Publications

probing the substrate specificity for lipases. ii. kinetic and modeling studies on the molecular recognition of 2-arylpropionic esters by candida rugosa and rhizomucor miehei lipases.	racemic arylpropionic esters 1-3, precursors of therapeutically important non-steroidal antiinflammatory drugs, were subjected to hydrolyses in the presence of either candida rugosa or rhizomucor miehei crude lipases. the hydrolyses of 1 and 2 proved to be highly enantioselective, whereas 3 was not transformed at all. both the substrate specificity and the enantioselectivity of these lipases were explained through a molecular modeling study involving docking experiments between 1-3 and the amino ...	1997	9048908
molecular modelling studies of substrate binding to the lipase from rhizomucor miehei.	lipase enzymes have found increasingly widespread use, especially in biotransformation reactions in organic synthesis. due to their efficiency and high enantioselectivity, they can be employed in a variety of reactions to carry out asymmetric hydrolyses, esterifications and transesterifications. however, the reasons for their stereospecificity have not been fully correlated with the enzyme structure. employing molecular modelling techniques and existing experimental data, a transesterification r ...	1997	9263852
activity and stability of a rhizomucor miehei lipase in hydrophobic media.	the effects of detergents and organic solvents on a commercial lipase (lipozyme) from rhizomucor miehei were investigated. it was shown that the detergent sodium cholate is possibly an activator of the enzyme, increasing lipase activity 2.5 times (250% of the control) when the enzyme was preincubated with 7 mm cholate. lipozyme activity was over twice as high (230% of the control) in the presence of 80 mm tween 80 or 90 mm tween 20 (polyoxyethylenesorbitan monolaurate), apparently through an add ...	1997	9262001
enzymatic hydrolysis of anchovy oil: production of glycerides enriched in polyunsaturated fatty acids.	in an attempt to produce the polyunsaturated fatty acid (pufa)-enriched glycerides, commercially available turkish anchovy oil (pufa content of 27%), was hydrolyzed with 1,3-specific rhizomucor miehei lipase. after the hydrolysis, the triglyceride (tg), diglyceride (dg), monoglyceride (mg), and free fatty acid (ffa) composition of the reaction mixture was determined, and fatty acid components of these fractions were analyzed. r. miehei lipase released pufa extremely slowly, resulting in their ac ...	1997	9429299
conformational change in the activation of lipase: an analysis in terms of low-frequency normal modes.	the interfacial activation of rhizomucor miehei lipase (rml) involves the motion of an alpha-helical region (residues 82-96) which acts as a "lid" over the active site of the enzyme, undergoing a displacement from a "closed" to an "open" conformation upon binding of substrate. normal mode analyses performed in both low and high dielectric media reveal that low-frequency vibrational modes contribute significantly to the conformational transition between the closed and open conformations. in these ...	1998	9655340
anatomy of lipase binding sites: the scissile fatty acid binding site.	shape and physico-chemical properties of the scissile fatty acid binding sites of six lipases and two serine esterases were analyzed and compared in order to understand the molecular basis of substrate specificity. all eight serine esterases and lipases have similar architecture and catalytic mechanism of ester hydrolysis, but different substrate specificities for the acyl moiety. lipases and esterases differ in the geometry of their binding sites, lipases have a large, hydrophobic scissile fatt ...	1998	9720251
lipase specificity toward some acetylenic and olefinic alcohols in the esterification of pentanoic and stearic acids.	the esterification of five medium- and long-chain acetylenic alcohols (2-nonyn-1-ol, 10-undecyn-1-ol, 6-octadecyn-1-ol, 9-octadecyn-1-ol, and 13-docosyn-1-ol), seven olefinic alcohols (cis-3-nonen-1-ol, 10-undecen-1-ol, cis-6-octadecen-1-ol, cis-9-octadecen-1-ol, trans-9-octadecen-1-ol, trans-9, trans-11-octadecadien-1-ol, cis-9,cis-12-octadecadien-1-ol), and four short-chain unsaturated alcohols (allyl alcohol, 3-butyn-1-ol, 3-pentyn-1-ol, and cis-2-penten-1-ol) with pentanoic or stearic acid i ...	1998	9778133
a single step purification, immobilization, and hyperactivation of lipases via interfacial adsorption on strongly hydrophobic supports	a number of bacterial lipases can be immobilized in a rapid and strong fashion on octyl-agarose gels (e.g., lipases from candida antarctica, pseudomonas fluorescens, rhizomucor miehei, humicola lanuginosa, mucor javanicus, and rhizopus niveus). adsorption rates in absence of ammonium sulfate are higher than in its presence, opposite to the observation for typical hydrophobic adsorption of proteins. at 10 mm phosphate, adsorption of lipases is fairly selective allowing enzyme purification associa ...	1998	10099284
biocompatibility of potential wound management products: hydrogen peroxide generation by fungal chitin/chitosans and their effects on the proliferation of murine l929 fibroblasts in culture.	agaricus bisporus, fusarium graminearum, phycomyces blakesleeanus, unbleached and bleached, rhizomucor miehei, and rhizopus oryzae were examined as sources of fungal chitin/chitosan. the nitrogen content of the alkalitreated mycelia/sporangiophores obtained after optimization of culture conditions, and of similarly treated a. bisporus stipes, was 2.87, 1.29, 6.27, 6.50, 4.80, and 4.95% w/w, respectively, which relates to an estimated chitin content of 42, 19, 91, 94, 70, and 72%, respectively. t ...	1998	9457561
studies of lipase-catalyzed esterification reactions of some acetylenic fatty acids.	esterification of five positional isomers of acetylenic fatty acids [viz. 9:1(2a), 11:1(10a), 18:1(6a), 18:1(9a) and 22:1(13a)] of different chain lengths with n-butanol in n-hexane in the presence of eight different lipases [lipozyme im 20 (rhizomucor miehei), lipolase 100t (r. miehei), novozyme 435 (candida antarctica), ppl (porcine pancreatic lipase), ccl (c. cylindracea), ps-d (pseudomonas cepacia), lipase a-12 (aspergillus niger) and lipase ay-30 (c. rugosa)] was studied. 2-nonynoic acid wa ...	1998	9470175
crystal structure of the rhizomucor miehei aspartic proteinase.		1998	9561231
rhizomucor miehei aspartic proteinases having improved properties.		1998	9561232
anthranilamides: new antimicroalgal active substances from a marine streptomyces sp.	2-[methyl-(3-phenylpropionyl)amino]-benzoic acid (1e) was isolated from a culture of marine streptomyces sp. strain b7747. analogous compounds have potential importance as phytotoxic substances, hence compound 1e and the analogues 1a approximately 1d and 1f approximately 3a were synthesised. antimicroalgal activity of the anthranilamide analogues showed that esters 1b, 1f and 2b were more active than the free acids. the minimum inhibitory concentration (mic) against chlorella vulgaris, chlorella ...	1998	9589070
differentiation of rhizomucor species by carbon source utilization and isoenzyme analysis.	nineteen rhizomucor miehei and rhizomucor pusillus isolates were assayed for their ability to utilize 87 various substrates as a single carbon source. besides a difference in sucrose utilization, distinctive differences were found in the utilization of glycine, phenylalanine, and beta-alanine. five isoenzyme systems also proved useful for the determination of markers of distinctive value at a species level. data were used to obtain information about the genetic polymorphism of these species: a h ...	1998	9650990
