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combination of site-directed mutagenesis and yeast surface display enhances rhizomucor miehei lipase esterification activity in organic solvent.to increase the activity of rhizomucor miehei lipase (rml) in organic solvent, multiple sequence alignments and rational site-directed mutagenesis were used to create rml variants. the obtained proteins were surface-displayed on pichia pastoris by fusion to flo1p as an anchor protein. the synthetic activity of four variants showed from 1.1- to 5-fold the activity of native lipase in an esterification reaction in heptane with alcohol and caproic acid as substrates. the increase in esterification ...201121809089
psop1, a milk-clotting aspartic peptidase from the basidiomycete fungus piptoporus soloniensis.the first enzyme of the basidiomycete piptoporus soloniensis, a peptidase (psop1), was characterized after isolation from submerged cultures, purification by fractional precipitation, and preparative native-polyarylamide gel electrophoresis (page). the native molecular mass of psop1 was 38 kda with an isoelectric point of 3.9. similar to chymosin from milk calves, psop1 showed a maximum milk-clotting activity (mca) at 35-40 °c and was most stable at ph 6 and below 40 °c. the complete inhibition ...201121888369
use of lipase from rhizomucor miehei in dry fermented sausages elaboration: microbial, chemical and sensory analysis.three different amounts of lipase (0.075, 0.100 and 0.150 lu/g) from rhizomucor miehei (palatase m 200l novo nordisk) were used to determine the correct amount to use in dry fermented sausages. determination of acidity values through fourteen days of ripening showed that 0.100 lu/g was the most appropriate. two types of fermented sausages were manufactured, addition of the enzyme being the only difference between them. addition of palatase did not affect product stability (ph and a(w)), and the ...199722061141
enzymatically catalyzed synthesis of low-calorie structured lipid in a solvent-free system: optimization by response surface methodology.a kind of low-calorie structured lipid (lcsl) was obtained by interesterification of tributyrin (tb) and methyl stearate (st-me), catalyzed by a commercially immobilized 1,3-specific lipase, lipozyme rm im from rhizomucor miehei . the condition optimization of the process was conducted by using response surface methodology (rsm). the optimal conditions for highest conversion of st-me and lowest content lll-tag (sss and ssp; s, stearic acid; p, palmitic acid) were determined to be a reaction tim ...201122082136
hydrolysis of triacetin catalyzed by immobilized lipases: effect of the immobilization protocol and experimental conditions on diacetin yield.the effect of the immobilization protocol and some experimental conditions (ph value and presence of acetonitrile) on the regioselective hydrolysis of triacetin to diacetin catalyzed by lipases has been studied. lipase b from candida antarctica (calb) and lipase from rhizomucor miehei (rml) were immobilized on sepabeads (commercial available macroporous acrylic supports) activated with glutaraldehyde (covalent immobilization) or octadecyl groups (adsorption via interfacial activation). all the b ...201122113024
Studies of Reaction Variables for Lipase-Catalyzed Production of Alpha-Linolenic Acid Enriched Structured Lipid and Oxidative Stability with Antioxidants. Alpha-linolenic acid (ALA) enriched structured lipid (SL) was produced by lipase-catalyzed interesterification from perilla oil (PO) and corn oil (CO). The effects of different reaction conditions (substrate molar ratio [PO/CO 1:1 to 1:3], reaction time [0 to 24 h], and reaction temperature [55 to 65 °C]) were studied. Lipozyme RM IM from Rhizomucor miehei was used as biocatalyst. We obtained 32.39% of ALA in SL obtained under the optimized conditions (molar ratio-1:1 [PO:CO], temperature-60 ° ...201122122200
nonthermal effect of microwave irradiation in nonaqueous enzymatic esterification.microwave has nonthermal effects on enzymatic reactions, mainly caused by the polarities of the solvents and substrates. in this experiment, a model reaction with caprylic acid and butanol that was catalyzed by lipase from mucor miehei in alkanes or arenes was employed to investigate the nonthermal effect in nonaqueous enzymatic esterification. with the comparison of the esterification carried by conventional heating and consecutive microwave irradiation, the positive nonthermal effect on the in ...201222262019
internal ribosome entry site mediates protein synthesis in yeast pichia pastoris.the imitation of translation, as mediated by internal ribosome entry sites, has not yet been reported in pichia pastoris. an ires element from saccharomyces cerevisiae was demonstrated to direct the translation of a dicistronic mrna in p. pastoris. the 5′-untranslated region of gpr1 mrna, termed gpr, was cloned into a dual reporter construct containing an upstream rhizomucor miehei lipase (rml) and a downstream β-galactosidase gene (lacz) from escherichia coli bl21. after being transformed into ...201222286182
cloning and sequence analysis of complete gene encoding an alkaline lipase from penicillium cyclopium.the complete gene (pg37 lipi) encoding an alkaline lipase (pg37 lipi) was cloned from the genomic dna of penicillium cyclopium pg37. the cloned pg37 lipi is 2020 bp in length, consisting of 632 bp of the 5' flanking promoter region and 1388 bp of the downstream fragment that contains 6 exons and 5 short introns. the promoter region harbors putative tata box, caat box and several transcription factor binding sites. the open reading frame (orf) encodes a pg37 lipi of 285 amino acid residues, which ...201122288192
purification and characterization of a novel β-1,3-1,4-glucanase (lichenase) from thermophilic rhizomucor miehei with high specific activity and its gene sequence.production, purification, and characterization of a novel β-1,3-1,4-glucanase (lichenase) from thermophilic rhizomucor miehei cau432 were investigated. high-level extracellular β-1,3-1,4-glucanase production of 6230 u/ml was obtained when oat flour (3%, w/v) was used as a carbon source at 50 °c. the crude enzyme was purified to homogeneity with a specific activity of 28818 u/mg. the molecular weight of purified enzyme was estimated to be 35.4 kda and 33.7 kda by sds-page and gel filtration, resp ...201222309761
characterization of a protease-resistant α-galactosidase from the thermophilic fungus rhizomucor miehei and its application in removal of raffinose family oligosaccharides.the α-galactosidase gene, rmgal36, from rhizomucor miehei was cloned and expressed in escherichia coli. the gene has an open reading frame of 2256bp encoding 751 amino acid residues. rmgal36 was optimally active at ph 4.5 and 60°c, but is stable between ph 4.5 and 10.0 and at a temperature of up to 55°c for 30min retaining more than 80% of its relative activity. it displayed remarkable resistance to proteases and its activity was not inhibited by galactose concentrations of 100mm. the relative s ...201222349190
use of mucor miehei lipase to improve functional properties of yolk-contaminated egg whites.egg yolk contamination of egg whites continues to be a serious problem in the egg industry. the ability of egg whites to form stable and voluminous foams is greatly inhibited by yolk contamination, even at very low levels, between 0.01% and 0.2% w/w yolk in white. experiments were conducted to determine if mucor miehei lipase could regenerate the functional properties of yolk-contaminated egg whites. lipase from m. miehei and colipase from porcine pancreas were added to yolk-contaminated (0.2%, ...201122417349
