was observed, which was analyzed precisely. for the first time an allosteric modulation of a lipase changing its selectivity was shown. | 2007 | 17825093 |
| enantioselective transacetylation of (r,s)-beta-citronellol by propanol rinsed immobilized rhizomucor miehei lipase. | use of enzymes in low water media is now widely used for synthesis and kinetic resolution of organic compounds. the frequently used enzyme form is the freeze-dried powders. it has been shown earlier that removal of water molecules from enzyme by rinsing with n-propanol gives preparation (prep) which show higher activity in low water media. the present work evaluates prep of the lipase (from rhizomucor miehei) for kinetic resolution of (r,s)-beta-citronellol. the acylating agent was vinyl acetate ... | 2007 | 17880741 |
| highly regioselective enzymatic synthesis of polymerizable derivatives of methyl shikimate. | regiocontrollable selectivity of enzymatic method for synthesis of polymerizable derivatives of methyl shikimate was described. lipase acrylic resin from candida antarctica (cal-b) and immobilized lipase from mucor miehei (mml) showed high regioselectivity toward the secondary hydroxyl of methyl shikimate, which presents three hydroxyl groups with similar reactivity. catalysis by mml in acetone facilitated the single step synthesis of 5-o-acyl methyl shikimate derivatives in high yields, while t ... | 2007 | 17976984 |
| hypolipidemic effect of oils with balanced amounts of fatty acids obtained by blending and interesterification of coconut oil with rice bran oil or sesame oil. | blended oils comprising coconut oil (cno) and rice bran oil (rbo) or sesame oil (seso) with saturated fatty acid/monounsaturated fatty acid/polyunsaturated fatty acid at a ratio of 1:1:1 and polyunsaturated/saturated ratio of 0.8-1 enriched with nutraceuticals were prepared. blended oils (b) were subjected to interesterification reaction using sn-1,3 specific lipase from rhizomucor miehei. fatty acid composition and nutraceutical contents of the blended oil were not affected by interesterificati ... | 2007 | 17994696 |
| synthesis and characterization of canola oil-stearic acid-based trans-free structured lipids for possible margarine application. | incorporation of stearic acid into canola oil to produce trans-free structured lipid (sl) as a healthy alternative to partially hydrogenated fats for margarine formulation was investigated. response surface methodology was used to study the effects of lipozyme rm im from rhizomucor miehei and candida rugosa lipase isoform 1 (lip1) and two acyl donors, stearic acid and ethyl stearate, on the incorporation. lipozyme rm im and ethyl stearate gave the best result. gram quantities of sls were synthes ... | 2007 | 18052237 |
| novel chromatographic resolution of chiral diacylglycerols and analysis of the stereoselective hydrolysis of triacylglycerols by lipases. | in the present study, we propose a general and accessible method for the resolution of enantiomeric 1,2-sn- and 2,3-sn-diacylglycerols based on derivatization by isocyanates, which can be easily used routinely by biochemists to evaluate the stereopreferences of lipases in a time course of triacylglycerol (tag) hydrolysis. diacylglycerol (dag) enantiomers were transformed into carbamates using achiral and commercially available reagents. excellent separation and resolution factors were obtained f ... | 2008 | 18162167 |
| structural basis for the cold adaptation of psychrophilic m37 lipase from photobacterium lipolyticum. | the m37 lipase from photobacterium lipolyticum shows an extremely low activation energy and strong activity at low temperatures, with optimum activity seen at 298 k and more than 75% of the optimum activity retained down to 278 k. though the m37 lipase is most closely related to the filamentous fungal lipase, rhizomucor miehei lipase (rml) at the primary structure level, their activity characteristics are completely different. in an effort to identify structural components of cold adaptation in ... | 2008 | 18186467 |
| biocompatible microemulsions based on limonene: formulation, structure, and applications. | the preparation of biocompatible (w/o) microemulsions based on r-(+)-limonene, water, and a mixture of lecithin and either 1-propanol or 1,2-propanediol as emulsifiers was considered. the choice of the compositions of the microemulsions used was based on the pseudo-ternary phase diagrams of the four-component system determined at 30 degrees c for different weight ratios of the components. when 1-propanol was considered as co-surfactant, the area of the microemulsion zone was remarkably increased ... | 2008 | 18303927 |
