DigitalUM :: Browsing by Subject "Biocatalysis"

Browsing by Subject "Biocatalysis"

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Open Access
A green chemo-enzymatic approach for CO2 capture and transformation into bis(cyclic carbonate) esters in solvent-free media
(American Chemical Society, 2024-10-02) Ruiz, Francisco J.; Velasco, Francisco; Porcar, Raul; Garcia Verdugo, Eduardo; Villa Aroca, Rocío; Lozano Rodríguez, Pedro; Nieto Cerón, Susana; Bioquímica y Biología Molecular B e Inmunología
A sustainable approach for CO2 capture and chemo-enzymatic transformation into bis(cyclic carbonate) esters from CO2, glycidol and organic anhydrides under solvent-free conditions has been demonstrated. The chemo-enzymatic process is based in two consecutive catalytic steps, which can be executed through separated operations, or within a one-pot combo system, taking advantage of the synergic effects that emerge from integrating ionic liquid (ILs) technologies and biocatalysts. In a first step, lipase-catalyzed transesterification and esterification reactions of different diacyl donors (e.g. glutaric anhydride, succinic anhydride, dimethyl succinate, etc.) with glycidol in solvent-free under mild reaction conditions (70 °C, 6 h), producing the corresponding diglycidyl esters derivatives up to 41% yield. By a second step, the synthesis of bis(cyclic carbonate) esters was carried out as results of the cycloaddition reaction of CO2 (from an exhausted gas source, 15% CO2 purity) on these diglycidyl esters, catalyzed by the covalently attached 1-decyl-2-methylimidazolium IL (Supported Ionic Liquid-Like Phase, SILLP), in solvent-free, leading up to 65% yield after 8 h at 50 °C and 1MPa CO2 pressure. Both key elements of the reaction system (biocatalyst and SILLP) were successfully recovered and reused for at least 5 operational cycles. Finally, different metrics have been applied to assess the greenness of the solvent-free chemo-enzymatic synthesis of bis(cyclic carbonate) esters here reported.
Open Access
A simplified kinetic model to describe the solvent-free enzymatic synthesis of wax esters
(2021-04-17) Serrano-Arnaldos, M.; Murcia, M.D.; Ortega Requena, Salvadora; Montiel, M.C.; Máximo, F.; Gómez, E.; Bastida, J.; Ingeniería Química
BACKGROUND: The use of biotechnological processes at industrial scale is a promising tool to replace conventional synthesis as an efficient and eco-friendly technology. For that purpose, the kinetic modelling of an in-lab optimized enzymatic process prior to scaling-up is of great utility. RESULTS: In this work, a kinetic model for the solvent-free synthesis of cetyl laurate, myristate, palmitate and stearate using different commercial immobilized lipases has been developed. In order to describe the esterification process of the cetyl esters separately and as a mixture similar to natural spermaceti, a pseudo-first-order kinetic has been proposed and tested. A relation between the inverse values of the kinetic constant and the amount of biocatalyst has been observed. The effect of temperature on the reaction rate can be accurately described by the Arrhenius equation except for immobilized Thermomyces lanuginosus, which appears to be less resistant to temperatures above 70 °C. CONCLUSION: Low deviations between experimental and predicted values (R2 ≥ 0.99) indicate that this pseudo-first-order kinetic model can be considered valid for the data range studied. In addition, the reaction rate of spermaceti can be successfully predicted through a weighted average of the kinetic constants obtained during the synthesis of each cetyl ester. This simple but accurate kinetic model for describing the solvent-free enzymatic biosynthesis of wax esters from spermaceti may contribute to extending the application of lipases as industrial catalysts.
Open Access
(Bio) Catalytic Continuous Flow Processes in scCO2 and/or ILs: Towards Sustainable: (Bio)Catalytic Synthetic Platforms
(2011) García Verdugo, Eduardo; Santiago Vicente, Luis; Pucheault, Mathieu; Vaultier, Michel; Lozano Rodríguez, Pedro; Bioquímica y Biología Molecular B e Inmunología
Open Access
Biocatalytic intensified process for the synthesis of neopentyl glycol dicaprylate/dicaprate
(Elsevier, 2022-11-07) Máximo, F.; Asensi, M.; Serrano-Arnaldos, M.; Ortega Requena, Salvadora; Montiel, M.; Bastida, J.; Ingeniería Química
Emollient esters are widely used ingredients in the cosmetics industry. Their chemical synthesis requires the use of high temperatures and polluting acid catalysts, resulting in environmentally unfriendly processes. This paper describes, for the first time, the biocatalytic synthesis process of the cosmetic ingredient neopentyl glycol dicaprylate/dicaprate (INCI name), a mixture of branched diesters with excellent emollient properties. The co-esterification of the acids with the alcohol is carried out in a solvent-free system, using the biocatalyst Lipozyme®435, a commercial immobilized derivative of Candida antarctica lipase B marketed by Novozymes. Process intensification has been approached by acting on three different aspects. Firstly, the use of solvent-free systems provides higher yields by operating with smaller reactor volumes. Secondly, the inhibition of the enzymatic activity caused by caprylic and capric acids has determined the need to implement a new reaction strategy consisting in the use of a fed-batch reactor, in which the acid is added to the reactor using a peristaltic pump in order to maintain an optimal acid concentration that minimizes the inhibition effects. Finally, the reusability of the biocatalyst used has been verified, allowing it to be used in at least five consecutive reaction cycles without noticeable loss of activity. All this results in an efficient synthesis process with a process productivity of 0.15 kg product/L reactor·h and a biocatalyst productivity of 167.09 kg product/kg biocatalyst. Only 6 h are needed, operating in a fed-batch reactor at 80 °C, to obtain a product with 92.5% purity. In addition, the most commonly used sustainability indicators have been calculated, reflecting that the biocatalytic process developed for the synthesis of neopentyl glycol dicaprylate/dicaprate complies with many of the principles of “green chemistry” and is suitable for future implementation on an industrial scale.