structure elucidation of a new natural diketopiperazine from a microbispora aerata strain isolated from livingston island, antarctica.a new natural diketopiperazine (1) was obtained from the culture broth of microbispora aerata strain imbas-11a, isolated from penguin excrements collected on the antarctic livingston island. compound 1 was purified consecutively by solvent extraction, silica gel column chromatography and preparative hplc. the structure of the compound was elucidated by 1d and 2d nmr experiments and mass spectrometric investigations. the absolute configuration of compound 1 was determined by amino acid analysis a ...201322420410
study of new feruloyl esterases to understand lipase evolution: the case of bacillus flexus.recently, the crystal structure of the feruloyl esterase a from aspergillus niger (anfaea) was elucidated. this enzyme displays an α/β hydrolase fold and a catalytic triad similar to that found in fungal lipases (30-37% identity). surprisingly, anfaea showed an overall fold similarity with the rhizomucor miehei and other related fungal lipases. all these data strongly suggest that the ancestral function (lipase) had shifted, with molecular adaptation leading to a novel enzyme (type-a feruloyl es ...201222426711
characterization of a β-glucosidase with transgalactosylation capacity from the zygomycete rhizomucor miehei.an extracellular β-glucosidase from the zygomycete rhizomucor miehei nrrl 5282 cultivated in a wheat bran-based solid state fermentation system was characterized. the purified enzyme exhibited an optimum temperature of 68-70 °c and ph of 5.0. it efficiently hydrolyzed oligosaccharides having β-(1→4) glycosidic linkages and exhibited some β- and α-galactosidase activity. the v(max) for p-nitrophenyl-β-d-glucopyranoside and cellobiose was 468.2 and 115.5 u/mg, respectively, while the k(m) was 0.12 ...201222444635
high-throughput screening of b factor saturation mutated rhizomucor miehei lipase thermostability based on synthetic reaction.conventional lipase screening methods are mostly based on hydrolytic activity, which may not always be the best method to assess the enzyme activity, especially for evaluating synthetic activity. here we developed a high throughput and visual method to screen clones with high synthetic activity and used it to assess lipases thermostability. all mutants' lipase synthetic activity were identified through esterification of caprylic acid and ethanol with methyl red as the ph indicator adding in the ...201222500900
optimization of reaction conditions for enzymatic synthesis of palm fatty hydrazides using response surface methodology.optimization of the enzymatic synthesis of palm fatty hydrazide by the response surface methodology (rsm) was conducted using the design-expert 6 software. the palm fatty hydrazide was synthesized from refined, bleached and deodorized palm olein (rbdpoo) and neutralized hydrazine monohydrate in the presence of rhizomucor miehei lipase, lipozyme rmim, an immobilized lipase in n-hexane. the reaction conditions such as the percentage of enzyme, reaction temperature, stirring speed and reaction time ...201222531058
enhanced activity of rhizomucor miehei lipase by directed evolution with simultaneous evolution of the propeptide.propeptides are short sequences that facilitate the folding of their associated proteins. the present study found that the propeptide of rhizomucor miehei lipase (rml) was not proteolytically removed in escherichia coli. moreover, rml was not expressed if the propeptide was removed artificially during the cloning process in e. coli. this behavior in e. coli permitted the application of directed evolution to full-length rml, which included both propeptide and catalytic domain, to explore the role ...201222584429
purification and characterization of an extracellular lipase from mucor hiemalis f. corticola isolated from soil.we have screened 39 microfungi isolates originated from soil in terms of lipolytic activity. out of all screened, a novel strain of mucor hiemalis f. corticola was determined to have the highest lipase activity. the extracellular lipase was produced in response to 2% glucose and 2.1% peptone. the lipase was purified 12.63-folds with a final yield of 27.7% through following purification steps; ammonium sulfate precipitation, dialysis, gel filtration column chromatography and ion exchange chromato ...201222652088
immobilization of lipase from mucor miehei and rhizopus oryzae into mesoporous silica--the effect of varied particle size and morphology.immobilization of enzymes usually improves the recyclability and stability and can sometimes also improve the activity compared to enzymes free in solution. mesoporous silica is a widely studied material as host for immobilized enzymes because of its large internal surface area and tunable pores. it has previously been shown that the pore size is critical both for the loading capacity and for the enzymatic activity; however, less focus has been given to the influence of the particle size. in thi ...201222750108
tandem transformation of glycerol to esters.tandem transformation of glycerol via microbial fermentation and enzymatic esterification is presented. the reaction can be performed with purified waste glycerol from biodiesel production in a continuous mode, combining continuous fermentation with membrane-supported enzymatic esterification. continuous anaerobic fermentation was optimized resulting in the productivity of 2.4 g l⁻¹ h⁻¹ of 1,3-propanediol. biphasic esterification of 1,3-propanediol was optimized to achieve ester yield of up to 7 ...201222796408
application of chemoenzymatic hydrolysis in the synthesis of 2-monoacylglycerols.the selective biocatalyzed synthesis of 2-monoacylglycerols (2-mags) through the use of commercially available immobilized candida antarctica (novozym435) and rhizomucor miehei is explored. reactions at room temperature result in the formation of a 2-mag and a corresponding ethyl ester of the fatty acid with immobilized candida antarctica within 2h with yields ranging from 36%-83%. similar reaction conditions with immobilized rhizomucor miehei yielded exclusively the 2-mag after 24h with yields ...201222822273
lipase-catalyzed preparation of diacylglycerol-enriched oil from high-acid rice bran oil in solvent-free system.the ability of immobilized lipase from rhizomucor miehei (lipozyme rm im) to catalyze the reaction of high-acid rice bran oil (rbo) and monoglyceride (mg) for diacylglycerol-enriched rice bran oil (rbo-dg) preparation was investigated. the effects of substrate ratio, reaction temperature, time, and enzyme load on the respective content of free fatty acid (ffa) and dg in the final rbo-dg products was investigated. enzyme screening on the reaction was also investigated. response surface methodolog ...201222948601
hydrolysis of virgin coconut oil using immobilized lipase in a batch reactor.hydrolysis of virgin coconut oil (vco) had been carried out by using an immobilised lipase from mucor miehei (lipozyme) in a water-jacketed batch reactor. the kinetic of the hydrolysis was investigated by varying the parameters such as vco concentration, enzyme loading, water content, and reaction temperature. it was found that vco exhibited substrate inhibition at the concentration more than 40% (v/v). lipozyme also achieved the highest production of free fatty acids, 4.56 mm at 1% (w/v) of enz ...201222953055
a simple method for positional analysis of phosphatidylcholine.simple and fast method of positional analysis of fatty acid composition of phosphatidylcholine (pc) from egg-yolk and soy has been elaborated. the key step of the procedure was complete ethanolysis of pc catalyzed by sn-1,3 specific lipase from mucor miehei (lipozyme). 2-acyl-lysophosphatidylcholine (2-acyl lpc), fatty acids ethyl esters (faees) and free fatty acids (fas) were formed in this process. no acyl migration was observed during the reaction. the products were entirely separated from th ...201222980840