| monoglycerides and diglycerides synthesis in a solvent-free system by lipase-catalyzed glycerolysis. | five lipases were screened (thermomyces lanuginosus free and immobilized forms, candida antarctica b, candida rugosa, aspergillus niger, and rhizomucor miehei) to study their ability to produce monoglycerides (mg) and diglycerides (dg) through enzymatic glycerolysis of soybean oil. lipase from c. antarctica was further studied to verify the enzyme load (wt% of oil mass), the molar ratio glycerol/oil, and the water content (wt% of glycerol) on the glycerolysis reaction. the best dg and mg product ... | 2008 | 18421596 |
| esterification reactions catalyzed by lipases immobilized in organogels: effect of temperature and substrate diffusion. | rhizomucor miehei lipase was immobilized in hydroxy(propylmethyl) cellulose or agar gels containing lecithin or aot microemulsions. the effect of the diffusion of substrates and products to this catalyst was studied, as well as the effect of temperature on the initial rate of ester synthesis. the composition of the gel affects the reaction rate due to mass transport phenomena. the apparent activation energies were higher for the systems based on agar, independently of the microemulsion used, and ... | 2008 | 18427927 |
| characterization of fluoroalcohols-induced intermediates of mucor miehei lipase at low ph. | we have previously characterized an acid-unfolded (u(a)) state of mucor miehei lipase at ph 2. the effect of 2,2,2-trifluoroethanol (tfe) and 1,1,1,3,3,3-hexafluoroisopropanol (hfip) resulted in characterization of molten-globule (mg) like states with beta-sheet secondary structure at 15% (v/v) tfe and 6% (v/v) hfip. alpha-helical states accumulate at 80% (v/v) tfe and 30% (v/v) hfip. | 2008 | 18473945 |
| lipases at interfaces: unique interfacial properties as globular proteins. | the adsorption behavior of two globular proteins, lipase from rhizomucor miehei and beta-lactoglobulin, at inert oil/water and air/water interfaces was studied by the pendant drop technique. the kinetics and adsorption isotherms were interpreted for both proteins in different environments. it was found that the adopted mathematical models well describe the adsorption behavior of the proteins at the studied interfaces. one of the main findings is that unique interfacial properties were observed f ... | 2008 | 18512870 |
| direct separation of monoacylglycerol isomers by enantioselective high-performance liquid chromatography. | an hplc-based method for separation of isomers of monoacylglycerols (mags) was established using an enantioselective column, chiralcel of. three mag isomers, i.e. sn-1-mag, sn-2-mag and sn-3-mag, having the same acyl groups were baseline separated with resolution factor of more than 1.2 between adjacent peaks. in addition, mixtures of enantiomer pairs of mag species (sn-1 and sn-3-mags) having different acyl groups could be resolved with partial overlaps of some peaks. the sn-1 and sn-3 molecula ... | 2008 | 18550069 |
| production of citronellyl acetate in a fed-batch system using immobilized lipase. scientific note. | several reports exist in the literature citing the decrease in conversion rates of organic-phase catalytic synthesis reactions when acetic acid is present as a reaction component. this inhibition is thought to result from damage to either the hydration layer-protein interaction or the overall enzyme structure. in this work, the inhibitory effect of acetic acid on lipase enzyme activity was ameliorated by conducting syntheses under acetic acid-limiting conditions in a fed-batch system, resulting ... | 1998 | 18576031 |
| production of glycerides from glycerol and fatty acid by immobilized lipases in non-aqueous media. | immobilized mucor miehei lipase catalyzes synthesis reactions between glycerol and oleic acid. no organic solvent is necessary to solubilize the substrates, which allows for the use of a reaction medium solely composed of the necessary substrates. water produced in the reaction evaporates due to the high temperature used for the process. a conversion of 86% of oleic acid into triolein is obtained when using the substrates in stoichiometric amounts. varying the ratio of glycerol over oleic acid a ... | 1990 | 18592508 |