simple conformation space search protocols for the evaluation of enantioselectivity of lipases.	two computational protocols have been evaluated regarding their ability to reproduce the enthalpic part of lipase enantioselectivity by forcefield potential energy differences (deltav#r-s). though the shortcomings of the approach are numerous, good qualitative results have been obtained here and elsewhere. the anticipated improvement of quantitative results by use of a second protocol, which did not impose any atom movement restrictions on the total system, was realized only in part. seemingly, ...	1998	9930664
1h-nmr on line monitoring of water activity during lipase catalysed esterification.	1h-nmr spectroscopy is used to determine simultaneously the water activity (aw) and the time course of an esterification reaction catalysed by a lipase. chemical shifts signals of hydroxylic hydrogens in fast exchange (i.e the average hydroxylic signal of acid, alcohol and water) varies with water activity and ester content. calibration curves have been established from model media composed of the substrates and various ester contents, at different water activities, in order to mimic a reaction ...	1998	9748540
chemical modification studies of rhizomucor miehei protease: evidence for the role of basic amino acids in enzyme catalysis.	the effect of chemical modification on milk clotting and proteolytic activities of aspartyl protease obtained from rhizomucor miehei nrrl 3500 was examined in the absence and the presence of its specific inhibitor pepstatin a. the effect on the ratio of milk clotting activity (mc) to proteolytic activity (pa), an index of the quality of milk clotting proteases was also determined. modification of the enzyme with trinitrobenzenesulfonic acid, diethylpyrocarbonate and phenylglyoxal produced an inc ...	1998	10412227
regioselective synthesis of ethoxylated glycoside esters using beta-glucosidase in supersaturated solutions and lipases in organic solvents	three ethoxylated glycosides, tetraethylene glycol beta-d-glucoside, tetraethylene glycol beta-d-xyloside, and methoxy triethyleneglycol beta-d-glucoside, were prepared via almond beta-glucoside-catalyzed (trans)glycosylation carried out in supersaturated solutions of glucose or p-nitrophenyl beta-d-xyloside and the respective polyethylene glycols. the products were isolated and further modified by enzymatic esterification with candida antarctica and mucor miehei lipases. the latter enzyme showe ...	1998	10099395
effect of salt hydrate pair on lipase-catalyzed regioselective monoacylation of sucrose.	sucrose monoesters of a fatty acid were synthesized by using lipase in a solvent-free system. when lipase from mucor miehei was used as a catalyst with capric acid as the donor and sugar as the acceptor, sucrose 6-monocaprate was predominantly produced in a yield of 25.3%. the yield of product was significantly increased by the direct addition of a suitable pair of solid salt hydrates to the reaction mixture to control the water activity (aw). among the salt hydrate pairs investigated, the bariu ...	1998	10099186
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
lipase-catalyzed production of short-chain acids terpenyl esters of interest to the food industry.	the production of low molecular weight esters as flavor compounds by biotechnological processes has a potential interest for the food industry. the use of natural available substrates and enzymes is an essential part of the process design, because the products may obtain natural label. in this study, direct esterification of citronellol and geraniol with short-chain fatty acids catalyzed by free lipase from mucor miehei was performed with high yields in n-hexane. the effects of the acid:alcohol ...	1999	15304771
a kinetic study on lipase-catalyzed interesterification of soybean oil with oleic acid in a continuous packed-bed reactor.	to provide a mathematical basis for the design and operation of a continuous, packed-bed reactor for the interesterification of soybean oil, soybean oil that contains 22.7% oleoyl and 54.3% linoleoyl moieties as molar acyl moiety composition was interesterified in hexane with oleic acid, using an immobilized sn-1,3-specific lipase (lipozyme im) from mucor miehei. the reaction was carried out in a u-shaped pyrex glass-made packed-bed reactor at 37 degrees c in the following system: concentration ...	1999	15304780
analysis of the dynamics of rhizomucor miehei lipase at different temperatures.	the dynamics of rhizomucor miehei lipase has been studied by molecular dynamics simulations at temperatures ranging from 200-500k. simulations carried out in periodic boundary conditions and using explicit water molecules were performed for 400 ps at each temperature. our results indicate that conformational changes and internal motions in the protein are significantly influenced by the temperature increase. with increasing temperature, the number of internal hydrogen bonds decreases, while surf ...	1999	10333171
highly selective synthesis of 1,3-oleoyl-2-palmitoylglycerol by lipase catalysis.	1,3-oleoyl-2-palmitoylglycerol (opo), an important structured triglyceride in infant nutrition, was synthesized by a two-step process in high yields and purity using sn1,3-regiospecific lipases. in the first step, tripalmitin (tp) was subjected to an alcoholysis reaction in an organic solvent catalyzed by sn1,3-regiospecific lipases yielding the corresponding 2-monopalmitin (2-mp). the 2-mp was isolated in up to 85% yield and >95% purity by crystallization and esterified in the second step with ...	1999	10417216
structure of the rhizomucor miehei aspartic proteinase complexed with the inhibitor pepstatin a at 2.7 a resolution.	crystals of rhizomucor miehei aspartic proteinase (rmp) complexed with pepstatin a grew in the orthorhombic space group p212121 and were isomorphous to native rmp crystals. the unit-cell dimensions are a = 41.52, b = 50.82, c = 172.71 a. there is one rmp-pepstatin a complex per asymmetric unit. the structure of the rmp-pepstatin a complex has been refined to a crystallographic r value of 19.3% and an rfree value of 28.0% at 2.7 a resolution. a pepstatin a molecule fits into the large substrate-b ...	1999	10089458
production of sophorolipids from whey. ii. product composition, surface active properties, cytotoxicity and stability against hydrolases by enzymatic treatment.	sophorolipids, obtained by a two-stage process starting from deproteinized whey concentrate using cryptococcus curvatus atcc 20509 and candida bombicola atcc 22214, were compared to products from one-stage processes, using different lipidic compounds as substrates. results showed that above all carbon source and not cultivation conditions had a distinct influence on the composition of the crude product mixture and therefore on the physicochemical and biological properties of the sophorolipids, s ...	1999	10570796
preparation of stearoyl lactic acid ester catalyzed by lipases from rhizomucor miehei and porcine pancreas optimization using response surface methodology.	the esterification reaction between stearic acid and lactic acid using rhizomucor miehei lipase and porcine pancreas lipase was optimized for maximum esterification using response surface methodology. the formation of the ester was found to depend on three parameters namely enzyme/substrate ratio, lactic acid (stearic acid) concentration and incubation period. the maximum esterification predicted by theoretical equations for both lipases matched well with the observed experimental values. in the ...	1999	10570805
