Production Of Ethyl Esters Research Articles

Protic ionic liquid as additive on lipase immobilization using silica sol–gel

Ionic liquids (ILs) have evolved as a new type of non-aqueous solvents for biocatalysis, mainly due to their unique and tunable physical properties. A number of recent review papers have described a variety of enzymatic reactions conducted in IL solutions, on the other hand, to improve the enzyme's activity and stability in ILs; major methods being explored include the enzyme immobilization (on solid support, sol–gel, etc.), protic ionic liquids used as an additive process. The immobilization of the lipase from Burkholderia cepacia by the sol–gel technique using protic ionic liquids (PIL) as additives to protect against inactivation of the lipase due to release of alcohol and shrinkage of the gel during the sol–gel process was investigated in this study. The influence of various factors such as the length of the alkyl chain of protic ionic liquids (monoethanolamine-based) and a concentration range between 0.5 and 3.0% (w/v) were evaluated. The resulting hydrophobic matrices and immobilized lipases were characterised with regard to specific surface area, adsorption–desorption isotherms, pore volume (Vp) and size (dp) according to nitrogen adsorption and scanning electron microscopy (SEM), physico-chemical properties (thermogravimetric – TG, differential scanning calorimetry – DSC and Fourier transform infrared spectroscopy – FTIR) and the potential for ethyl ester and emulsifier production. The total activity yields (Ya) for matrices of immobilized lipase employing protic ionic liquids as additives always resulted in higher values compared with the sample absent the protic ionic liquids, which represents 35-fold increase in recovery of enzymatic activity using the more hydrophobic protic ionic liquids. Compared with arrays of the immobilized biocatalyst without additive, in general, the immobilized biocatalyst in the presence of protic ionic liquids showed increased values of surface area (143–245m2g−1) and pore size (19–38Å). Immobilization with protic ionic liquids also favoured reduced mass loss according to TG curves (always less than 42.9%) when compared to the immobilized matrix without protic ionic liquids (45.1%), except for the sample containing 3.0% protic ionic liquids (46.5%), verified by thermogravimetric analysis. Ionic liquids containing a more hydrophobic alkyl group in the cationic moiety were beneficial for recovery of the activity of the immobilized lipase. The physico-chemical characterization confirmed the presence of the enzyme and its immobilized derivatives obtained in this study by identifying the presence of amino groups, and profiling enthalpy changes of mass loss.

Enzymatic production of ethyl esters from castor oil

iodiesel synthesis through transesterificación of castor oil with ethanol using n-hexane as a solvent and a lipozyme TL IM commercial lipase as a biocatalyst was studied. The effect of ethanol molar relation to oil (3:1-10:1), temperature of reaction (35-65ºC), initial enzymatic charge (5-20% p/p) and amount of water (0-10% p/p) was investigated. The maximum percentage of bio-diesel (ethyl-esters) was obtained at a temperature of 35ºC, a 5:1 ethanol to oil molar ratio, an initial enzymatic charge of 15 % p/p and an initial water concentration of 2% p/p, both of them based on the castor oil weight. A simplified model was proposed to describe the enzymatic kinetics of castor oil transesterification with ethanol, based on the ping-pong Bi Bi mechanism with competitive inhibition for alcohol. The kinetic parameters of the model were estimated graphically and parametrically; a good approach among the results foreseen by the model and experimental data was found at low ethanol concentration (40-80 mol Kg-1).

Yeast ratio is a critical factor for sequential fermentation of papaya wine by Williopsis saturnus and Saccharomyces cerevisiae

SummaryThe growth kinetics and fermentation performance of Williopsis saturnus and Saccharomyces cerevisiae at ratios of 10:1, 1:1 and 1:10 (W.:S.) were studied in papaya juice with initial 7-day fermentation by W. saturnus, followed by S. cerevisiae. The growth kinetics of W. saturnus were similar at all ratios, but its maximum cell count decreased as the proportion of S. cerevisiae was increased. Conversely, there was an early death of S. cerevisiae at the ratio of 10:1. Williopsis saturnus was the dominant yeast at 10:1 ratio that produced papaya wine with elevated concentrations of acetate esters. On the other hand, 1:1 and 1:10 ratios allowed the coexistence of both yeasts which enabled the flavour-enhancing potential of W. saturnus as well as the ethyl ester and alcohol-producing abilities of S. cerevisiae. In particular, 1:1 and 1:10 ratios resulted in production of more ethyl esters, alcohols and 2-phenylethyl acetate. However, the persistence of both yeasts at 1:1 and 1:10 ratios led to formation of high levels of acetic acid. The findings suggest that yeast ratio is a critical factor for sequential fermentation of papaya wine by W. saturnus and S. cerevisiae as a strategy to modulate papaya wine flavour.