| kinetics of lipase-catalyzed esterification in supercritical co(2). | this study compares two solvents for enzymatic reactions: supercritical carbon dioxide (scco(2)) and organic solvent (n-hexane). the model reaction that was chosen was the esterification of oleic acid by ethanol catalyzed by an immobilized lipase from mucor miehei (lypozyme). the stability of the enzyme appeared to be quite good and similar in both media but was affected by the water content. partition of water between solvents and immobilized enzyme has been calculated from experimental adsorpt ... | 1992 | 18600942 |
| enzymatic reaction kinetic: comparison in an organic solvent and in supercritical carbon dioxide. | myristic acid esterification has been performed by an immobilized lipase from mucor miehei both in n-hexane and in supercritical carbon dioxide (scco(2)). the enzyme is stable in scco(2) at 15 mpa and 323 k. the reaction rate is influenced by the concentration of water and by the reaction medium composition. a reaction mechanism is proposed, and kinetic parameters are determined at 12.5 mpa and 313 k. maximum velocity appears 1.5-fold higher in scco(2) than in n-hexane; however, as solubility of ... | 1992 | 18601120 |
| kinetic study of the lipase-catalyzed synthesis of triolein. | the kinetics of the synthesis of triolein catalyzed by immobilized mucor miehei lipase were studied. equilibrium constants for the synthesis of mono-, di-, and triolein were calculated from the equilibrium compositions for different initial ratios of glycerol and oleic acid by means of multiresponse regression. the 1,3-specific lipase can catalyze the synthesis of triolein because the ester enzymatically formed with the primary alcohol isomerizes, through acyl migration, to an ester on the secon ... | 1993 | 18601287 |
| immobilization of lipase for effective interesterification of fats and oils in organic solvent. | in order to investigate quantitatively the interesterification reaction, triolein and stearic acid were used as substrates and eight commercially available lipases were tested for their suitability for the reaction. three fungal lipase preparations were found to be suitable. the hydrolytic activity of the commercial lipases was tested with olive oil, and it was noted that there was no correlation between their hydrolytic and interesterification activities. among the lipases tested, mucor miehei ... | 1993 | 18609539 |
| blueprint for a lipase support: use of hydrophobic controlled-pore glasses as model systems. | for the commercial exploitation of lipase biocatalysis to be successful, it is essential that effective supports are selected for lipase immobilization. in this study hydrophobic controlled-pore glasses have been used as model systems for the immobilization of rhizomucor miehei lipase. the effect of pore diameter and surface chemistry on enzyme efficiency in a typical esterification reaction under essentially nonaqueous conditions has been examined. it has been found that pore diameters of at le ... | 1994 | 18615440 |
| influence of water activity on the synthesis of triolein catalyzed by immobilized mucor miehei lipase. | the influence of the thermodynamic activity of water (a(w))on the synthesis of triolein catalyzed by mucor miehei lipase was investigated. its effect on the equilibrium and on the rates of the different reactions present, esteification and mono- and diglyceride isomerization, was evaluated through measurements made in controlled water activity atmosphere. the apparent equilibrium constants were measured from the concentration of the different species as a function of the intial glycerol-to oleic ... | 1995 | 18623094 |
| studies on the lipozyme-catalyzed synthesis of butyl laurate. | the effects of temperature, speed of agitation, enzyme concentration, etc., on butyl laurate synthessis using mucor miehei lipase (lipozymetrade mark) have been studied. although the soluble enzyme was quite thermcstable in aqeous solution, it deactivated rapidly at and above 40 degrees c in the presence of butanol. this enzyme immobilized on an anion-exchange resin (lipozymetrade mark) showed enhanced stability (as compared to the soluble form) to denaturation by butanol under the same conditio ... | 1995 | 18623256 |
| factors affecting the esterification of lauric acid using an immobilized biocatalyst: enzyme characterization and studies in a well-mixed reactor. | the esterification of lauric acid with geraniol catalyzed by the commercially immobilized lipase preparation from mucor miehei, lipozyme(r), was studied in well-stirred flasks. the enzyme support was characterized in terms of its internal and external surface area, protein location, and protein content. it was found that the enzyme was mainly located on the external surface of the support, therefore, internal diffusional limitations were not important. it was also shown that the protein content ... | 1995 | 18623264 |