substrate selectivity of various lipases in the esterification of cis- and trans-9-octadecenoic acid.	the substrate selectivity of numerous commercially available lipases from microorganisms, plants and animal tissue towards 9-octadecenoic acids with respect to the cis/trans configuration of the c=c double bond was examined by the esterification of cis- and trans-9-octadecanoic acid (oleic and elaidic acid respectively) with n-butanol in n-hexane. a great number of lipases studied, e.g. those from pseudomonas sp., porcine pancreas or carica papaya, were unable to discriminate between the isomeri ...	1999	10341430
enzymatic synthesis of unsaturated fatty acid glucoside esters for dermo-cosmetic applications.	unsaturated fatty acid alpha-butylglucoside esters were prepared by enzymatic esterification of alpha-butylglucoside in nonaqueous media. conditions were firstly optimized using oleic acid as acyl group. synthesis was possible in several solvents but the presence of water co-product in the medium limited the reaction to a thermodynamic equilibrium corresponding to a maximal conversion yield of 62%. in pure molten substrates, the removal of water under reduced pressure enabled yields superior to ...	1999	10397830
computational analysis of chain flexibility and fluctuations in rhizomucor miehei lipase.	we have performed molecular dynamics simulation of rhizomucor miehei lipase (rml) with explicit water molecules present. the simulation was carried out in periodic boundary conditions and conducted for 1. 2 ns in order to determine the concerted protein dynamics and to examine how well the essential motions are preserved along the trajectory. protein motions are extracted by means of the essential dynamics analysis method for different lengths of the trajectory. motions described by eigenvector ...	1999	10506284
enzyme-assisted acidolysis of borage (borago officinalis l.) and evening primrose (oenothera biennis l.) oils: incorporation of omega-3 polyunsaturated fatty acids.	lipase-catalyzed acidolysis of borage (borago officinalis l.) and evening primrose (oenothera biennisl.) oils with long-chain omega3 polyunsaturated fatty acids (pufa), namely, eicosapentaenoic (epa) and docosahexaenoic (dha) acids, was carried out in hexane, and the products were analyzed using gas chromatography. the most effective lipase for incorporation of omega3 pufa into these oils was pseudomonas sp. as compared to lipases from mucor miehei and candida antarctica. response surface method ...	1999	10552616
proteolytic activities of suparen and rennilase on buffalo, cow, and goat whole casein and beta-casein.	the proteolytic specificity and activity of mucor miehei protease (rennilase) and endothia parasitica protease (suparen) on buffalo, cow, and goat whole casein and beta-casein (cn) were studied by analyzing the degradation products. the results suggest that rennilase hydrolyzes casein of the three species in a manner similar to that of chymosin, resulting in the formation of alpha(s1)-i and beta-i, -ii, -iii as initial degradation fragments of alpha(s1)- and beta-cn. alpha(s1)-i was also the ini ...	1999	10552696
phylogeny and pcr identification of clinically important zygomycetes based on nuclear ribosomal-dna sequence data.	a molecular database for all clinically important zygomycetes was constructed from nucleotide sequences from the nuclear small-subunit (18s) ribosomal dna and domains d1 and d2 of the nuclear large-subunit (28s) ribosomal dna. parsimony analysis of the aligned 18s and 28s dna sequences was used to investigate phylogenetic relationships among 42 isolates representing species of zygomycetes reported to cause infections in humans and other animals, together with commonly cultured contaminants, with ...	1999	10565914
fluorescent inhibitors for the qualitative and quantitative analysis of lipolytic enzymes.	we report on the determination of active enzyme components in pure and crude lipases, using fluorescent inhibitors for covalent modification and visualization of the enzymatically active proteins. lipase-specific compounds are triacylglycerol analogs, namely 1,2(2, 3)-di-o-alkylglyceroalkylphosphonic acid-p-nitrophenyl esters, containing a fluorescent substituent bound to the omega-end of an alkyl chain. inhibitors derived from single-chain alcohols, such as p-nitrophenyl esters of fluorescent a ...	1999	10585746
enzymatic fatty acid exchange in digalactosyldiacylglycerol.	six different lipases were screened for their ability of acidolysis between digalactosyldiacylglycerol (dgdg) and heptadecanoic acid in toluene. lipases from geotrichum candidum, alcaligenes sp. and penicillium camembertii did not catalyse the acidolysis reaction. rhizopus arrhizus and rhizomucor miehei (lipozyme) catalysed the acidolysis but produced a mixture of dgmg, dgdg, acyl-dgmg and acyl-dgdg. the extra acyl group is bound to the primary hydroxyl of the digalactosyl moiety. candida antarc ...	2000	10660208
optimization of isoamyl acetate production by using immobilized lipase from mucor miehei by response surface methodology.	immobilized lipase from mucor miehei was employed for the esterification of isoamyl alcohol with acetic acid in n-heptane solvent. the important process variables studied were enzyme/substrate (e/s) ratio, alcohol (acid) concentration, and incubation period. based on box-behnken design of experiments, a second order response function was developed. the percentage esterification increased with both e/s ratio and time and decreased with alcohol (acid) concentration. the model indicated optimum con ...	2000	10689068
role of an electrostatic network of residues in the enzymatic action of the rhizomucor miehei lipase family.	we have used continuum electrostatic methods to investigate the role of electrostatic interactions in the structure, function, and ph-dependent stability of the fungal rhizomucor miehei lipase (rml) family. we identify a functionally important electrostatic network which includes residues s144, d203, h257, y260, h143, y28, r80, and d91 (residue numbering is from rml). this network consists of residues belonging to the catalytic triad (s144, d203, h257), residues located in proximity to the activ ...	2000	10715112
comparative fatty acid selectivity of lipases in esterification reactions with glycerol and diol analogues in organic media.	reaction selectivity of pseudomonas cepacia, rhizomucor miehei, and candida antarctica b lipases was assessed in multicompetitive esterification reaction mixtures containing an homologous series of n-chain even carbon number fatty acid (fa; c4-c18) substrates and a single alcohol cosubstrate (glycerol, 1,2-propanediol (1,2-pd), or 1, 3-propanediol (1,3-pd)) in tert-butyl methyl ether at water activity of 0.69 or 0.90 and a reaction temperature of 35 degrees c. for p. cepacia lipase, the ordinal ...	2000	10835238
the ribosomal dna of the zygomycete mucor miehei.	the ribosomal dna-from the zygomycete mucor miehei has been characterised. the complete rdna unit was cloned by heterologous pcr using primers whose sequence matched conserved regions of the rdna from related fungal species. the sequence of the overlapping pcr products revealed the existence of a repeated unit of 9574 bp. the genes encoding the different rrna species were identified by their homology to the corresponding sequences from other fungi. we estimate that the rdna unit is present in th ...	2000	10905432