QTL mapping of the production of wine aroma compounds by yeast

BackgroundWine aroma results from the combination of numerous volatile compounds, some produced by yeast and others produced in the grapes and further metabolized by yeast. However, little is known about the consequences of the genetic variation of yeast on the production of these volatile metabolites, or on the metabolic pathways involved in the metabolism of grape compounds. As a tool to decipher how wine aroma develops, we analyzed, under two experimental conditions, the production of 44 compounds by a population of 30 segregants from a cross between a laboratory strain and an industrial strain genotyped at high density.ResultsWe detected eight genomic regions explaining the diversity concerning 15 compounds, some produced de novo by yeast, such as nerolidol, ethyl esters and phenyl ethanol, and others derived from grape compounds such as citronellol, and cis-rose oxide. In three of these eight regions, we identified genes involved in the phenotype. Hemizygote comparison allowed the attribution of differences in the production of nerolidol and 2-phenyl ethanol to the PDR8 and ABZ1 genes, respectively. Deletion of a PLB2 gene confirmed its involvement in the production of ethyl esters. A comparison of allelic variants of PDR8 and ABZ1 in a set of available sequences revealed that both genes present a higher than expected number of non-synonymous mutations indicating possible balancing selection.ConclusionsThis study illustrates the value of QTL analysis for the analysis of metabolic traits, and in particular the production of wine aromas. It also identifies the particular role of the PDR8 gene in the production of farnesyldiphosphate derivatives, of ABZ1 in the production of numerous compounds and of PLB2 in ethyl ester synthesis. This work also provides a basis for elucidating the metabolism of various grape compounds, such as citronellol and cis-rose oxide.

Process Optimization for Ethyl Ester Production in Fixed Bed Reactor Using Calcium Oxide Impregnated Palm Shell Activated Carbon (CaO/PSAC)

The continuous production of ethyl ester was studied by using a steady-state fixed bed reactor (FBR). Transesterification of palm stearin (PS) and waste cooking palm oil (WCPO) with ethanol in the presence of calcium oxide impregnated palm shell activated carbon (CaO/PSAC) solid catalyst was investigated. This work was determined the optimum conditions for the production of ethyl ester from PS and WCPO in order to obtain fatty acid ethyl ester (FAEE) with the highest yield. The effects of reaction variables such as residence time, ethanol/oil molar ratio, reaction temperature, catalyst bed height and reusability of catalyst in a reactor system on the yield of biodiesel were considered. The optimum conditions were the residence time 2-3 h, ethanol/oil molar ratio 16-20, reaction temperature at 800C, and catalyst bed height 300 mm which yielded 89.46% and 83.32% of the PS and WCPO conversion, respectively. CaO/PSAC could be used repeatedly for 4 times without any activation treatment and no obvious activity loss was observed. It has potential for industrial application in the transesterification of triglyceride (TG). The fuel properties of biodiesel were determined.

Lipase‐catalysed biodiesel production from Jatropha curcas oil

AbstractBiodiesel as fatty acid alkylesters has become attractive because of its environmental benefits. A non‐edible oil as starting material for biodiesel production appears desirable and does not compromise the edible oils used mainly for food and feed. The present article discusses the enzymatic alcoholysis of crude Jatropha curcas oil in solvent free medium for the production of valuable fatty acid alkyl esters for use as biodiesel. Among various microbial lipases commonly tested in the literature, the highest initial rate (>18 μmol h–1 mg–1) with different alcohols was observed with immobilized lipase from Pseudomonas cepacia, but the activity depends on the amount of water. The best conversion (93%) to produce ethyl esters was achieved with lipase immobilized on the polypropylene carrier Accurel 1282 after 16 h at low enzyme concentration (3% w/w). Moreover, the transesterification could be conducted for at least 160 h during 10 batch runs without significant loss of activity. This reduces the costs for immobilized lipase and can thus make the enzymatic biodiesel production commercially more viable, especially starting from a non‐edible plant oil.