depigmenting effect of kojic acid esters in hyperpigmented b16f1 melanoma cells.the depigmenting effect of kojic acid esters synthesized by the esterification of kojic acid using rhizomucor miehei immobilized lipase was investigated in b16f1 melanoma cells. the depigmenting effect of kojic acid and kojic acid esters was evaluated by the inhibitory effect of melanin formation and tyrosinase activity on alpha-stimulating hormone- (α-msh-) induced melanin synthesis in b16f1 melanoma cells. the cellular tyrosinase inhibitory effect of kojic acid monooleate, kojic acid monolaura ...201223091364
high yield of wax ester synthesized from cetyl alcohol and octanoic acid by lipozyme rmim and novozym 435.wax esters are long-chain esters that have been widely applied in premium lubricants, parting agents, antifoaming agents and cosmetics. in this study, the biocatalytic preparation of a specific wax ester, cetyl octanoate, is performed in n-hexane using two commercial immobilized lipases, i.e., lipozyme(®) rmim (rhizomucor miehei) and novozym(®) 435 (candida antarctica). response surface methodology (rsm) and 5-level-4-factor central composite rotatable design (ccrd) are employed to evaluate the ...201223109878
in vitro interactions of amantadine hydrochloride, r-(-)-deprenyl hydrochloride and valproic acid sodium salt with antifungal agents against filamentous fungal species causing central nervous system infection.the mortality rates of fungal infections that affect the central nervous system are high in consequence of the absence of effective antifungal drugs with good penetration across the blood-brain barrier and the blood-cerebrospinal fluid barrier. in the present work in vitro antifungal activities of three good penetrating non-antifungal drugs (amantadine hydrochloride, r-(-)-deprenyl hydrochloride, valproic acid sodium salt) and their combinations with three antifungal agents (amphotericin b, itra ...201223134606
gene cloning and enzymatic characterization of an alkali-tolerant endo-1,4-β-mannanase from rhizomucor miehei.an endo-1,4-β-mannanase gene (rmman5a) was cloned from the thermophilic fungus rhizomucor miehei for the first time and expressed in escherichia coli . the gene had an open reading frame of 1330 bp encoding 378 amino acids and contained four introns. it displayed the highest amino acid sequence identity (42%) with the endo-1,4-β-mannanases from glycoside hydrolase family 5. the purified enzyme was a monomer of 43 kda. rmman5a displayed maximum activity at 55 °c and an optimal ph of 7.0. it was t ...201323252695
combined utilization of lipase-displaying pichia pastoris whole-cell biocatalysts to improve biodiesel production in co-solvent media.lipase-displaying whole cells appear to be efficient biocatalysts because of their low preparation costs and simple recycling procedure. the combined utilization of candida antarctica lipase b (calb) and rhizomucor miehei lipase (rml), separately displayed on pichia pastoris whole cells, to produce biodiesel in co-solvent media was investigated. a response surface methodology incorporating a d-optimal design was employed to obtain the optimum reaction conditions for methyl ester (me) synthesis. ...201223306117
characterization of two novel family 12 xyloglucanases from the thermophilic rhizomucor miehei.two novel glycoside hydrolase (gh) family 12 xyloglucanase genes (designated rmxeg12a and rmxeg12b) were cloned from the thermophilic fungus rhizomucor miehei. both genes contained open reading frames of 729 bp encoding 242 amino acids. their deduced amino acid sequences shared 68% identity with each other and less than 60% with other xyloglucanases. the two genes, without the sequences for the signal peptides, were cloned and successfully expressed in escherichia coli as active xyloglucanases, ...201323463247
investigations on diffusion limitations of biocatalyzed reactions in amphiphilic polymer conetworks in organic solvents.the use of enzymes as biocatalysts in organic media is an important issue in modern white biotechnology. however, their low activity and stability in those media often limits their full-scale application. amphiphilic polymer conetworks (apcns) have been shown to greatly activate entrapped enzymes in organic solvents. since these nanostructured materials are not porous, the bioactivity of the conetworks is strongly limited by diffusion of substrate and product. the present manuscript describes tw ...201323532873
enzymatic interesterification of a lard and rapeseed oil equal-weight blend.a mixture of lard and rapeseed oil (1:1, wt/wt) was interesterified using immobilized lipases from rhizomucor miehei (lipozyme rm im) and candida antarctica (novozym 435) as catalysts. enzymatic interesterifications were carried out at 60°c for 8 h with lipozyme rm im or at 80°c for 4 h with novozym 435. the biocatalyst doses were kept constant (8 wt-%). the starting blend was quantitatively separated by column chromatography into pure triacylglycerol fraction (98.5%), and a nontriacylglycerol f ...201323535304
incorporation of omega-3 polyunsaturated fatty acids into soybean lecithin: effect of amines and divalent cations on transesterification by lipases.the transesterification of soybean lecithin with methyl esters of epa and dha in an organic solvent (hexane) using various commercially available lipases was studied. lipases produced by candida antarctica, pseudomonas fluorescens, burkholderia cepacia, mucor miehei, thermomyces lanuginosus and rhizomucor miehei were compared, in the absence or presence of histidine, arginine, urea, ca²⁺, mg²⁺, or a combination of urea and divalent cations (additives at 5 % of the total lipid mass). transesterif ...201323749246
biotransformation of oleanolic and maslinic acids by rhizomucor miehei.microbial transformation of oleanolic acid by rhizomucor miehei produced three metabolites. a known compound, a 30-hydroxyl derivative (queretaroic acid), and two 7β,30- and 1β,30-dihydroxylated metabolites, respectively. the action of the same fungus (r. miehei) on maslinic acid produced an olean-11-en-28,13β-olide derivative, a metabolite hydroxylated at c-30, an 11-oxo derivative, and two metabolites with an 11α,12α-epoxy group, hydroxylated or not at c-30. their structures were elucidated by ...201323790643
structure-guided modification of rhizomucor miehei lipase for production of structured lipids.to improve the performance of yeast surface-displayed rhizomucor miehei lipase (rml) in the production of human milk fat substitute (hmfs), we mutated amino acids in the lipase substrate-binding pocket based on protein hydrophobicity, to improve esterification activity. five mutants: asn87ile, asn87ile/asp91val, his108leu/lys109ile, asp256ile/his257leu, and his108leu/lys109ile/asp256ile/his257leu were obtained and their hydrolytic and esterification activities were assayed. using discovery studi ...201323844120
synthesis of ascorbyl oleate by transesterification of olive oil with ascorbic acid in polar organic media catalyzed by immobilized lipases.the reaction of transesterification between oils (e.g., olive oil) and ascorbic acid in polar anhydrous media (e.g., tert-amyl alcohol) catalyzed by immobilized lipases for the preparation of natural liposoluble antioxidants (e.g., ascorbyl oleate) was studied. three commercial lipases were tested: candida antarctica b lipase (calb), thermomyces lanuginosus lipase (tll) and rhizomucor miehei lipase (rml). each lipase was immobilized by three different protocols: hydrophobic adsorption, anionic e ...201323891831