intraspecific variation in two species of rhizomucor assessed by random amplified polymorphic dna analysis.	twenty-three rhizomucor isolates were characterized by random amplified polymorphic dna-pcr (rapd-pcr) with 10-bp oligonucleotide primers. these data were used for numerical analyses to obtain information on the intraspecific genetic polymorphism of rhizomucor species. the genetic variability in rhizomucor pusillus and rhizomucor miehei isolates was found to differ; the latter revealed less intraspecific polymorphism. the different levels of genotypic diversity suggest a correlation with the dif ...	2000	10986673
enzymatic synthesis of alpha-butylglucoside linoleate in a packed bed reactor for future pilot scale-up.	the enzymatic synthesis of a mixture of unsaturated fatty acid alpha-butylglucoside esters, containing more than 60% alpha-butylglucoside linoleate, was achieved through lipase-catalyzed esterification. the continuous evaporation under reduced pressure of the water produced enabled substrate conversions greater than 95% to be reached. two immobilized lipases from candida antarctica (chirazyme l2, c.-f., c2) and rhizomucor miehei (chirazyme l9, c.-f.) were compared in stirred batch and packed bed ...	2000	10933833
lipase-catalyzed modification of rice bran oil to incorporate capric acid.	capric acid (c10:0) was incorporated into rice bran oil with an immobilized lipase from rhizomucor miehei as the biocatalyst. effects of incubation time, substrate mole ratio, enzyme load, and water addition on mole percent incorporation of c10:0 were studied. transesterification was performed in an organic solvent, hexane, and under solvent-free condition. pancreatic lipase-catalyzed sn-2 positional analysis and tocopherol analysis were performed before and after enzymatic modification. product ...	2000	10995376
enantiomeric synthesis of (s)-2-methylbutanoic acid methyl ester, apple flavor, using lipases in organic solvent.	enantiomeric selective synthesis of (s)-2-methylbutanoic acid methyl ester, which is known as a major apple and strawberry flavor, was performed from racemic 2-methylbutanoic acid using lipases in organic solvent. among 20 lipases, lipase im 20 (immobilized lipase of rhizomucor miehei), lipase ap (aspergillus niger), and lipase fap-15 (aspergillus javanicus) exhibited higher enzymatic activities and enantioselectivities and were selected for the synthesis of (s)-2-methylbutanoic acid methyl este ...	2000	10691670
enzymatic esterification of ethanol by an immobilised rhizomucor miehei lipase in a perforated rotating disc bioreactor.	a perforated rotating disc bioreactor was developed to perform the esterification of ethanol with oleic acid, catalyzed by a lipase from rhizomucor miehei immobilized by adsorption on to a hydrophobic support-accurel ep700. the bioreactor with total recirculation operated at an optimum agitation rate of 400 rev./min. the experimental results, in this condition, were predict by a kinetic model using the constants obtained in the batch (erlenmeyer flasks) assays: a catalytic constant, k(cat) = 5.7 ...	2000	10713219
the atomic-resolution structure of a novel bacterial esterase.	a novel bacterial esterase that cleaves esters on halogenated cyclic compounds has been isolated from an alcaligenes species. this esterase 713 is encoded by a 1062 base pair gene. the presence of a leader sequence of 27 amino acids suggests that this enzyme is exported from the cytosol. esterase 713 has been over-expressed in agrobacterium without this leader sequence. its amino acid sequence shows no significant homology to any known protein sequence.	2000	10673440
lipase-mediated hydrolysis of blackcurrant oil.	four commercially available lipases, both free and immobilized, were tested for their ability to catalyze hydrolysis of blackcurrant (ribes nigrum) oil using two different approaches. the lipase from mucor miehei was studied free and immobilized in two different ways. the former series of enzymic reactions were performed in tap water at 40 degrees c, but the latter series of enzymic processes were carried out in mixtures of isooctane and phosphate buffer (in a typical 2/1 ratio of the components ...	2000	10978776
enzymatic resolution to (-)-ormeloxifene intermediates from their racemates using immobilized candida rugosa lipase.	in the synthesis of (-)-ormeloxifene, a drug candidate recently under development, enzymatic resolution of potential intermediates can be carried out using a simple, practical method. five commercially available lipases, candida rugosa lipase, candida antarctica lipase b, mucor miehei lipase, pseudomonas cepacia lipase, and humicola lanuginosa lipase, all immobilized on accurel(r), were initially screened in combination with four different substrates belonging to the class of phenyl esters. exce ...	2000	10861957
highly enantioselective esterification of racemic ibuprofen in a packed bed reactor using immobilised rhizomucor miehei lipase.	a systematic study of the enantioselective resolution of ibuprofen by commercial rhizomucor miehei lipase (lipozyme(r) im20) has been carried out using isooctane as solvent and butanol as esterificating agent. the main variables controlling the process (temperature, ibuprofen concentration, ratio butanol:ibuprofen) have been studied using an orthogonal full factorial experimental design, in which the selected objective function was enantioselectivity. this strategy has resulted in a polynomial f ...	2000	10862916
esterification of polyunsaturated fatty acids by various forms of immobilized lipase from rhizomucor miehei.	ethyl esterification specificity of a lipase from rhizomucor miehei for polyunsaturated fatty acids (pufa) was compared at 1 and 100 mm to study molecular recognition of pufa. the chemical shift of methylene adjacent to carboxyl groups in the nuclear magnetic resonance spectrum of docosahexaenoic acid (dha) in ethanol moved to a lower magnetic field as the concentration of dha increased, suggesting that the degree of dissociation of dha decreased. specificity constants or apparent second-order r ...	2000	10858032
continuous enzymatic esterification of glycerol with (poly)unsaturated fatty acids in a packed-bed reactor.	enzymatic synthesis of mono-, di-, and triacyglycerols from (poly)unsaturated fatty acids (linoleic, oleic, and conjugated linoleic acids) has been studied as a solvent-free reaction in a packed-bed reactor containing an immobilized lipase from mucor miehei. the extents of the esterification reactions of interest are primarily determined by the molar ratio of glycerol to fatty acid because the presence of excess glycerol as a immiscible phase is responsible for reducing the activity of the water ...	2000	10797243
kinetic modelling of the synthesis of 2-hydroxy-5-hexenyl 2-chlorobutyrate ester by an immobilised lipase.	an esterification process was developed for the direct synthesis of 2-hydroxy-5-hexenyl 2-chlorobutyrate ester from 2-chlorobutyric acid by using the epoxide 1,2-epoxy-5-hexene and mucor miehei immobilised lipase as the biocatalyst in a batch reactor. the effect of temperature, catalyst concentration, and substrate and product concentration has been studied. an ordered bi uni enzymatic mechanism with competitive inhibition by the epoxide and acid has been proposed. the corresponding kinetic para ...	2000	10828419