Open Access
Biocatalytic synthesis of polymeric esters used as emulsifiers
(Croatian Society of Chemical Engineers, 2019) Ortega Requena, Salvadora; Serrano-Arnaldos, M.; Montiel Morte, María Claudia; Máximo, María Fuensanta; Bastida Rodríguez, Josefa; Murcia Almagro, María Dolores; Ingeniería Química
Polyglycerol polyricinoleate (PGPR) is a polymeric ester widely used as emulsifier in the food industry. In this work, PGPR biocatalytic synthesis was carried out in a onestep solvent-free enzymatic process using lipase CALB immobilized in Lewatit® Monoplus MP 64 by adsorption. The optimal immobilization conditions were determined: initial enzyme concentration of 13 mg of Lowry protein per mL phosphate buffer pH 7, and ricinoleic acid as a support activator. An immobilized derivative with 35.93 ± 4.90 mg of Lowry protein per g of dry support was obtained. It was used as a catalyst for PGPR production in open air and vacuum batch reactors, and the results obtained showed that only when the reaction equilibrium was shifted towards ester production by means of water removal, the PGPR produced fulfilled the European legislation (acid value ≤ 6 mg of KOH per g of product).
Open Access
Branched saturated esters and diesters : sustainable synthesis of excellent biolubricants
(Elsevier, 2024-01-08) Máximo, M.; Bastida, J.; Montiel, C.; Gómez, M.; Murcia, M.D.; Barqueros, C.; Ortega Requena, Salvadora; Ingeniería Química
The enzymatic production of biolubricants with desirable properties such as high viscosity index and resistance to oxidation is investigated. These characteristics are ascribed to their branched structure and high molecular weight, as well as, to the absence of unsaturated bonds in the molecule. Solvent-free processes with moderate enzyme concentrations (up to 5% wt.) and reaching conversions of 95% or more, have been conducted. Firstly, up to fifteen branched esters and diesters, all of them saturated, are obtained from a branched acid, 2-methylhexanoic acid, and a variety of linear and branched alcohols and linear diols. Among them, three esters have viscosity indexes close to 200 or higher (1,10-decanediolyl 2-methylhexanoate, 1,12-dodecanediolyl 2-methylhexanoate and 2-octyl-1-dodecanoyl 2-methylhexanoate). For the synthesis of these compounds, optimization of biocatalyst concentration and temperature has been carried out, reaching conversions above 95% within operation times between 2 and 3.5 h.
Embargo
Characterization of the stability of Vibrio fluvialis JS17 amine transaminase
(ELSEVIER, 2018) Chen, Shan; Campillo-Brocal, Jonatan C.; Berglund, Per; Humble, Maria Svedendahl; Genética y Microbiología
The amine transaminase from Vibrio fluvialis (Vf-ATA) is an attractive enzyme with applications within Biocatalysis for the preparation of chiral amines. Various catalytic properties of Vf-ATA have been investigated, but a biophysical characterization of its stability has been lacking. Today, the industrial application of Vf-ATA is limited by its low operational stability. In order to enhance the knowledge regarding the structural stability of ATAs, general characterizations of different ATAs are required. In this work, the stability of Vf-ATA was explored. First, the affinity between enzyme and pyridoxal-5'-phosphate (PLP) (KD value of 7.9 μM) was determined. Addition of PLP to enzyme preparations significantly improved the enzyme thermal stability by preventing enzyme unfolding. With the aim to understand if this was due to the PLP phosphate group coordination into the phosphate group binding cup, the effect of phosphate buffer on the enzyme stability was compared to HEPES buffer. Low concentrations of phosphate buffer showed a positive effect on the enzyme initial activity, while higher phosphate buffer concentrations prevented cofactor dissociation. Additionally, the effects of various amine or ketone substrates on the enzyme stability were explored. All tested amines caused a concentration dependent enzyme inactivation, while the corresponding ketones showed no or stabilizing effects. The enzyme inactivation due to the presence of amine can be connected to the formation of PMP, which forms in the presence of amines in the absence of ketone. Since PMP is not covalently bound to the enzyme, it could readily leave the enzyme upon formation. Exploring the different stability effects of cofactor, substrates, additives and buffer system on ATAs seems to be important in order to understand and improve the general performance of ATAs.