Biodiesel synthesis by a one-step method in a genetically engineered Escherichia coli using rice straw hydrolysate and restaurant oil wastes as raw materials

To reduce the cost of biodiesel, the utilization of rice straw hydrolysate and restaurant oil wastes as the substrates for biodiesel production in a recombinant strain by a one-step method was investigated. A recombinant Escherichia coli pET28a (+)-PAW, which encodes enzymes for the ethanol pathway and acyltransferase, was constructed. Fermentation results in Luria-Bertani medium revealed that xylose was favourable for fatty acid ethyl esters (FAEEs) production (2.79 g l(-1) ) by E. coli pET28a (+)-PAW. When rice straw hydrolysate and restaurant oil wastes were utilized as the monosaccharide substituent and the fatty acids substituent, 0.27 g l(-1) FAEEs and 0.249 g l(-1) FAEEs were obtained, respectively. 1.27 g l(-1) FAEEs was obtained in the restaurant oil wastes medium supplemented by 2% sodium oleate. The fermentation results indicated that the strain was effective in biodiesel production. The rice straw hydrolysate and restaurant oil wastes could be utilized by E. coli as the substrates for FAEE production. This novel exploration might pave the way for biodiesel production from waste materials by genetically engineered microorganism.

Transgenic Corn Oil for Biodiesel Production via Enzymatic Catalysis with Ethanol

This work aims to study the production of fatty acid ethyl esters (FAEE) from a transgenic corn oil, through transesterification using supported enzymes as catalyst (Lipozyme TL IM from Novozymes) and ethanol as reagent. First, the corn oil was characterized for its acid value (0.26 mg KOH/g oil), iodine number (127 g iodine/100 g oil), kinematic viscosity at 40 °C (36.27 mm2/s), density at 20 °C (919 kg/m3) and water content (749 mg/kg). Second, the best operating conditions to perform the transesterification reaction were determined, by testing the following experimental conditions: oil/ alcohol molar ratio (1:3, 1:6 and 1:9), catalyst/ oil mass ratio (2.3, 2.8 and 3.3 wt%), reaction time (8 and 12 h) and reaction temperature (35 and 45 °C). Results showed that although some of the quality parameters analyzed were out of the EN 14214:2009 standard limits (namely the kinematic viscosity, water content, acid value and group I metals) the best operating conditions for a good biodiesel quality (with 69.2 wt% of FAEE content) and the highest reaction yield (98.95 wt%) are an oil/ alcohol molar ratio of 1:6, a catalyst/ oil mass ratio of 2.8 wt%, a reaction time of 12 h and a reaction temperature of 35 °C.

Biodiesel production by two-stage transesterification with ethanol by washing with neutral water and water saturated with carbon dioxide

Industrial production of ethyl esters is impeded by difficulties in purifying the product due to high amounts of soap formed during transesterification. A simple biodiesel wash process was developed that allows successful purification of samples containing high amounts of soap. The key step was a first washing with neutral water, which removed the soaps without increasing the acidity or affecting the process yield. Afterward, the biodiesel was washed with water saturated with CO2, a mild acid that neutralized the remaining soaps and extracted impurities. The acidity, free-glycerine, methanol and soaps concentrations were reduced to very low levels with high efficiency, and using non-corrosive acids. Independently of the initial acidity, it was possible to obtain biodiesel within EN14214 specifications. The process included the recovery of soaps by hydrolysis and esterification, making it possible to obtain the theoretical maximum amount of biodiesel.

Continuous production of fatty acid ethyl esters from soybean oil at supercritical conditions

This work reports the production of fatty acid ethyl esters (FAEE) from the transesterification of soybean oil in supercritical ethanol in a continuous catalyst-free process using different reactor configurations. Experiments were performed in a tubular reactor in one-step reaction and experimentally simulating two reactors, one operated in series and the other a recycle reactor. The reaction products were analyzed for their content of residual triglycerides, glycerol, monoglycerides, diglycerides, ethyl esters and decomposition. Results show that the configurations studied with intermediate separation of glycerol afford higher conversions of vegetable oil to their fatty acid ethyl esters derivatives when compared to the one-step reaction, with relatively low decomposition of fatty acids (< 5.0 wt%).