synthesis of glycerides containing n-3 fatty acids and conjugated linoleic acid by solvent-free acidolysis of fish oil.	menhaden oil, a rich source of n-3 fatty acids, was interesterified with conjugated linoleic acid (cla) in a reaction medium composed solely of substrates and either free or immobilized commercial lipase preparations. of five lipases tested, an immobilized preparation from mucor miehei provided the fastest rate of incorporation of cla into fish oil acylglycerols; however, and as observed with most of the lipases utilized, a significant proportion of the n-3 fatty acid residues were liberated in ...	2000	11042555
the his gap motif in microbial lipases: a determinant of stereoselectivity toward triacylglycerols and analogs.	lipases preferably hydrolyze the sn-1 and sn-3 acyl chain of triacylglycerols and sn-2 substituted analogs. molecular modeling studies of the stereopreference of microbial lipases from rhizopus oryzae, rhizomucor miehei, candida rugosa, and lipase b from candida antarctica toward the hydrolysis of triacylglycerols and analogs revealed that sterical interactions occurring between the sn-2 substituent and the his gap affect substrate geometry, which can be monitored by a single torsion angle. this ...	2000	11099801
regioselective enzymatic acylations of polyhydroxylated eudesmanes: semisynthesis, theoretical calculations, and biotransformation of cyclic sulfites.	different lipase enzymes have been tested in order to perform regioselective acetylations on the eudesmane tetrol from vulgarin. high yields (95%) of 1,12-diacetoxy derivative (4) were achieved in 1 h with candida antarctica lipase (cal). however, only the 12-acetyl derivative (6) was obtained in similar yield with mucor miehei (mml) or candida cylindracea (ccl) lipases. the enzymatic protection at c-1 and c-12 has been used to form eudesmane cyclic-sulfites between c-6 and c-4 atoms. the r/s-su ...	2000	11101376
papaya (carica papaya) lipase with some distinct acyl and alkyl specificities as compared with microbial lipases.	lipase from papaya (carica papaya) latex (cpl), candida antarctica lipase b (novozym 435, nov) and rhizomucor miehei lipase (lipozyme im 20, lip) were used as biocatalysts for the esterification of caprylic acid with straight-chain saturated c(4)-c(18) alcohols and unsaturated c(18) alcohols, such as cis-9-octadecenyl (oleyl, c(18:1), n-9), cis-6-octadecenyl (petroselinyl, c(18:1), n-12), cis-9,cis-12-octadecadienyl (linoleyl, c(18:2), n-6), all-cis-9,12,15-octadecatrienyl (alpha-linolenyl, c(18 ...	2000	11171278
selectivity of rhizomucor miehei lipase as affected by choice of cosubstrate system in ester modification reactions in organic media.	fatty acid (fa) selectivity of immobilized rhizomucor miehei lipase was determined for various cosubstrate systems for ester modification involving competing n-acyl-donor substrates of even-chain length (c4-c16; fa or their methyl esters, fame) and either n-propanol or propyl acetate in hexane. acyl-chain-length optima were observed for c8 and c14/16 in all cases. upon changing between cosubstrate systems of [fa + propanol] to [fame + propanol] to [fame + propyl acetate], there was a general shi ...	2000	10861401
lipase catalyzed synthesis of organic acid esters of lactic acid in non-aqueous media.	lipases from rhizomucor miehei (lipozyme im20) and porcine pancreas (ppl) were employed as catalysts for the esterification reaction between the hydroxyl group of lactic acid and the carboxyl group of organic acids. reactions were carried out at both shake-flask and bench-scale levels. various parameters, such as solvent, temperature, substrate and enzyme concentrations, effect of buffer volume, buffer ph and water volume, were investigated for optimization of yields. while ethylmethyl ketone (e ...	2001	11278035
enzymatic synthesis of isoamyl acetate using immobilized lipase from rhizomucor miehei.	the effects of important reaction parameters for enhancing isoamyl acetate formation through lipase-catalyzed esterification of isoamyl alcohol were investigated in this study. increase in substrate (acid) concentration led to decrease in conversions. a critical enzyme concentration of 3 g l(-1) was detected for a substrate concentration of 0.06 m (each of alcohol and acid). solvents with partition coefficient higher than 1000 (log p>3.0) supported enzyme activity to give high conversions. aceti ...	2001	11334663
alteration of lipase chain length specificity in the hydrolysis of esters by random mutagenesis.	the feasibility of altering the chain length specificity of industrially important rhizomucor miehei lipase was investigated by randomly mutating phe94 in the protein groove which is responsible for accommodating the acyl chain of the substrate. the recombinant lipase was initially expressed in e. coli. individual colonies were selected, grown, and the dna sequence of the lipase gene determined. fourteen of the 19 possible mutants were identified and each of these was transformed into pichia pas ...	2001	11344447
cloning and expression analysis of nhl1, a gene encoding an extracellular lipase from the fungal pea pathogen nectria haematococca mp vi (fusarium solani f. sp. pisi) that is expressed in planta.	the filamentous fungus nectria haematococca (anamorph fusarium solani f. sp. pisi) resides in soil, and attacks pea seedlings in the area of the underground epicotyl and upper tap root, causing foot rot disease. we detected lipase activity during in vitro growth of n. haematococca. subsequently, a lipase gene was cloned and functionally characterised by heterologous expression in saccharomyces cerevisiae. the full-length cdna of 1152 bp was cloned using a 3' race-pcr approach coupled with cdna l ...	2001	11361331
enantioselectivity of recombinant rhizomucor miehei lipase in the ring opening of oxazolin-5(4h)-ones.	enantioselectivity of enzyme catalysis is often rationalized via active site models. these models are constructed on the basis of comparing the enantiomeric excess of product observed in a series of reactions which are conducted with a range of homologous substrates, typically carrying various side chain substitutions. surprisingly the practical application of these simple but informative 'pocket size' models has been rarely tested in genetic engineering experiments. in this paper we report the ...	2001	11391019
phage display combinatorial libraries of short peptides: ligand selection for protein purification.	a library of heptapeptides displayed on the surface of filamentous phage m13 was evaluated as a potential source of affinity ligands for the purification of rhizomucor miehei lipase. two independent selection (biopanning) protocols were employed: the enzyme was either physically adsorbed on polystyrene or chemically immobilized on small magnetic beads. from screening with the polystyrene-adsorbed lipase it was found that there was a rapid enrichment of the library with "doublet" clones i.e. the ...	2001	11397457
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