oligomerization of 10,16-dihydroxyhexadecanoic acid and methyl 10,16-dihydroxyhexadecanoate catalyzed by lipases.the main monomer of tomato cuticle, 10,16-dihydroxyhexadecanoic acid (10,16-dhpa) and its methyl ester derivative (methyl-10,16-dihydroxyhexadecanote; methyl-10,16-dhhd), were used to study their oligomerization reactions catalyzed by five lipases: candida antarctica lipase b (cal-b), rhizomucor miehei lipase (rm), thermomyces lanuginosus lipase (tl), pseudomonas cepacia lipase (pcl) and porcine pancreatic lipase (ppl). for 10,16-dhpa, optimum yields were obtained at 60 °c using toluene and 2-me ...201323921794
isocyanate-mediated covalent immobilization of mucor miehei lipase onto sba-15 for transesterification reaction.mucor miehei lipase (mm-l) covalently bind on a hexagonally ordered silica sba-15 (santa barbara amorphous), previously functionalized with isocyanate moieties, was examined as biocatalyst for transesterification of colza oil with methanol. the isocyanate-mesoporous silica (nco-sba-15) was obtained by condensation of silanol with triethoxysilane propyl isocyanate (tpi). the efficiency of the functionalization has been evidenced by infrared, (29)si and (13)c nmr spectroscopies. the substrate prov ...201323973672
one-pot lipase-catalyzed aldol reaction combination of in situ formed acetaldehyde.a facile tandem route to α,β-unsaturated aldehydes was developed by combining the two catalytic activities of the same enzyme in a one-pot strategy for the aldol reaction and in situ generation of acetaldehyde. lipase from mucor miehei was found to have conventional and promiscuous catalytic activities for the hydrolysis of vinyl acetate and aldol condensation with in situ formed acetaldehyde. the first reaction continuously provided material for the second reaction, which effectively reduced th ...201323975282
identification, isolation and optimization of antifungal metabolites from the streptomyces malachitofuscus ctf9.an indigenous streptomyces isolate ctf9, exhibiting promising antifungal activity against mucor miehei and candida albicans in pre-screening studies, was investigated by cultivation in a 50-l fermenter and by subsequent isolation, purification, and structure elucidation of the active metabolites. based on the morphological, biochemical, and physiological characterization, as well as the 16s rrna gene sequence, the isolate ctf9 was identified as streptomyces malachitofuscus. using a series of chr ...201124031671
enhanced activity of rhizomucor miehei lipase by deglycosylation of its propeptide in pichia pastoris.many studies have demonstrated that the properties of enzymes expressed in eukaryotes can be affected by the position and extent of glycosylation on enzyme. in this study, two potential glycosylation sites (the 8th and the 58th asparagine) were identified and the effect of propeptide glycosylation on rhizomucor miehei lipase (rml) expressed in pichia pastoris was investigated. to better understand the effect of glycosylation on the activity of rml, three mutants (m1, generated by n8a; m2, genera ...201424068111
the structure of a glycoside hydrolase family 81 endo-β-1,3-glucanase.endo-β-1,3-glucanases catalyze the hydrolysis of β-1,3-glycosidic linkages in glucans. they are also responsible for rather diverse physiological functions such as carbon utilization, cell-wall organization and pathogen defence. glycoside hydrolase (gh) family 81 mainly consists of β-1,3-glucanases from fungi, higher plants and bacteria. a novel gh family 81 β-1,3-glucanase gene (rmlam81a) from rhizomucor miehei was expressed in escherichia coli. purified rmlam81a was crystallized and the struct ...201324100321
properties and oxidative stabilities of enzymatically interesterified chicken fat and sunflower oil blend.chicken fat and sunflower oil 2:3 m/m blend was enzymatically interesterified at 60°c with and without microwaves assistance. as the catalyst a commercial preparation of the immobilized lipase from rhizomucor miehei (lipozyme rm im) containing 2% of water was used, and the catalyst load was 8% in each case. the starting mixture and the interesterified products were separated by column chromatography into pure triacylglycerols fraction (tag) and a non-triacylglycerol fraction, which contained fre ...201324200936
biochemical characterization of a first fungal esterase from rhizomucor miehei showing high efficiency of ester synthesis.esterases with excellent merits suitable for commercial use in ester production field are still insufficient. the aim of this research is to advance our understanding by seeking for more unusual esterases and revealing their characterizations for ester synthesis.201324204998
preparation of triacylglycerols rich in omega-3 fatty acids from sardine oil using a rhizomucor miehei lipase: focus in the epa/dha ratio.the increasing evidence on the differential biochemical effects of eicosapentaenoic acid (epa)/docosahexaenoic acid (dha) raises the need of n-3 highly unsaturated fatty acid concentrates with different amounts of these fatty acids. in the present work, physicochemical and enzymatic techniques were combined to obtain acylglycerols, mainly triacylglycerols (tag), rich in n-3 fatty acids. sardine oil was obtained by washing sardine (sardina pilchardus) mince with a nahco3 solution, hydrolyzed in a ...201424293255
biochemical characterization of a novel l-asparaginase with low glutaminase activity from rhizomucor miehei and its application in food safety and leukemia treatment.a novel fungal gene encoding the rhizomucor miehei l-asparaginase (rmasnase) was cloned and expressed in escherichia coli. its deduced amino acid sequence shared only 57% identity with the amino acid sequences of other reported l-asparaginases. the purified l-asparaginase homodimer had a molecular mass of 133.7 kda, a high specific activity of 1,985 u/mg, and very low glutaminase activity. rmasnase was optimally active at ph 7.0 and 45°c and was stable at this temperature for 30 min. the final l ...201424362429
oxidation behavior of triacylglycerol containing conjugated linolenic acids in sn-1(3) or sn-2 position.the location of unsaturated fatty acid in triacylglycerols (tags) affects their oxidative stability. herein, we studied the effect of location of conjugated linolenic acids (clns) in tags on their oxidative stability. first, the tags containing clns at sn-1(3) and sn-2 positions, were enzymatically prepared via lipozyme rm-im (immobilized rhizomucor miehei lipase)-mediated acidolysis- and contained ca. 60% of clns at sn-1(3) or sn-2 position. the auto-oxidation test at 30°c in the dark showed ox ...201424371198
in vivo and in vitro evaluation of octyl methoxycinnamate liposomes.solar radiation causes damage to human skin, and photoprotection is the main way to prevent these harmful effects. the development of sunscreen formulations containing nanosystems is of great interest in the pharmaceutical and cosmetic industries because of the many potential benefits. this study aimed to develop and evaluate an octyl methoxycinnamate (omc) liposomal nanosystem (liposome/omc) to obtain a sunscreen formulation with improved safety and efficacy by retaining omc for longer on the s ...201324376350
growth of three fungi on poultry fat or beef tallow.aspergillus niger, geotrichum candidum and mucor miehei, when grown on a medium containing beef tallow or poultry fat for 5 days at 28°c, in roux bottles, shake-flasks or fermenters, synthesized from 0.4 to 3.2 g lipids/i. the degree of fat utilization varied from 15 to 70%. the type of fat in the medium, the species of fungi and its cultivation method all influenced the fatty acid composition of fats remaining in the medium, as well as the intracellular lipids of the fungi.199324420293