| influence of water activity on the synthesis of triolein catalyzed by immobilized mucor miehei lipase. | 1995 | 18623374 | |
| comparison of hydrolysis and esterification behavior of humicola lanuginosa and rhizomucor miehei lipases in aot-stabilized water-in-oil microemulsions: i. effect of ph and water content on reaction kinetics. | lipolase and lipozyme are produced in large quantities (as a result of genetic engineering and overexpression) for the detergents market and provide a cheap source of highly active biocatalysts. humicola lanuginosa lipase (hil) and rhizomucor miehei lipase (rml) have been isolated in partially purified form from commercial preparations of lipolase and lipozyme, respectively. these lipases were solubilized in aerosol-ot (aot)-stabilized water-in-oil (w/o) microemulsions in n-heptane. hil and rml ... | 1995 | 18623462 |
| comparison of hydrolysis and esterification behavior of humicola lanuginosa and rhizomucor miehei lipases in aot-stabilized water-in-oil microemulsions: ii. effect of temperature on reaction kinetics and general considerations of stability and productivity. | humicola lanuginosa lipase (hil) and rhizomucor miehei lipase (rrnl), isolated from commercial preparations of lipolase and lipozyme, respectively, were solubilized in aot-stabilized water-in-oil (w/o) microemulsions in n-heptane and aspects of their hydrolysis and condensation activity examined. the temperature dependence of hil hydrolysis activity in unbuffered r = 10 microemulsions matched very closely that for tributyrin hydrolysis by lipolase in an aqueous emulsion assay. apparent activatio ... | 1995 | 18623477 |
| remarkable activation of enzymes in nonaqueous media by denaturing organic cosolvents. | the rates of transesterification reactions catalyzed by the protease subtilisin carlsberg suspended in various anhydrous solvents at 30 degrees c can be increased more than 100-fold by the addition of denaturing organic cosolvents (dimethyl sulfoxide or formamide); in water, the same cosolvents exert no enzyme activation. at 4 degrees c, the activation effect on the lyophilized protease is even higher, reaching 1000-fold. marked enhancement of enzymatic activity in anhydrous solvents by formamid ... | 1996 | 18623557 |
| on the issue of interfacial activation of lipase in nonaqueous media. | the question of whether lipases can be activated by adsorption onto an interface in organic solvents was addressed using rhizomucor miehei lipase as a model. in aqueous solution, this enzyme was shown to undergo a marked interfacial activation. however, lipase (either lyophilized or precipitated from water with acetone) suspended in ethanol or 2-(2-ethoxyethoxy)ethanol containing triolein exhibited no jump in catalytic activity when the concentration of triolein exceeded its solubility in these ... | 1996 | 18626893 |
| the influence of the mode of enzyme preparation on enzymatic enantioselectivity in organic solvents and its temperature dependence. | the enantioselectivities of subtilisin carlsberg and rhizomucor miehei lipase in organic solvents are found to strongly depend on the method by which the enzymes are prepared. for the transesterification between sec-phenethyl alcohol and vinyl butyrate in dioxane at 7 degrees c, the enantioselectivity of subtilisin precipitated with isopropanol is more than twice that of the enzyme prepared by lyophilization from aqueous buffer. furthermore, the temperature dependence of the enantioselectivity i ... | 1996 | 18627092 |
| amphiphilic conetworks as activating carriers for the enhancement of enzymatic activity in supercritical co2. | enzymatic reactions in supercritical carbon dioxide (scco2) represent a way of combining the advantages of biocatalysis with the environmental benign nature of scco2 as a solvent. here we demonstrate that activities of enzymes in scco2 can be greatly enhanced by incorporating them into amphiphilic conetworks (apcns), a novel type of enzyme support. two sets of hydrophilic/scco2-philic apcns, poly(2-hydroxyethyl acrylate)-linked by-poly(dimethylsiloxane) (phea-l-pdms) and poly(2-hydroxyethyl acry ... | 2008 | 18646222 |