effect of water activity and immobilization on fatty acid selectivity for esterification reactions mediated by lipases.	the effect of water activity (a(w)) and immobilization on fatty acid (fa) selectivity of burkholderia (formerly pseudomonas) cepacia, rhizomucor miehei, candida antarctica (type b), and candida rugosa lipases in esterification reactions was determined. studies were based on measuring ester formation in multicompetitive reaction mixtures containing either the homologous series of even carbon number n-chain saturated fa (c4-c18) or a series of n-chain (un)saturated fa (c18:x, where x = 0-3 double ...	2001	11536145
study of lipase-catalyzed hydrolysis of some monoterpene esters.	studies of the hydrolysis of bornyl, citronellyl, geranyl, and terpenyl acetates by commercially available lipases of candida rugosa, rhizopus arrhizus, and mucor miehei are presented. the hydrolysis of these monoterpene esters is investigated at various temperatures and phs, and the time dependence of the percentage of esters hydrolysed is studied. the catalytic activities of the lipases in hydrolysing the esters are compared and, overall, it is observed that under the experimental conditions u ...	2001	11400729
steryl and stanyl esters of fatty acids by solvent-free esterification and transesterification in vacuo using lipases from rhizomucor miehei, candida antarctica, and carica papaya.	sitostanol has been converted in high to near-quantitative extent to the corresponding long-chain acyl esters via esterification with oleic acid or transesterification with methyl oleate or trioleoylglycerol using immobilized lipases from rhizomucor miehei (lipozyme im) and candida antarctica (lipase b, novozym 435) as biocatalysts in vacuo (20-40 mbar) at 80 degrees c, whereas the conversion was markedly lower at 60 and 40 degrees c. corresponding conversions observed with papaya (carica papaya ...	2001	11714305
dynamics of the substrate binding pocket in the presence of an inhibitor covalently attached to a fungal lipase.	to gain insight into the mobility of the occupied ligand-binding pocket of the rhizomucor miehei lipase we have conducted a rigorous molecular dynamics analysis. the covalently attached inhibitor, ethylhexylphosphonate, was employed as a mimic of the putative tetrahedral intermediate in the esterolytic reaction. our results show that in this lipase, ligand recognition is influenced by the flexibility of the binding pocket, a feature that is common to many other enzymes. several regions around th ...	2001	11565841
synthesis of structured triacylglycerols containing caproic acid by lipase-catalyzed acidolysis: optimization by response surface methodology.	production in a batch reactor with a solvent-free system of structured triacylglycerols containing short-chain fatty acids by lipozyme rm im-catalyzed acidolysis between rapeseed oil and caproic acid was optimized using response surface methodology (rsm). reaction time (t(r)), substrate ratio (s(r)), enzyme load (e(l), based on substrate), water content (w(c), based on enzyme), and reaction temperature (t(e)), the five most important parameters for the reaction, were chosen for the optimization. ...	2001	11743762
development of small-size tubular-flow continuous reactors for the analysis of operational stability of enzymes in low-water systems.	a very small-scale continuous flow reactor has been designed for use with enzymes in organic media, particularly for operational stability studies. it is constructed from fairly inexpensive components, and typically uses 5 mg of catalyst and flow rates of 1 to 5 ml/h, so only small quantities of feedstock need to be handled. the design allows control of the thermodynamic water activity of the feed, and works with temperatures up to at least 80 degrees c. the reactor has been operated with both n ...	2001	11114661
optical resolution of asymmetric triacylglycerols by chiral-phase high-performance liquid chromatography.	a simple method for direct optical resolution of some asymmetric triacylglycerols (tgs) has been established. the method employs chiral-phase high-performance liquid chromatography (hplc). an enantiomeric pair of tgs comprising 1-eicosapentaenoyl-2,3-dicapryroyl-sn-glycerol (ecc) and 1,2-dicapryroyl-3-eicosapentaenoyl-sn-glycerol (cce) was resolved on a chiralcel of or on a chiralcel od column. the separation of another pair of asymmetric tgs, 1-docosahexaenoyl-2,3-dicapryroyl-sn-glycerol (dcc) ...	2001	11206777
tuning lipase enantioselectivity in organic media using solid-state buffers.	the enantioselectivity exhibited by candida antarctica lipase b (calb) in predominantly organic media has been studied for different enzyme protonation states. alcoholysis of (+/-)-2-phenyl-4-benzyloxazol-5(4h)-one (1) using butan-1-ol as the nucleophile in low-water organic solvents was used as a model reaction. using either organo-soluble bases or the newly introduced solid-state buffers of known pk(a), the protonation state of the lipase was altered. by choice of the appropriate solid-state b ...	2001	11463259
optimized synthesis of lipase-catalyzed hexyl acetate in n-hexane by response surface methodology.	hexyl acetate, a short-chain ester with fruity odor, is a significant green note flavor compound and widely used in the food industry. the ability for immobilized lipase from mucor miehei (lipozyme im-77) to catalyze the transesterification of hexanol with triacetin was investigated in this study. response surface methodology and five-level-five-factor central composite rotatable design were adopted to evaluate the effects of synthesis variables, such as reaction time (2-10 h), temperature (25-6 ...	2001	11312836
replacements of amino acid residues at subsites and their effects on the catalytic properties of rhizomucor pusillus pepsin, an aspartic proteinase from rhizomucor pusillus.	site-directed mutagenesis was carried out to investigate the functional roles of amino acid residues of rhizomucor pusillus pepsin (rmpp) in substrate-binding and catalysis. mutations of two amino acid residues, e13 in the s3 subsite and n219 in the s3/s4 subsites, caused marked changes in kinetic parameters for two substrate peptides with different sequences. further site-directed mutagenesis at e13 suggested that e13 plays a critical role in forming the correct hydrogen bond network around the ...	2001	11328603
lipase-catalysed hydrolysis of short-chain substrates in solution and in emulsion: a kinetic study.	we have studied the enzymatic hydrolysis of solutions and emulsions of vinyl propionate, vinyl butyrate and tripropionin by lipases of various origin and specificity. kinetic studies of the hydrolysis of short-chain substrates by microbial triacylglycerol lipases from rhizopus oryzae, mucor miehei, candida rugosa, candida antarctica a and by (phospho)lipase from guinea-pig pancreas show that these lipolytic enzymes follow the michaelis-menten model. surprisingly, the activity against solutions o ...	2001	11750885
effective enzymatic resolution of rac-1-(3-trifluoromethylphenyl)propan-2-ol, precursor of fenfluramine.	lipases from candida antarctica and from mucor miehei efficiently catalyze the enantioselective esterification of rac-1-(3-trifluoromethylphenyl)propan-2-ol. the obtained enantioforms are suitable to prepare both enantiomers of fenfluramine.	2002	11968073
microwave-assisted rapid characterization of lipase selectivities.	a rapid screening procedure for characterization of lipase selectivities using microwaves was developed. the rate of reaction of various commercial lipases (porcine pancreas, mucor miehei, candida rugosa, pseudomonas cepacia) as well as lipases from laboratory isolates-bacillus stearothermophilus and burkholderia cepacia rgp-10 for triolein hydrolysis was 7- to 12-fold higher in a microwave oven as compared to that by ph stat. the esterification of sucrose/methanol and ascorbic acid with differe ...	2002	12062110