Continuous production of fatty acid ethyl esters from sunflower oil using supercritical ethanol

The production of first generation biofuels has increased in the last few years because of the rising price of fossil fuels and environmental policies. Biodiesel process alternatives have been proposed in order to achieve higher yields, non-catalytic and more environmentally friendly processes, a greater profit from by-products and particularly the possibility of using low quality and cheaper feedstocks. In this regard, one of the most studied technologies has been the non-catalytic supercritical transesterification of fats and raw vegetable oils.This work reports results on the continuous production of fatty acid ethyl esters (FAEEs) from the non-catalytic supercritical ethanolysis of sunflower oil. The reaction was carried out in the following range of operating conditions: (i) ethanol-to-oil molar ratio of 40:1; (ii) temperature and pressure range, 573–618K and 165–200bar and (iii) mass flow rates varying from 3 to 16g/min. Given the high sensitivity of the specific density in supercritical mixtures, the mixture residence time in the reactor was estimated based on experimental data of the reactive mixture density. Moreover, we show here that overlooking the use of this experimental data and assuming ideal solution behavior for density calculation, which is usually done, may lead to important deviations in the kinetic model parameters. The mixture densities were correlated with the Peng–Robinson equation of state (PR-EoS). In the range of operating conditions studied in this work, up to 90% by mass fraction of fatty ester was obtained.

Use of baru oil (Dipteryx alata Vog.) to produce biodiesel and study of the physical and chemical characteristics of biodiesel/petroleum diesel fuel blends

We describe production of methyl and ethyl esters derived from baru oil (Dipteryx alata Vog.). Water and alcohols are removed from the biodiesel obtained by simple distillation. We study the acidity, density, iodine number, viscosity, water content, peroxide number, external appearance, and saponification number of the oil, its methyl and ethyl esters (biodiesels) and their blends (B5, B10, B15, B20, and B30) with commercial diesel fuel.

Functional expression and characterization of five wax ester synthases in Saccharomyces cerevisiae and their utility for biodiesel production

BackgroundWax ester synthases (WSs) can synthesize wax esters from alcohols and fatty acyl coenzyme A thioesters. The knowledge of the preferred substrates for each WS allows the use of yeast cells for the production of wax esters that are high-value materials and can be used in a variety of industrial applications. The products of WSs include fatty acid ethyl esters, which can be directly used as biodiesel.ResultsHere, heterologous WSs derived from five different organisms were successfully expressed and evaluated for their substrate preference in Saccharomyces cerevisiae. We investigated the potential of the different WSs for biodiesel (that is, fatty acid ethyl esters) production in S. cerevisiae. All investigated WSs, from Acinetobacter baylyi ADP1, Marinobacter hydrocarbonoclasticus DSM 8798, Rhodococcus opacus PD630, Mus musculus C57BL/6 and Psychrobacter arcticus 273-4, have different substrate specificities, but they can all lead to the formation of biodiesel. The best biodiesel producing strain was found to be the one expressing WS from M. hydrocarbonoclasticus DSM 8798 that resulted in a biodiesel titer of 6.3 mg/L. To further enhance biodiesel production, acetyl coenzyme A carboxylase was up-regulated, which resulted in a 30% increase in biodiesel production.ConclusionsFive WSs from different species were functionally expressed and their substrate preference characterized in S. cerevisiae, thus constructing cell factories for the production of specific kinds of wax ester. WS from M. hydrocarbonoclasticus showed the highest preference for ethanol compared to the other WSs, and could permit the engineered S. cerevisiae to produce biodiesel.