| identification and characterization of a lipase gene from antrodia cinnamomea. | a partial (634 bp) cdna clone, af1229, obtained from expressed sequence tags (ests) of solid-cultured basidiomes of antrodia cinnamomea is homologous to the lipase gene in rhizomucor miehei. 5'-rapid amplification of cdna ends (race) and 3'-race amplification showed that the full-length lipase gene, ac-lip, has a 912bp open reading frame (orf), a 183bp 5' non-coding region, and a 144bp 3' non-coding region. ac-lip contains the lipase consensus sequence, vtvvghslga, and encodes a 303-amino acid p ... | 2008 | 18652894 |
| langmuir-blodgett based lipase nanofilms of unique structure-function relationship. | proteins represent versatile building blocks for realization of nanostructured materials of unique structure-function relationship to be applied in nanobiotechnology. following a recent work [bruzzese, d., pastorino, l., pechkova, e., sivozhelezov, nicolini, c., increase of catalytic activity of lipase towards olive oil by langmuir-film immobilization of lipase, enzyme and microbial technology, submitted for publication.], the langmuir-blodgett technique was utilized to develop nanostructured cr ... | 2008 | 18721850 |
| cloning of the rhizomucor miehei 3-hydroxy-3-methylglutaryl-coenzyme a reductase gene and its heterologous expression in mucor circinelloides. | in this study, the gene hmgr encoding the 3-hydroxy-3-methylglutaryl-coenzyme a reductase (hmg-coa reductase) was cloned and characterized in the zygomycete fungus rhizomucor miehei. the hmgr gene comprises a total of 3,585 bp including the coding sequence of a 1,058 amino acids length putative protein and five introns (137, 83, 59, 60 and 69 bp in length) dispersed in the whole coding region. southern hybridization analysis revealed that the gene is present only in one copy in the r. miehei gen ... | 2009 | 18853273 |
| bioactive metabolites produced by chaetomium globosum, an endophytic fungus isolated from ginkgo biloba. | a novel cytotoxic chlorinated azaphilone derivative named chaetomugilin d (1), together with three known metabolites, chaetomugilin a (2), chaetoglobosins a (3) and c (4), has been isolated by a bioassay-guided fractionation from the etoac extract of the cultures of chaetomium globosum, an endophytic fungus found in the leaves of ginkgo biloba. structure of 1 was established by analyses of spectroscopic methods, including 2d-nmr experiments (cosy, noesy, hmqc, and hmbc). compounds 1-4 displayed ... | 2009 | 19246197 |
| [enzymatic synthesis of homogenous triacylglycerol in media without solvent]. | the study of triacylglycerols synthesis using 1,3-regiospecific immobilized rhizomucor miehei lipase (lipozyme) or non-regiospecific immobilized candida antarctica lipase (novozyme) as biocatalyst was carried out in pure substrates conditions. our results show that long-chain triacylglycerols were synthesized from glycerol and free fatty acids at a higher rate than medium-chain triacylglycerols which were themselves synthesized at a higher rate than short-chain ones. furthermore, it is clearly s ... | 2006 | 19388599 |
| on the nature of ionic liquids and their effects on lipases that catalyze ester synthesis. | free and immobilized lipases from candida antarctica (cala and calb), thermomyces lanuginosus (tll) and rhizomucor miehei (rml) were used as catalysts in the synthesis of butyl propionate by transesterification in reaction media consisting in nine different ionic liquids. enzyme activities were clearly dependent on the nature of the ions, the results being improving as the alkyl chain length of the imidazolium cation increased, and as a function of the type of anion ([pf(6)], [bf(4)] or [ethylsu ... | 2009 | 19428718 |
| [investigation on low power microwave irradiation-assisted enzymatic esterification in organic solvent by fluorescence spectroscopy]. | the authors studied the fluorescence change of immobilized lipase from rhizomucor miehei in the microwave assisted enzymatic esterification of caprylic acid and butanol in organic medium by investigating the fluorescence spectra in solvent or aqueous buffer after incubating the lipase with the solvent, caprylic acid and butanol under microwave irradiation, respectively. a comparison was made with the conventional heated enzymatic esterification in the solvents. both of the heating modes, the mic ... | 2009 | 19445220 |