enzymatic esterification of an acid with an epoxide using an immobilized lipase from mucor miehei as catalyst: optimization of the yield and isomeric excess of ester by statistical analysis.	we have developed the methodology for the esterification of an acid with an epoxide using 2-chlorobutyric acid and 1,2-epoxy-5-hexene catalysed by a mucor miehei-immobilized lipase. thus, this methodology could be applied to obtain 2-chloroesters. a factorial design of experiments and a central composite design have been used to optimise the synthesis of these esters. the variables chosen were temperature and initial catalyst concentration, while the responses were yield and isomeric excess of t ...	2002	12074092
[synthesis of partial glycerol caprates by using lipase in nonaqueous media].	enzymatic esterification by reacting caparic acid with glycerol in solvent-free system was studied. lipases from pseudomonas fluoresces(pfl), mucor miehei(mml) and candida antarictica(cal) possessed good catalytic activity. the optimal reaction conditions to convert capric acid with cal are: 60 degrees c, 20-100 u of cal per gram capric acid, 12% (w/w) of initial water content in glycerol. cal does not express its 1,3-specificity in final product. mechanical fraying denatured cal partly. 96.4% o ...	2002	12674646
pharacine, a natural p-cyclophane and other indole derivatives from cytophaga sp. strain am13.1.	from the ethyl acetate extract of the bacterial strain cytophaga sp. am13.1, among many known compounds, the new natural products 2,5-bis(3-indolylmethyl)pyrazine (2) and a highly symmetrical p-cyclophane named pharacine (5) were identified. in addition, tryptamine isovalerate (1) and p-hydroxyphenylacetamide (4), known as plant metabolites, were isolated and characterized from a microorganism for the first time. the new natural products showed no activity against three microalgae, the fungus mu ...	2002	12444694
5-[4-(1-hydroxyethyl)phenyl]-10,15,20-triphenylporphyrin as a probe of the transition-state conformation in hydrolase-catalyzed enantioselective transesterifications.	5-[4-(1-hydroxyethyl)phenyl]-10,15,20-triphenylporphyrin (1a) and zinc porphyrin 1b were designed and synthesized to experimentally examine the validity of the transition-state model previously proposed for the lipase-catalyzed kinetic resolution of secondary alcohols. the lipases from pseudomonas cepacia (lipase ps), candida antarctica (chirazyme l-2), rhizomucor miehei (chirazyme l-9), and pseudomonas aeruginosa (lipase lip) exhibited excellent enantioselectivity (e >100 at 30 degrees c). subt ...	2002	11925221
enantiomeric resolution of 2-aryl propionic esters with hyperthermophilic and mesophilic esterases: contrasting thermodynamic mechanisms.	the enantiomeric resolution of 2-aryl propionic esters by hyperthermophilic and mesophilic esterases was found to be governed by contrasting thermodynamic mechanisms. entropic contributions predominated for mesophilic esterases from candida rugosa and rhizomucor miehei, while enthalpic forces controlled this resolution by the esterase from the extremely thermoacidophilic archaeon, sulfolobus solfataricus p1. this disparity in thermodynamic mechanism can be attributed to the differences in confor ...	2002	12105890
phytotoxic arylethylamides from limnic bacteria using a screening with microalgae.	n-phenylethylamides 1a-1f, were isolated from cultures of three limnic strains gw90a, gw102a and gw73a. strain gw102a delivered additionally the compound cyclo(isoleucyldehydroalanyl) (2). the structure of these compounds were assigned by a detailed spectral analysis. due to their potential use as herbicides, various related compounds 1a, 3, 4a and 4b were synthesized. the minimum inhibitory concentration (mic) against chlorella vulgaris, chlorella sorokiniana, chlorella salina and scenedesmus s ...	2002	12243454
polar organic solvent added to an aqueous solution changes hydrolytic property of lipase.	for developing further uses of lipase as a biocatalyst, its hydrolytic activity toward some esters was investigated in a miscible solution composed of a buffer and a polar organic solvent. twenty percent dimethylformamide, 35% dimethylsulfoxide, 15% 1,4-dioxane, 15% dimethoxyethane, and 2% diethoxyethane promoted the hydrolysis by a lipase from rhizomucor miehei toward some hydrophobic substrates, 4-methylumbelliferyl oleate, 4-methylumbelliferyl palmitate, and monoolein. while hydrolysis by thi ...	2003	12951497
lipase-catalyzed methanolysis of triricinolein in organic solvent to produce 1,2(2,3)-diricinolein.	the objective of this study was to find the optimal parameters for lipase-catalyzed methanolysis of triricinolein to produce 1,2(2,3)-diricinolein. four different immobilized lipases were tested, candida antarctica type b (calb), rhizomucor miehei (rml), pseudomonas cepacia (pcl), and penicillium roquefortii (prl). n-hexane and diisopropyl ether (dipe) were examined as reaction media at three different water activities (a(w)), 0.11, 0.53, and 0.97. the consumption of triricinolein and the format ...	2003	14733366
general trend of lipase to self-assemble giving bimolecular aggregates greatly modifies the enzyme functionality.	three microbial lipases (those from candida rugosa, humicola lanuginosa, and mucor miehei) have been found to exhibit a tendency to form bimolecular aggregates in solution even at very low enzyme concentrations (44 microg/ml) in the absence of a detergent, as detected by gel filtration. the monomolecular form of the enzymes was found as unique only at low enzyme concentration and in the presence of detergents. however, in the case of the lipase b from candida antarctica, no bimolecular form coul ...	2003	12523838
effect of polar head groups on the activity of aspartyl protease adsorbed to lipid membranes.	the proteolytic activity of an aspartyl protease of mucor miehei was correlated with the adsorption of the protease to lipid vesicles. it was observed that the presence of phosphatidylethanolamines (pe's) in the membrane increased the enzyme activity in a 20% in the gel phase and 10% in the fluid phase. the effects of protease on the surface pressure of monolayers composed by dioleoylphosphatidylcholine (dopc), dimyristoylphosphatidylcholine (dmpc), dimyristoyl phosphatidylethanolamine (dmpe) we ...	2003	12598050
lipase-catalyzed interesterification of soybean oil with an omega-3 polyunsaturated fatty acid concentrate prepared from sardine oil.	to reduce the content of linoleoyl moiety in soybean oil, soybean oil that contains 53.0% linoleoyl moiety as molar acyl moiety composition was interesterified with an omega-3 polyunsaturated fatty acid (pufa) concentrate (24.0 mol% eicosapentaenoic acid [epa], 40.4 mol% docosahexaenoic acid [dha]) prepared from sardine oil, using an immobilized sn-1,3-specific lipase from rhizomucor miehei (lipozyme im). the reaction was carried out in a batch reactor at 37 degrees c under the following conditi ...	2003	12603099
synthesis of ethyl isovalerate using rhizomucor miehei lipase: optimization.	immobilized lipase from rhizomucor miehei (lipozyme im-20) was used to catalyze the esterification reaction between isovaleric acid and ethanol to synthesize ethyl isovalerate in n-hexane. response surface methodology based on five-level four-variable central composite rotatable design was employed to optimize four important reaction variables such as enzyme/substrate e/s ratio, substrate concentration, incubation time, and temperature affecting the synthesis of ethyl isovalerate. the optimum co ...	2003	12754824