influence of culture conditions on the production of milk-clotting enzyme from rhizomucor.the ratio of milk-clotting activity to proteolytic activity (mc/pa) was used as an index to determine the quality of milk-clotting enzyme. solid-state fermentation on wheat bran for 5 days at room temperature gave optimal production for enzyme by rhizomucor miehei and r. pusillus. a ratio of wheat bran to moisture of 1:0.6 (w/v) gave best results. adding skim milk powder to the media of r. miehei did not improve the mc/pa ratio but 4% (w/w) of the powder did improve the ratio with r. pusillus. c ...199424421126
selective ethanolysis of sunflower oil with lipozyme rm im, an immobilized rhizomucor miehei lipase, to obtain a biodiesel-like biofuel, which avoids glycerol production through the monoglyceride formation.the obtaining of ecodiesel, a biofuel applicable to diesel engines which keeps the glycerin as monoglyceride (mg), was achieved through a selective ethanolysis process of sunflower oil, by application of lipozyme rm im, a rhizomucor miehei lipase immobilized on macroporous anion exchange resins. this biocatalyst that was already described in the synthesis of conventional biodiesel has also shown its efficiency in the present selective enzymatic process, after optimization of the influence of var ...201424594272
conversion of a rhizopus chinensis lipase into an esterase by lid swapping.in an effort to explore the feasibility of converting a lipase into an esterase by modifying the lid region, we designed and characterized two novel rhizopus chinensis lipase variants by lid swapping. the substrate specificity of an r. chinensis lipase was successfully modified toward water-soluble substrates, that is, turned into an esterase, by replacing the hydrophobic lid with a hydrophilic lid from ferulic acid esterase from aspergillus niger meanwhile, as a comparison, the lid of r. chinen ...201424670990
lipase-catalyzed kinetic resolution of (±)-1-(2-furyl) ethanol in nonaqueous media.s-1-(2-furyl) ethanol serves as an important chiral building block for the preparation of various natural products, fine chemicals, and is widely used in the chemical and pharmaceutical industries. in this work, lipase-catalyzed kinetic resolution of (r/s)-1-(2-furyl) ethanol using different acyl donors was investigated. vinyl esters are good acyl donors vis-à-vis alkyl esters for kinetic resolution. among them, vinyl acetate was found to be the best acyl donor. different immobilized lipases suc ...201424733779
genome sequence and transcriptome analyses of the thermophilic zygomycete fungus rhizomucor miehei.the zygomycete fungi like rhizomucor miehei have been extensively exploited for the production of various enzymes. as a thermophilic fungus, r. miehei is capable of growing at temperatures that approach the upper limits for all eukaryotes. to date, over hundreds of fungal genomes are publicly available. however, zygomycetes have been rarely investigated both genetically and genomically.201424746234
gene cloning, functional expression and characterisation of a novel glycogen branching enzyme from rhizomucor miehei and its application in wheat breadmaking.a gene (rmgbe) encoding a glycogen branching enzyme from rhizomucor miehei was cloned into the pet28a (+) vector and expressed in escherichia coli, and biochemically analysed. rmgbe had an open reading frame of 2097bp encoding 698 amino acid residues. the purified enzyme was a monomer of 78.1kda. rmgbe was optimally active at 25°c and ph 7.5. it displayed excellent cold adaptation over a low temperature range of 10-30°c, retaining over 85% of its relative activity. rmgbe showed the highest speci ...201424767030
biochemical characterization of the first fungal glycoside hydrolyase family 3 β-n-acetylglucosaminidase from rhizomucor miehei.a novel β-n-acetylglucosaminidase gene (rmnag) from rhizomucor miehei was cloned and expressed in escherichia coli. rmnag shares the highest identity of 37% with a putative β-n-acetylglucosaminidase from aspergillus clavatus. the recombinant enzyme was purified to homogeneity. the optimal ph and temperature of rmnag were ph 6.5 and 50 °c, respectively. it was stable in the ph range 6.0-8.0 and at temperatures below 45 °c. rmnag exhibited strict substrate specificity for p-nitrophenyl β-n-acetylg ...201424811866
immobilization of mucor miehei lipase onto macroporous aminated polyethersulfone membrane for enzymatic reactions.immobilization of enzymes is one of the most promising methods in enzyme performance enhancement, including stability, recovery, and reusability. however, investigation of suitable solid support in enzyme immobilization is still a scientific challenge. polyethersulfone (pes) and aminated pes (pes-nh2) were successfully synthesized as novel materials for immobilization. membranes with various pore sizes (from 10-600 nm) based on synthesized pes and pes-nh2 polymers were successfully fabricated to ...201224958172
lipase catalyzed transesterification of castor oil by straight chain higher alcohols.biolubricants from castor oil were produced enzymatically by transesterification with higher alcohols using a lipase mixture of immobilized mucor miehei (rmim) and immobilized candida antarctica lipase b (novozym 435) under low water conditions. the conversions were in the range of 80-95% under the optimized conditions.201525204793
production of olive oil enriched with medium chain fatty acids catalysed by commercial immobilised lipases.structured triacylglycerols, containing medium chain fatty acids, were produced by acidolysis of virgin olive oil with caprylic or capric acid, at a molar ratio of olive oil:fatty acid of 1:2, at 45°c for 24h, in solvent-free media or in n-hexane, catalysed by thermomyces lanuginosa (lipozyme tl im), rhizomucor miehei (lipozyme rm im) and candida antarctica (novozym 435) immobilised lipases. incorporations were always greater for capric than for caprylic acid. for both acids, higher incorporatio ...201125214088
enzymatic esterification of free fatty acids in vegetable oils utilizing different immobilized lipases.different immobilized lipases were screened for their ability to esterify free fatty acids (ffa) with monoacylglycerol (mag) as acyl-group acceptor. a lipase from rhizomucor miehei (lipozyme rmim) was the most suitable for lipase-catalyzed de-acidification-a promising alternative to conventional neutralization. a reduction of the ffa content to 0.6 % (w/w) was achieved by applying a substrate with an initial ffa-content of 6 % (w/w), the reaction at 50 °c for 22 h as well as the stepwise additio ...201525214229
lipozyme rm im-catalyzed acidolysis of cinnamomum camphora seed oil with oleic acid to produce human milk fat substitutes enriched in medium-chain fatty acids.in the present study, a human milk fat substitute (hmfs) enriched in medium-chain fatty acids (mcfas) was synthesized through acidolysis reaction from cinnamomum camphora seed oil (ccso) with oleic acid in a solvent-free system. a commercial immobilized lipase, lipozyme rm im, from rhizomucor miehei, was facilitated as a biocatalyst. effects of different reaction conditions, including substrate molar ratio, enzyme concentration, reaction temperature, and reaction time were investigated using res ...201425298236