Synthetic resin-bound truncated Candida antarctica lipase B for production of fatty acid alkyl esters by transesterification of corn and soybean oils with ethanol or butanol

A gene encoding a synthetic truncated Candida antarctica lipase B (CALB) was generated via automated PCR and expressed in Saccharomyces cerevisiae. Western blot analysis detected five truncated CALB variants, suggesting multiple translation starts from the six in-frame ATG codons. The longest open reading frame, which corresponds to amino acids 35-317 of the mature lipase, appeared to be expressed in the greatest amount. The truncated CALB was immobilized on Sepabeads® EC-EP resin and used to produce ethyl and butyl esters from crude corn oil and refined soybean oil. The yield of ethyl esters was 4-fold greater from corn oil than from soybean oil and was 36% and 50% higher, respectively, when compared to a commercially available lipase resin (Novozym 435) using the same substrates. A 5:1 (v/v) ratio of ethanol to corn oil produced 3.7-fold and 8.4-fold greater yields than ratios of 15:1 and 30:1, respectively. With corn oil, butyl ester production was 56% higher than ethyl ester production. Addition of an ionic catalytic resin step prior to the CALB resin increased yields of ethyl esters from corn oil by 53% compared to CALB resin followed by ionic resin. The results suggest resin-bound truncated CALB has potential application in biodiesel production using biocatalysts.

Characterization of Smallest Active Monomeric Lipase from Novel Rhizopus Strain: Application in Transesterification

An extracellular lipase-producing fungus was isolated from oil-rich soil. This fungus belongs to the genus Rhizopus and clades with Rhizopus oryzae. Lipase was purified to homogeneity from this novel fungal source using ammonium sulphate precipitation followed by Q-Sepharose chromatography. The extracellular lipase was purified 8.6-fold, and enzymatic properties were studied. The molecular mass of the purified enzyme was estimated to be 17 kD by sodium dodecyl sulphate-polyacrylamide gel electrophoresis and 16.25 kD by matrix-assisted laser desorption ionization/time-of-flight analysis. The native molecular mass was estimated to be 17.5 kD by gel filtration, indicating the protein to be monomer. The optimum pH and temperature for the enzyme catalysis were 7.0°C and 40°C, respectively. Enzyme was stable in pH range 6.0-7.0 and retains 95-100% activity when incubated at 50°C for 1h. The pI of the purified lipase was 4.2. Enzyme was stable in the organic solvents such as ethanol, hexane and methanol for 2h. Purified enzyme was used for transesterification of oleic acid in the presence of ethanol for production of oleic acid ethyl ester with a conversion efficiency of 66% after 24h at 30°C.

Ethanol treatment inhibits internal ethylene concentrations and enhances ethyl ester production during storage of oriental sweet melons (Cucumis melo var. makuwa Makino)

Compared to other melon types, oriental sweet melon (Cucumis melo var. makuwa Makino) is quite a different species with a poor shelf-life due to its typical climacteric behaviour, and thin pericarp and rind. In order to investigate the effect of ethanol application on postharvest storage at room temperature (24°C) and quality of oriental sweet melon, we measured physiological and quality changes induced by ethanol vapor or ethanol injection. Both ethanol treatments significantly inhibited internal ethylene concentrations (IEC), and no ethylene peak occurred when compared with control fruit during storage. However, both ethanol treatments maintained firmness but without significant differences between ethanol-treated and the control melons, except with ethanol injection on day 4. Soluble solids contents were not affected by either treatments. Glucose, fructose and sucrose contents showed a greater increase in ethanol-treated melon flesh and peel tissues than in controls after four days, especially sucrose, the main sugar in melons. Compared with the control, both ethanol treatments resulted in different profiles and composition of aromatic volatile compounds during storage. Both ethanol treatments resulted in a significant increase in ethyl acetate, hexyl acetate and 2-methyl-1-butyle acetate, and a decrease of 2,3-butanediyl diacetate, phenylmethyl acetate and 2-phenethyl acetate. The contents of total esters, including eight newly detected ethyl esters, were 2–4 fold higher in ethanol-treated melons. Ethanol injection more effectively increased accumulation of aroma volatile compounds for a short time, while the effects of ethanol vapor persisted during the storage. Both ethanol treatments increased alcohol acyltransferase (AAT) activity in melon flesh within four days, and levels peaked three days earlier but lower than in the control. There were no significant differences in activities of alcohol dehydrogenase (ADH) and lipoxygenase (LOX) in ethanol-treated and control melons. In summary, postharvest ethanol application reduced the IEC of harvested oriental melons and improved levels of volatile aroma compounds, especially the ethyl esters.