optimization of lipase-catalyzed biodiesel by response surface methodology.	biodiesel prepared by catalyzed mild transesterification has become of much current interest for bioenergy. the ability of a commercial immobilized lipase (novo industries--bagsvaerd, denmark) from rhizomucor miehei (lipozyme im-77) to catalyze the transesterification of soybean oil and methanol was investigated in this study. response surface methodology and 5-level-5-factor central composite rotatable design were employed to evaluate the effects on reaction time, temperature, enzyme amount, mo ...	2003	12576002
lipase-mediated deacetylation and oligomerization of lactonic sophorolipids.	the direct enzymatic polymerization of lactonic sophorolipids (sls) was investigated with four lipases, including porcine pancreatic lipase (ppl), immobilized mucor miehei lipase (mml), lyophilized candida antarctica lipase (fraction b, cal-b), and lyophilized pseudomonas sp. lipase (psl). several organic solvents, covering a wide range of polarity, were compared for suitability as the reaction medium. isopropyl ether and toluene were found most effective. according to the quantification and str ...	2003	12675564
effects of temperature and pressure on rhizomucor miehei lipase stability.	both high temperature and high hydrostatic pressure induce irreversible deactivation of enzymes. they enable the enzyme's thermodynamic parameters to be determined and are used to study the mechanisms involved in biochemical systems. the effect of these two factors on the stability of rhizomucor miehei lipase have been investigated. the stability criterion used was residual hydrolytic activity of the lipase. experimental and theoretical parameters, obtained by linear regression analysis, were co ...	2003	12668311
cloning of an alkaline lipase gene from penicillium cyclopium and its expression in escherichia coli.	the gene encoding an alkaline lipase of penicillium cyclopium pg37 was cloned with four steps of pcr amplification based on different principles. the cloned gene was 1,480 nucleotides in length, consisted of 94 bp of promoter region, and had 6 exons and 5 short introns ranging from 50 to 70 nucleotides. the open reading frame encoded a protein of 285 amino acid residues consisting of a 27-aa signal peptide and a 258-aa mature peptide, with a conserved motif of gly-x-ser-x-gly shared by all types ...	2003	12784858
transformation of mucor miehei results in plasmid deletion and phenotypic instability.	mucor miehei transformants resistant to geneticin have been obtained by treatment of protoplasts with different plasmids and by agrobacterium-mediated dna transfer. all transformants exhibited a very unstable phenotype whose maintenance required continuous selective pressure. molecular analysis of transformants showed that the plasmid dna was extensively modified and maintained in very low amount. our results indicate that m. miehei reluctance to transformation is due to different causes, includ ...	2003	12855175
[rennet production by rhizomucor miehei nrrl 3169].	the production of rennet was studied, using different strains of the fungus rhizomucor miehei. the selection and preservation of strains, type of growth, media design and operation conditions were evaluated. the experiments were carried out in erlenmeyer flasks in rotary shaker at 250 rpm and 2.5 eccentricity, and in mechanically stirred fermentors of the new brunswick type, at 30 degrees c. in the studies concerning strain selection, the best strain was rhizomucor miehei nrrl 3169. the major ti ...	2003	14587373
enzymatic synthesis of phosphocarnitine, phosphogabob and fosfomycin.	phosphocarnitine was conveniently obtained from easily available diethyl 3-chloro-2-oxopropanephosphonates, followed by subsequent reduction, mucor miehei lipase (im) mediated resolution, amination and dealkylation. candida antarctica lipase b (calb) served as an effective biocatalyst in the resolution of several 1- or 2-hydroxyalkanephosphonates. the chlorine atom in different positions on the molecules greatly affected their enantioselectivity. calb also showed satisfactory enantioselectivity ...	2003	14599018
phylogenetic relationship of the genus gilbertella and related genera within the order mucorales based on 5.8 s ribosomal dna sequences.	the complete its (internal transcribed spacer) region coding the its1, the its2 and the 5.8s rdna was amplified by polymerase chain reaction from two strains of gilbertella persicaria, six strains in the mucoraceae (mucor piriformis, m. rouxii, m. circinelloides, rhizomucor miehei, r. pusillus and r. tauricus) and four strains representing three species of the choanephoraceae (blakeslea trispora, choanephora infundibulifera and poitrasia circinans). sequences of the amplified dna fragments were ...	2003	14711043
hyperactivation of rhizomucor miehei lipase by hydrophobic xerogels.	although a variety of approaches exist for the immobilization of enzymes, the "science" of enzyme immobilization is still in its infancy. in recent years, considerable interest has developed regarding the use of xerogels for enzyme immobilization. there are several advantages to xerogels for enzyme immobilization, including the opportunity to produce them in defined shapes or thin films and the ability to manipulate their physical characteristics (e.g., porosity, hydrophobicity, and optical prop ...	2004	14966806
reversible and strong immobilization of proteins by ionic exchange on supports coated with sulfate-dextran.	new and strong ionic exchange resins have been prepared by the simple and rapid ionic adsorption of anionic polymers (sulfate-dextran) on porous supports activated with the opposite ionic group (deae/manae). ionic exchange properties of such composites were strongly dependent on the size of the ionic polymers as well as on the conditions of the ionic coating of the solids with the ionic polymers (optimal conditions were 400 mg of sulfate-dextran 5000 kda per gram of support). around 80% of the p ...	2004	15296440
mono-thioesters and di-thioesters by lipase-catalyzed reactions of alpha,omega-alkanedithiols with palmitic acid or its methyl ester.	1- s-mono-palmitoyl-hexanedithiol and 1- s-mono-palmitoyl-octanedithiol were prepared in high yield (80-90%) by solvent-free lipase-catalyzed thioesterification of palmitic acid with the corresponding alpha,omega-alkanedithiols in vacuo. similarly, 1,6-di- s-palmitoyl-hexanedithiol and 1,8-di- s-palmitoyl-octanedithiol were prepared in moderate yield (50-60%) by solvent-free lipase-catalyzed thioesterification of palmitic acid with 1- s-mono-palmitoyl-hexanedithiol and 1- s-mono-palmitoyl-octane ...	2004	15048592
a novel hydrophilic support, cofoam, for enzyme immobilization.	lipases from different sources (porcine pancreas, mucor miehei and candida antarctica b) were covalently immobilized on a hydrophilic polyurethane composite (cofoam). their hydrolytic activities assayed with tributyrin were 0.55, 2.1 and 447 u g(-1), respectively. the activity of the c. antarctica b composite in the synthesis of methyl oleate in hexane was 8.8 u g(-1) compared to 60.6 u g(-1) for commercial novozyme 435. the advantage of the cofoam composite lies in the low pressure drop in a pa ...	2004	15127787