structural insights into the substrate specificity and transglycosylation activity of a fungal glycoside hydrolase family 5 β-mannosidase.β-mannosidases are exo-acting glycoside hydrolases (ghs) that catalyse the removal of the nonreducing end β-d-mannose from manno-oligosaccharides or mannoside-substituted molecules. they play important roles in fundamental biological processes and also have potential applications in various industries. in this study, the first fungal gh family 5 β-mannosidase (rmman5b) from rhizomucor miehei was functionally and structurally characterized. rmman5b exhibited a much higher activity against manno-o ...201425372687
impact of different deacidification methods on quality characteristics and composition of olein and stearin in crude red palm oil.crude red palm oil of 8.7% free fatty acid content was deacidified using enzyme (lipase from rhizomucor miehei), solvent (ethanol) and chemical (aqueous sodium hydroxide) and its impact on chemical characteristics and composition were evaluated. deacidification of oil using enzyme showed nearly 100% product yield. the neutral lipid loss after ethanol and sodium hydroxide deacidification of the oil was 13.6% and 19.5% respectively. the enzyme deacidified oil has shown a higher value in unsaponifi ...201425391686
high-level production of β-1,3-1,4-glucanase by rhizomucor miehei under solid-state fermentation and its potential application in the brewing industry.to improve the β-1,3-1,4-glucanase production by rhizomucor miehei under solid-state fermentation (ssf) for industrial application.201525393407
performance of structured lipids incorporating selected phenolic and ascorbic acids.conditions applied during frying require antioxidant which is stable at these conditions and provides protection for frying oil and fried food. novel structured lipids containing nutraceuticals and antioxidants were formed by enzymatic transesterification, exploring canola oil and naturally occurring antioxidants such as ascorbic and selected phenolic acids as substrates. lipozyme rm im lipase from rhizomucor miehei was used as biocatalyst. frying performance and oxidative stability of the final ...201525466089
an acidic, thermostable exochitinase with β-n-acetylglucosaminidase activity from paenibacillus barengoltzii converting chitin to n-acetyl glucosamine.n-acetyl-β-d-glucosamine (glcnac) is widely used as a valuable pharmacological agent and a functional food additive. the traditional chemical process for glcnac production has some problems such as high production cost, low yield, and acidic pollution. hence, to identify a novel chitinase that is suitable for bioconversion of chitin to glcnac is of great value.201425550712
recent patents on microbial proteases for the dairy industry.this paper reviews the general characteristics of exo and endopeptidases of microbial origin currently used in the milk industry. it also includes recent patents developed either to potentiate the enzymatic activity or to improve the resulting milk derivatives. the main application of these proteases is in the cheese-making industry. although this industry preferentially uses animal rennets, and in particular genetically engineered chymosins, it also utilizes milk coagulants of microbial origin. ...201425564028
expression and characterization of a novel β-glucosidase, with transglycosylation and exo-β-1,3-glucanase activities, from rhizomucor miehei.a novel β-glucosidase gene, designated rmbglu3b, was cloned from the thermophilic fungus, rhizomucor miehei cau432. its 2196-bp open reading frame encoded 731 amino acids. its deduced amino-acid sequence showed highest identity (66%) with a glycoside hydrolase family 3 β-glucosidase from r. miehei nrrl5382. rmbglu3b was successfully expressed in escherichia coli. the recombinant enzyme was purified to homogeneity with 18.2-fold purification and 59% recovery yield. molecular masses of 76.5 kda, b ...201525577102
biochemical characterization of a novel endo-1,5-α-l-arabinanase from rhizomucor miehei.a novel gene (designated as rmarase) encoding endo-1,5-α-l-arabinanase from a thermophilic fungus rhizomucor miehei was cloned and expressed in escherichia coli. the gene had an open reading frame (orf) of 930 base pairs (bp) encoding 309 amino acids. the amino acid sequence shared highest identity (56%) with a glycoside hydrolase (gh) family 43 endo-1,5-α-l-arabinase from bacillus subtilis and low identity (35%) with the endo-1,5-α-l-arabinase from aspergillus niger. the recombinant endo-1,5-α- ...201525582414
biodiesel production from microalgae oil catalyzed by a recombinant lipase.a recombinant rhizomucor miehei lipase was constructed and expressed in pichia pastoris. the target enzyme was termed lipase gh2 and it can be used as a free enzyme for catalytic conversion of microalgae oil mixed with methanol or ethanol for biodiesel production in an n-hexane solvent system. conversion rates of two major types of biodiesel, fatty acid methyl ester (fame) and fatty acid ethyl ester (faee), reached maximal values (>90%) after 24h. the process of fame production is generally more ...201525585254
modification and simulation of rhizomucor miehei lipase: the influence of surficial electrostatic interaction on enantioselectivity.surface residues have a significant impact on the enantioselectivity of lipases. but the molecular basis of this has never been explained. in this work, transition state complexes of rhizomucor miehei lipase (rml) and (r)- or (s)-n-butyl 2-phenxypropinate were studied using molecular dynamics. according to comparison between b-factor of the two simulated complexes, the β 1-β 2 loop and α 2 helix were considered the enantioselectivity-determining domains of rml. interaction analysis of these doma ...201525650338
high-level expression of a novel α-galactosidase gene from rhizomucor miehei in pichia pastoris and characterization of the recombinant enyzme.the second α-galactosidase gene (designated as rmgalb) was cloned from the thermophilic fungus rhizomucor miehei and expressed in pichia pastoris. the gene belonging to glycoside hydrolase (gh) family 36 has an open reading frame (orf) of 2241bp encoding 746 amino acids with two introns. the recombinant α-galactosidase (rmgalb) was secreted at high levels of 1953.9uml(-1) in high cell density fermentor, which is the highest yield obtained for a α-galactosidase. the purified enzyme as a tetramer ...201525712153
lysophosphatidylcholine synthesis by lipase-catalyzed ethanolysis.lysophosphatidylcholine (lpc) is amphiphilic substance, and possesses excellent physiological functions. in this study, lpc was prepared through ethanolysis of phosphatidylcholine (pc) in n-hexane or solvent free media catalyzed by novozym 435 (from candida antarctica), lipozyme tlim (from thermomcyces lanuginosus) and lipozyme rmim (from rhizomucor miehei). the results showed that three immobilized lipases from candida antarctica, thermomcyces lanuginosus and rhizomucor miehei could catalyze et ...201525766935
improved production of a recombinant rhizomucor miehei lipase expressed in pichia pastoris and its application for conversion of microalgae oil to biodiesel.we previously cloned a 1,3-specific lipase gene from the fungus rhizomucor miehei and expressed it in methylotrophic yeast pichia pastoris strain gs115. the enzyme produced (termed rml) was able to catalyze methanolysis of soybean oil and showed strong position specificity. however, the enzyme activity and amount of enzyme produced were not adequate for industrial application. our goal in the present study was to improve the enzyme properties of rml in order to apply it for the conversion of mic ...201425788976
high performance protein-coated microcrystals of rhizomucor miehei lipase: preparation and application for organic synthesis.the goal of obtaining enzyme forms with higher catalytic activity, greater stability, and improved reusability has been pursued for the last few decades. various novel biocatalyst designs have been created, and protein-coated microcrystals (pcmcs) are one of them. pcmc is an enzyme immobilization method based on simultaneous precipitation of protein and carrier, forming micron-sized enzyme-coated crystals. highly active rhizomucor miehei lipase (rml) pcmcs were prepared by immobilizing the prote ...201525800529