| improvement of yarrowia lipolytica lipase enantioselectivity by using mutagenesis targeted to the substrate binding site. | lip2p lipase from yarrowia lipolytica was shown to be an efficient catalyst for the resolution of 2-bromo-arylacetic acid esters, an important class of chemical intermediates in the pharmaceutical industry. enantioselectivity of this lipase was improved by site-directed mutagenesis targeted to the substrate binding site. to guide mutagenesis experiments, the three-dimensional model of this lipase was built by homology modelling techniques by using the structures of lipases from rhizomucor miehei ... | 2009 | 19504508 |
| enhancing thermostability of a rhizomucor miehei lipase by engineering a disulfide bond and displaying on the yeast cell surface. | to increase the thermostability of rhizomucor miehei lipase, the software disulfide by design was used to engineer a novel disulfide bond between residues 96 and 106, and the corresponding double cysteine mutants were constructed. the r. miehei lipase mutant could be expressed by pichia pastoris in a free secreted form or could be displayed on the cell surface. the new disulfide bond spontaneously formed in the mutant r. miehei lipase. thermostability was examined by measuring of hydrolysis acti ... | 2009 | 19533118 |
| fatty acid selectivity of lipases during acidolysis reaction between triolein and saturated fatty acids varying from caproic to behenic acids. | the chain length selectivity of three immobilized lipases, namely, lipozyme tl im from thermomyces lanoginosus, lipozyme rm im from rhizomucor miehei, and novozym 435 from candida antarctica, was determined in acidolysis performed in hexane using the homologous series of even carbon number, saturated fatty acids (sfas) of 6-22 carbons. triolein with individual sfas or a mixture of equimolar quantities of sfas was used as the substrate. the effects of operating variables including the mole ratio ... | 2009 | 19645505 |
| structure and applications of a rhamnolipid surfactant produced in soybean oil waste. | soybean oil soapstock was utilized as an alternative carbon source for the production of rhamnolipids by pseudomonas aeruginosa lbi strain. the chemical composition and properties of the rhamnolipid mixture obtained were determined to define its potential applications. the chemical characterization of the rhamnolipid has revealed the presence of ten different homologues. the monorhamnolipid rhac10c1) and the dirhamnolipid rha2c10c10 were the main components of the mixture that showed predominanc ... | 2010 | 19649781 |
| a new beta-glucosidase gene from the zygomycete fungus rhizomucor miehei. | in this study, a beta-glucosidase coding gene (bgl) of the zygomycete fungus rhizomucor miehei has been cloned and characterized. the gene comprises a total of 2,826 bp including the coding sequence of a 717 amino acids length putative protein and 10 introns dispersed in the whole coding region. the putative n-and c-terminal catalytic domains (aa 68 to aa 274 and aa 358-601, respectively) were identified; the two domains are connected with a 84-amino-acids linker. the catalytic region showed an ... | 2010 | 19813101 |
| fatty acid selectivity of lipases during acidolysis reaction between oleic acid and monoacid triacylglycerols. | with the aim of determining the fatty acid (fa) selectivity of lipases, a mixture of oleic acid and monoacid triacylglycerols (tags) including tricaproin (t6), tricaprylin (t8), tricaprin (t10), trilaurin (t12), trimyristin (t14), tripalmitin (t16) and tristearin (t18) was used as the substrate in acidolysis performed in hexane. three immobilized lipases, namely, lipozyme tl im from thermomyces lanoginosus, lipozyme rm im from rhizomucor miehei and novozym 435 from candida antarctica, were used ... | 2009 | 19835376 |
| kinetics of enzymatic trans-esterification of glycerides for biodiesel production. | in this paper, the reaction of enzymatic trans-esterification of glycerides with ethanol in a reaction medium containing hexane at a temperature of 37 degrees c has been studied. the enzyme was lipase from mucor miehei, immobilized on ionic exchange resin, aimed at achieving high catalytic specific surface and recovering, regenerating and reusing the biocatalyst. a kinetic analysis has been carried out to identify the reaction path; the rate equation and kinetic parameters have been also calcula ... | 2010 | 19902261 |
| preparation of (s)-1-halo-2-octanols using ionic liquids and biocatalysts. | preparation of (s)-1-chloro-2-octanol and (s)-1-bromo-2-octanol was carried out by the enzymatic hydrolysis of halohydrin palmitates using biocatalysts. halohydrin palmitates were prepared by various methods from palmitic acid and 1,2-octanediol. a tandem hydrolysis was carried out using lipases from candida antarctica (novozym 435), rhizomucor miehei (lipozyme im), and "resting cells" from a rhizopus oryzae strain that was not mycotoxigenic. the influence of the enzyme and the reaction medium o ... | 2009 | 19924063 |