Functional expression and characterization of five wax ester synthases in Saccharomyces cerevisiae and their utility for biodiesel production

Wax ester synthases (WSs) can synthesize wax esters from alcohols and fatty acyl coenzyme A thioesters. The knowledge of the preferred substrates for each WS allows the use of yeast cells for the production of wax esters that are high-value materials and can be used in a variety of industrial applications. The products of WSs include fatty acid ethyl esters, which can be directly used as biodiesel. Here, heterologous WSs derived from five different organisms were successfully expressed and evaluated for their substrate preference in Saccharomyces cerevisiae. We investigated the potential of the different WSs for biodiesel (that is, fatty acid ethyl esters) production in S. cerevisiae. All investigated WSs, from Acinetobacter baylyi ADP1, Marinobacter hydrocarbonoclasticus DSM 8798, Rhodococcus opacus PD630, Mus musculus C57BL/6 and Psychrobacter arcticus 273-4, have different substrate specificities, but they can all lead to the formation of biodiesel. The best biodiesel producing strain was found to be the one expressing WS from M. hydrocarbonoclasticus DSM 8798 that resulted in a biodiesel titer of 6.3 mg/L. To further enhance biodiesel production, acetyl coenzyme A carboxylase was up-regulated, which resulted in a 30% increase in biodiesel production. Five WSs from different species were functionally expressed and their substrate preference characterized in S. cerevisiae, thus constructing cell factories for the production of specific kinds of wax ester. WS from M. hydrocarbonoclasticus showed the highest preference for ethanol compared to the other WSs, and could permit the engineered S. cerevisiae to produce biodiesel.

ジェネリック医薬品の品質評価（1）―イコサペント酸エチル製剤における官能試験および成分分析試験―

The overall quality of generic drugs (GE) was assessed by sensory evaluation (questionnaire survey) taken by the patient side, a composition analysis by the pharmacist side, and a questionnaire by medical manufacturers, using an icosapentaenoic acid ethyl ester (EPA-E) product. In the sensory evaluation, the original product was superior to the two other GEs in terms of the ease of finding the wrapping's cutting point and its opening and external cutting points. In addition, there were GE products with a peculiar odor, which had residual beads (grain) in several wrappings. According to an analysis of the capsule's odors and surface cleaning solutions, the odor was attributed to the raw material itself adhering to the capsule surfaces during the manufacturing process, and/or by the deterioration of the capsules during the manufacturing period. The result of the stress test also supported this conclusion. The total dioxin content in the original product was extremely low compared to any other GE product. Questionnaires to manufacturers showed that all supplied product information for medical personnel and patients via various media, and were striving to innovate and improve the quality retention of the wrapping. It also emerged that GEs were not always superior to the original product, whereas it is expected that GE manufacturers will provide products that improve on the original drugs for the convenience of patients.

Possibility of Automation of a Mobile Biodiesel Production Plant

This paper presents a method of production and properties of ethyl esters as well as the differences between them and methyl esters. It discusses the technology of esterification and the benefits brought by the use of rapeseed ethyl esters as renewable fuel. It also presents elements of structure, actuators and control mechanisms of a mobile biodiesel production plant, owned by the Department of Mechatronics, University of Warmia and Mazury. An algorithm of a transesterification process is presented along with algorithms of a flow-through process control and the possibilities of their automation. The benefits of applying such a solution are also discussed.

Biodiesel production by two-stage transesterification with ethanol

A two-stage process consisting of two reactions steps with glycerin separation and ethanol/catalyst addition in each of them was optimized for ethyl esters production. The optimal reaction temperature was 55°C. At an ethanol/oil molar ratio of 4.25:1 (25%v/v alcohol with respect to oil), a 99% conversion value was obtained with low ethanol consumption. In contrast to methoxide catalysts, sodium and potassium hydroxide catalysts severely complicate the purification since no phase separation took place under most conditions. With a total sodium methoxide concentration of 1.06g catalyst/100g oil, and adding 50% of the catalyst in each reaction step, biodiesel with a total glycerin content of 0.172% was obtained. The optimal conditions found in this study make it possible to use the same industrial facility to produce either methyl or ethyl esters.