incorportation of ethyl esters of epa and dha in soybean lecithin using rhizomucor miehei lipase: effect of additives and solvent-free conditions.the transesterification of soybean lecithin with ethyl esters of polyunsaturated fatty acids (eicosapentaenoic acid (epa) and docosahexaenoic acid (dha)) using immobilized lipase from rhizomucor miehei was tested in the presence or absence of organic solvent (hexane) and additives (urea with ca(2+) or mg(2+)). the reaction was carried out at a water concentration of 4 % and ethyl ester to phospholipid mass ratio of 3:1. after 24 h of reaction without solvent or additive, fatty acid incorporation ...201525894950
lipase-catalyzed acidolysis of tripalmitin with capric acid in organic solvent medium: analysis of the effect of experimental conditions through factorial design and analysis of multiple responses.the acidolysis of tripalmitin with capric acid catalyzed by an immobilized form of a 1,3-positionally selective lipase (rhizomucor miehei) showed to be effective for the synthesis of structured lipids of the mll and mlm type. the effects that reaction parameters such as substrate molar ratio (n), biocatalyst load (e), and reaction temperature (t) have on selected responses variables (i.e. total conversion of tripalmitin, selectivity and yield of the desired structured lipid, hydrolysis yield, an ...201025919616
preparation of highly purified stearidonic acid from echium oil via an enzymatic method combined with preparative high performance liquid chromatography.stearidonic acid (sda), an n-3 polyunsaturated fatty acid (pufa), can be obtained from plant origin oils and it can be a good source of pufa for vegetarians. sda can be easily converted to longer pufa such as docosahexaenoic acid and eicosapentaenoic acid. highly purified stearidonic acid (sda) was prepared successfully from echium oil via an enzymatic method combined with preparative high performance liquid chromatography. in the 1(st) step, sda enrichment was accomplished using candida rugosa ...201525994555
combined use of gap and aox1 promoters and optimization of culture conditions to enhance expression of rhizomucor miehei lipase.rhizo mucor miehei lipase (rml) is an industrially important enzyme, but its application is limited due to its high cost. in this study, a series of measures such as codon optimization, propeptide addition, combined use of gap and aox1 promoters, and optimization of culture conditions were employed to increase the expression of rml. three transformants of the constitutive-inducible combined pichia pastoris strains were generated by transforming the pgapzαa-rml vector into the ppic9k-rml/gs115 st ...201526013734
structural insights into the substrate specificity of two esterases from the thermophilic rhizomucor miehei.two hormone-sensitive lipase (hsl) family esterases (rmesta and rmestb) from the thermophilic fungus rhizomucor miehei, exhibiting distinct substrate specificity, have been recently reported to show great potential in industrial applications. in this study, the crystal structures of rmesta and rmestb were determined at 2.15 å and 2.43 å resolutions, respectively. the structures of rmesta and rmestb showed two distinctive domains, a catalytic domain and a cap domain, with the classical α/β-hydrol ...201526108223
enzymatic kinetic resolution of racemic ibuprofen: past, present and future.this review is a journey concerning the investigations of the kinetic resolution of racemic ibuprofen for the last 20 years. the relevancy of the pharmacological uses of the s( + ) enantiomer along with its higher cost compared with racemic profen are the driving forces of a variety of scientific research studies addressing the enzymatic resolution of ibuprofen through enantiomeric esterification using lipases as biocatalysts. lipases of fungal sources such as candida rugosa, rhizomucor miehei a ...201626121932
biotransformation of oleanolic and maslinic methyl esters by rhizomucor miehei cect 2749.the pentacyclic triterpenoids methyl oleanolate, methyl maslinate, methyl 3β-hydroxyolean-9(11),12-dien-28-oate, and methyl 2α,3β-dihydroxy-12β,13β-epoxyolean-28-oate were biotransformed by rhizomucor miehei cect 2749. microbial transformation of methyl oleanolate produced only a 7β,30-dihydroxylated metabolite with a conjugated 9(11),12-diene system in the c ring. biotransformation of the substrate with this 9(11),12-diene system gave the same 7β,30-dihydroxylated compound together with a 7β,15 ...201526232553
the first crystal structure of a glycoside hydrolase family 17 β-1,3-glucanosyltransferase displays a unique catalytic cleft.β-1,3-glucanosyltransferase (ec 2.4.1.-) plays an important role in the formation of branched glucans, as well as in cell-wall assembly and rearrangement in fungi and yeasts. the crystal structures of a novel glycoside hydrolase (gh) family 17 β-1,3-glucanosyltransferase from rhizomucor miehei (rmbgt17a) and the complexes of its active-site mutant (e189a) with two substrates were solved at resolutions of 1.30, 2.30 and 2.27 å, respectively. the overall structure of rmbgt17a had the characteristi ...201526249352
macrocyclic trichothecenes from myrothecium roridum strain m10 with motility inhibitory and zoosporicidal activities against phytophthora nicotianae.the cytotoxicity of the extract obtained from myrothecium roridum m10 and a characteristic (1)h signal at δh ∼8 led to the assumption that verrucarin/roridin-type compounds were present. upscaling on rice medium led to the isolation of four new metabolites: verrucarins y (1) and z (6) (macrocyclic trichothecenes), bilain d (12) (a diketopiperazine derivative), and hamavellone c (14) (an unusual cyclopropyl diketone). in addition, nine known trichothecenes [verrucarin a (3), 16-hydroxyverrucarin ...201526320597
enhanced production of industrial enzymes in mucoromycotina fungi during solid-state fermentation of agricultural wastes/by-products.cellulolytic, lipolytic and proteolytic enzyme production of zygomycetes mucor corticolus, rhizomucor miehei, gilbertella persicaria and rhizopus niveus were investigated using agro-industrial wastes as substrates. solid-state cultures were carried out on untreated corn residues (stalk and leaf) as single substrate (ssf1) or corn residues and wheat bran in mixed fermentation (ssf2). rapid production of endoglucanase (cmcase) was observed with maximal activity reaching after about 48-h fermentati ...201526344030
structure of product-bound smg1 lipase: active site gating implications.monoacylglycerol and diacylglycerol lipases are industrially interesting enzymes, due to the health benefits that arise from the consumption of diglycerides compared to the traditional triglyceride oils. most lipases possess an α-helix (lid) directly over the catalytic pocket which regulates the activity of the enzyme. generally, lipases exist in active and inactive conformations, depending on the positioning of this lid subdomain. however, lipase smg1, a monoacylglycerol and diacylglycerol spec ...201526365206
crystal structure and characterization of a novel l-serine ammonia-lyase from rhizomucor miehei.l-serine ammonia-lyase, as a member of the β-family of pyridoxal-5'-phosphate (plp) dependent enzymes, catalyzes the conversion of l-serine (l-threonine) to pyruvate (α-ketobutyrate) and ammonia. the crystal structure of l-serine ammonia-lyase from rhizomucor miehei (rmsdh) was solved at 1.76 å resolution by x-ray diffraction method. the overall structure of rmsdh had the characteristic β-family plp dependent enzyme fold. it consisted of two distinct domains, both of which show the typical open ...201526367174