| characterization of wine rennet and its kinetics by gel electrophoresis. | the rennet of glutinous rice wine (wine rennet) is an exclusive clotting agent for chinese royal cheese production. some characterizations are reported herein in an attempt to provide evidence about the use of the protease as either a rennet substitute or an accelerator in cheese making and ripening. the results showed that wine rennet was a monomeric and unglycosylated protease. the n-sequencing indicated a high degree of similarity to other fungal rennets. the cleavage sites of wine rennet on ... | 2010 | 20172203 |
| identification of acid- and thermotolerant extracellular beta-glucosidase activities in zygomycetes fungi. | extracellular beta-glucosidase activity of 94 strains, representing 24 species of the genera gilbertella, mucor, rhizomucor , and rhizopus was evaluated in submerged culture and under solid state fermentation on wheat bran. gilbertella persicaria g1 isolate showed the highest activity (70.9 u ml -1 ) followed by other gilbertella (58.6-59.0 u ml -1 ) and rhizomucor miehei isolates (29.2-42.0 u ml -1 ). optimum temperature for enzyme production was 25 degrees c for gilbertella and mucor , and 30 ... | 2010 | 20194103 |
| substrate conformations set the rate of enzymatic acrylation by lipases. | acrylates represent a class of alpha,beta-unsaturated compounds of high industrial importance. we investigated the influence of substrate conformations on the experimentally determined reaction rates of the enzyme-catalysed transacylation of methyl acrylate and derivatives by ab initio dft b3lyp calculations and molecular dynamics simulations. the results supported a least-motion mechanism upon the sp(2) to sp(3) substrate transition to reach the transition state in the enzyme active site. this ... | 2010 | 20301160 |
| diversity of thermophilic fungi in tengchong rehai national park revealed by its nucleotide sequence analyses. | the geothermal sites near neutral and alkalescent thermal springs in tengchong rehai national park were examined through cultivation-dependent approach to determine the diversity of thermophilic fungi in these environments. here, we collected soils samples in this area, plated on agar media conducive for fungal growth, obtained pure cultures, and then employed the method of internal transcribed spacer (its) sequencing combined with morphological analysis for identification of thermophilic fungi ... | 2010 | 20437144 |
| production, physiochemical and antimicrobial properties of fungal chitosan from rhizomucor miehei and mucor racemosus. | chitosan was isolated and purified from the mycelia of rhizomucor miehei and mucor racemosus. to characterize the extracted materials, their ftir spectra were compared with that of shrimp chitosan. final degree of deacetylation which determined by (1)h nmr was obtained as 98.6% for chitosan from r. miehei (named as c1) and 97.1% for chitosan from m. racemosus (named as c2), respectively. to investigate the antimicrobial properties of the isolated fungal chitosans, minimum inhibitory concentratio ... | 2010 | 20471417 |
| esterification of phenolic acids catalyzed by lipases immobilized in organogels. | lipases from rhizomucor miehei and candida antarctica b were immobilized in hydroxypropylmethyl cellulose organogels based on surfactant-free microemulsions consisting of n-hexane, 1-propanol and water. both lipases kept their catalytic activity, catalyzing the esterification reactions of various phenolic acids including cinnamic acid derivatives. high reaction rates and yields (up to 94%) were obtained when lipase from c. antarctica was used. kinetic studies have been performed and apparent kin ... | 2010 | 20490615 |
| one-pot enzymatic synthesis of docosahexaenoic acid-rich triacylglycerols at the sn-1(3) position using by-product from selective hydrolysis of tuna oil. | docosahexaenoic acid (dha)-rich oil has been industrially produced by selective hydrolysis of tuna oil with a lipase that acts weakly on dha. the free fatty acids (ffas) generated in this process as by-products contain a high dha concentration (46wt%) but are treated as industrial waste. this study attempted to reuse these by-product ffas using a one-pot process, and succeeded in producing triacylglycerols (tags) through the esterification of the by-product ffas with glycerol using immobilized r ... | 2011 | 20709631 |