modulating the function of a β-1,3-glucanosyltransferase to that of an endo-β-1,3-glucanase by structure-based protein engineering.a glycoside hydrolase (gh) family 17 β-1,3-glucanosyltransferase (rmbgt17a) from rhizomucor miehei cau432 (cgmcc no. 4967) shared very low sequence homology (∼20 % identity) with that of other β-1,3-glucanases,despite their similar structural folds. structural comparison and sequence alignment between rmbgt17a and gh family 17 β-1,3-glucanases suggested important roles for three residues (tyr102, trp157, and glu158) located in the substrate-binding cleft of rmbgt17a in transglycosylation activit ...201626490553
a unique gcn5-related glucosamine n-acetyltransferase region exist in the fungal multi-domain glycoside hydrolase family 3 β-n-acetylglucosaminidase.glycoside hydrolase (gh) family 3 β-n-acetylglucosaminidases widely exist in the filamentous fungi, which may play a key role in chitin metabolism of fungi. a multi-domain gh family 3 β-n-acetylglucosaminidase from rhizomucor miehei (rmnag), exhibiting a potential n-acetyltransferase region, has been recently reported to show great potential in industrial applications. in this study, the crystal structure of rmnag was determined at 2.80 å resolution. the three-dimensional structure of rmnag show ...201526669854
lipase-catalyzed synthesis of palmitanilide: kinetic model and antimicrobial activity study.enzymatic syntheses of fatty acid anilides are important owing to their wide range of industrial applications in detergents, shampoo, cosmetics, and surfactant formulations. the amidation reaction of mucor miehei lipase lipozyme im20 was investigated for direct amidation of triacylglycerol in organic solvents. the process parameters (reaction temperature, substrate molar ratio, enzyme amount) were optimized to achieve the highest yield of anilide. the maximum yield of palmitanilide (88.9%) was a ...201626672452
characteristics of esterified rice bran oil converted by enzymatic esterification.in the present study, esterified rice bran oil (erbo) was characterized using enzymatic esterification to improve stability, prevent acidification, enhance health-promoting biological activity and generate ω-3 pufa-rich rice bran oil (rbo). esterification reactions using rbo and ethanol were performed at 50°c under 200 bar with 3% lipozyme tl-im (thermomuces lanuginosa immobilized on silica gel) or rm-im (rhizomucor miehei immobilized on ion exchange resin) for 3 hr under supercritical co2. the ...201526688957
esolvent-free, enzyme-catalyzed biodiesel production from mango, neem, and shea oils via response surface methodology.mango, neem and shea kernels produce non-conventional oils whose potentials are not fully exploited. to give an added value to these oils, they were transesterified into biodiesel in a solvent-free system using immobilized enzyme lipozyme from mucor miehei. the doehlert experimental design was used to evaluate the methyl ester (me) yields as influenced by enzyme concentration-ec, temperature-t, added water content-awc, and reaction time-rt. biodiesel yields were quantified by (1)h nmr spectrosco ...201526698315
biochemical characterization of a novel acidic exochitinase from rhizomucor miehei with antifungal activity.a novel chitinase gene (rmchi44) from rhizomucor miehei was cloned and expressed in escherichia coli as an intracellular soluble and active protein. the recombinant chitinase (rmchi44) was purified to homogeneity and biochemically characterized. the molecular mass of rmchi44 was estimated to be 44.6 kda on sds-page. rmchi44 displayed an acidic ph optimum of 4.5 and was stable within ph 4.5-9.0. the optimal temperature of rmchi44 was found to be 50 °c. the km values of rmchi44 for colloidal chiti ...201626709620
purification and characterization of a novel milk-clotting metalloproteinase from paenibacillus spp. bd3526.in this study, a milk-clotting enzyme (mce) isolated from paenibacillus spp. bd3526 was purified and characterized. the mce was purified 8.9-fold with a 10.11% recovery using ammonium sulfate precipitation and anion-exchange chromatography and the specific milk-clotting activity (mca) reached 6791.73 su/mg. the enzyme was characterized as a 35kda metalloproteinase, and the zymogen of which was encoded by a 1671 bp gene named zinc metalloproteinase precursor (zmp) with a predicted molecular weigh ...201626794311
covalent binding of hyper-activated rhizomucor miehei lipase (rml) on hetero-functionalized siliceous supports.physical adsorption onto hydrophobic supports has proven to be an effective way to improve the activity of lipases. covalent binding, on the other hand, enhances the active lifetime of the immobilized biocatalysts. to combine the benefits of adsorption and covalent binding, immobilization of rml on new hetero-functional supports are reported. for this, chemical modification of silica and silica mesoporous nanoparticles was performed by the simultaneous use of two coupling linkers; octyltriethoxy ...201626812114
solvent-free lipase-catalyzed synthesis of diacylgycerols as low-calorie food ingredients.problems derived from obesity and overweight have recently promoted the development of fat substitutes and other low-calorie foods. on the one hand, fats with short- and medium-chain fatty acids are a source of quick energy, easily hydrolyzable and hardly stored as fat. furthermore, 1,3-diacylglycerols are not hydrolyzed to 2-monoacylglycerols in the gastrointestinal tract, reducing the formation of chylomicron and lowers the serum level of triacylglycerols by decreasing its resynthesis in the e ...201626904539
expression in pichia pastoris and characterization of rhizomucor miehei lipases containing a new propeptide region.a large number of propeptide regions from various proteins have been identified which function as intramolecular chaperones and assist the folding of the respective functional domains. the same polypeptide can fold into an altered conformation because of a mutated intramolecular chaperone and can maintain the "memory" of the folding process (new physicochemical properties). two new kinds of rhizomucor miehei lipase (rml) were constructed by replacing its propeptide region with that from either r ...201626923128
naringin lauroyl ester inhibits lipopolysaccharide-induced activation of nuclear factor κb signaling in macrophages.naringin (nar) has antioxidant and anti-inflammatory properties. it was recently reported that enzymatic modification of nar enhanced its functions. here, we acylated nar with fatty acids of different sizes (c2-c18) using immobilized lipase from rhizomucor miehei and investigated the anti-inflammatory effects of these molecules. treatment of murine macrophage raw264.7 cells with nar alkyl esters inhibited lipopolysaccharide (lps)-induced nitric oxide (no) production, with nar lauroyl ester (nar- ...201626967587
intense pegylation of enzyme surfaces: relevant stabilizing effects.this chapter describes the physicochemical coating of the surface of immobilized enzymes with a dense layer of polyethylene glycol (peg) to improve enzyme stability. one hypothesis is that a dense, viscous, polar peg layer around the enzyme would enhance enzyme thermal stability, while still providing access to the active site. peg groups were attached by using aldehyde-dextran polymers, the dextran polymers are in turn attached to the enzyme surface that have been enriched with excess primary a ...201627112394
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