| solvent-induced lid opening in lipases: a molecular dynamics study. | in most lipases, a mobile lid covers the substrate binding site. in this closed structure, the lipase is assumed to be inactive. upon activation of the lipase by contact with a hydrophobic solvent or at a hydrophobic interface, the lid opens. in its open structure, the substrate binding site is accessible and the lipase is active. the molecular mechanism of this interfacial activation was studied for three lipases (from candida rugosa, rhizomucor miehei, and thermomyces lanuginosa) by multiple m ... | 2010 | 20812327 |
| kinetically controlled synthesis of monoglyceryl esters from chiral and prochiral acids methyl esters catalyzed by immobilized rhizomucor miehei lipase. | partial acylation of only one primary hydroxyl group of glycerol generates a chiral center at position 2. rhizomucor miehei lipase (rml) catalyzes the kinetically controlled transesterification of different aromatic carboxylic acids methyl esters with glycerol. high synthetic yields of glyceryl esters (around 70-80%) were obtained even in the presence of significant concentrations of water (from 5% to 20%). after a long incubation of the reaction mixture in the presence of the biocatalyst only p ... | 2011 | 20855204 |
| exploring the conformational states and rearrangements of yarrowia lipolytica lipase. | we report the 1.7 å resolution crystal structure of the lip2 lipase from yarrowia lipolytica in its closed conformation. the lip2 structure is highly homologous to known structures of the fungal lipase family (thermomyces lanuginosa, rhizopus niveus, and rhizomucor miehei lipases). however, it also presents some unique features that are described and discussed here in detail. structural differences, in particular in the conformation adopted by the so-called lid subdomain, suggest that the openin ... | 2010 | 20923657 |
| poly(styrene-divinylbenzene) beads surface functionalized with di-block polymer grafting and multi-modal ligand attachment: performance of reversibly immobilized lipase in ester synthesis. | fibrous poly(styrene-b-glycidylmethacrylate) brushes were grafted on poly(styrene-divinylbenzene) (p(s-dvb)) beads using surface-initiated atom transfer radical polymerization. tetraethyldiethylenetriamine (tedeta) ligand was incorporated on p(gma) block. the ligand attached beads were used for reversible immobilization of lipase. the influences of ph, ionic strength, and initial lipase concentration on the immobilization capacities of the beads have been investigated. lipase adsorption capacity ... | 2011 | 21336640 |
| highly thermostable xylanase purified from rhizomucor miehei nrl 3169. | a thermostable xylanase was purified and characterized from the thermophilic fungus rhizomucor miehei (cooney & emerson) schipper. the enzyme was purified to homogeneity by ammonium sulfate precipitation, sephadex g-100 gel filtration and diethylaminoethyl cellulose anion exchange chromatography with a 29.1-fold. the enzyme was highly active within a range of ph from 5.0 to 6.5. the optimum temperature of the purified enzyme was 75-¦c. the enzyme showed high thermal stability at 70-¦c and 75-¦c ... | 2011 | 21388922 |
| hydrolysis of fish oil by hyperactivated rhizomucor miehei lipase immobilized by multipoint anion exchange. | rhizomucor miehei lipase (rml) is greatly hyperactivated (around 20- to 25-fold toward small substrates) in the presence of sucrose laurate. hyperactivation appears to be an intramolecular process because it is very similar for soluble enzymes and covalently immobilized derivatives. the hyperactivated enzyme was immobilized (in the presence of sucrose laurate) on cyanogen bromide-activated sepharose (very mild covalent immobilization through the amino terminal residue), on glyoxyl sepharose (int ... | 2011 | 21574268 |
| A comparison of lipase and trypsin encapsulated in mesoporous materials with varying pore sizes and pH conditions. | Immobilized enzymes have an advantage over enzymes free in solution in that they are easily recovered after completed reaction. In addition, immobilization often gives enhanced stability. Entrapment of an enzyme in the pores of a mesoporous material is an attractive procedure since the enzyme is immobilized without any covalent bonding to a support which may be detrimental to the catalytic performance. The objective of this work is to compare the encapsulation and catalytic performance of lipase ... | 2011 | 21733664 |