Open Access
Chemo-enzymatic production of omega-3 monoacylglycerides using sponge-like ionic liquids and supercritical carbon dioxide
(2020-07-22) Alvarez, Elena; Donaire González, Antonio; Garcia-Verdugo, Eduardo; Luis, Santiago V; Lozano Rodríguez, Pedro; Nieto Cerón, Susana; Villa Aroca, Rocío; Bioquímica y Biología Molecular B e Inmunología
A clean chemo-enzymatic synthesis of omega-3 monoacylglycerides was carried out by two consecutive catalytic steps, the enzymatic transesterification of raw fish or linseed oil with solketal for producing fatty acid solketyl esters, followed by the hydrolysis of these solketal moieties catalysed by solid acids (e.g. zeolites) in either supercritical carbon dioxide (scCO2) or sponge-like ionic liquids (SLILs). By using scCO2 as reaction/extraction medium, an excellent performance of both coupled catalytic steps was observed when t-butanol was used as a co-solvent, resulting in a 100% monoacylglyceride yield for seven days under continuous operation and without any loss in catalytic activity. For discontunuous operation, the process involved two separated steps in SLIL and water, respectively, leading to 100% product yield and IL-free monoacylglyceride product by following a cooling and centrifugation protocol, which allow for the full recovery of the enzyme / SLIL / zeolite components of the reaction system that could be reused for at least 6 cycles with unchanged catalytic performance.
Restricted
Clean enzymatic production of flavor esters in Spongelike Ionic Liquids
(American Chemical Society, 2019-07-02) Alvarez, Elena; Rodríguez, José; Villa Aroca, Rocío; Gómez, Celia; Donaire, Antonio; Villa Aroca, Rocío; Lozano Rodríguez, Pedro; Nieto Cerón, Susana; Bioquímica y Biología Molecular B e Inmunología
The biocatalytic synthesis of 16 flavor esters was carried out by the direct esterification of aliphatic acids (e.g., acetic, propionic, etc.) with an alcohol (e.g., cinnamyl alcohol, benzyl alcohol, anisyl alcohol, rac-1-phenylethanol, or rac-sulcatol) using hydrophobic ionic liquids (ILs) based on ammonium or imidazolium cations containing a long alkyl side chain (e.g., hexadecyltrimethylammonium bistriflimide, [C16tma][NTf2]) as the reaction medium. As temperature-switchable liquid/solid phases, these ILs behave as spongelike systems (so-called spongelike ionic liquids (SLILs)), which act as excellent monophasic reaction media for the lipase-catalyzed synthesis of flavor esters. Under appropriate selected reaction conditions (e.g., enzyme, substrate molar ratio, nature of the SLIL, etc.), product yields near 100% were obtained for all of the synthesized flavor esters. Because of the unique spongelike properties of these ILs, a separation protocol based on the centrifugation of the solid IL/flavor ester through nylon membranes was successfully used. By means of this approach, the clean separation of all flavor products from the solid reaction media was easily achieved, while the recovered SLIL/biocatalyst system was reused for six consecutive operation cycles with unchanged catalytic performance.
Open Access
Esterification of polyglycerol with polycondensed ricinoleic acid catalysed by immobilized Rhizopus oryzae lipase
(Springer, 2012-12-23) Ortega Requena, Salvadora; Máximo Martín, María Fuensanta; Montiel Morte, María Claudia; Murcia Almagro, María Dolores; Arnold, G.; Bastida Rodríguez, Josefa; Ingeniería Química
The enzymatic method for synthesising polyglycerol polyricinoleate (PGPR), a food additive named E-476, was successfully carried out in the presence of immobilized Rhizopus oryzae lipase in a solvent-free medium. The great advantage of using the commercial preparation of Rhizopus oryzae lipase is that it is 10 times cheaper than the commercial preparation of Rhizopus arrhizus lipase, the biocatalyst used in previous studies. The reaction, which is really a reversal of hydrolysis, takes place in the presence of a very limited amount of aqueous phase. Immobilization of the lipase by physical adsorption onto an anion exchange resin provided good results in terms of activity, enzyme stability and reuse of the immobilized derivative. It has been established that the adsorption of Rhizopus oryzae lipase on Lewatit MonoPlus MP 64 follows a pseudo-second order kinetics, which means that immobilization is a process of chemisorption, while the equilibrium adsorption follows a Langmuir isotherm. The use of this immobilized derivative as catalyst for obtaining PGPR under a controlled atmosphere in a vacuum reactor, with a dry nitrogen flow intake, allowed the synthesis of a product with an acid value lower than 6 mg KOH/g, which complies with the value established by the European Commission Directive. This product also fulfils the European specifications regarding the hydroxyl value and refractive index given for this food additive, one of whose benefits, as proved in our experiments, is that it causes a drastic decrease in the viscosity (by 50%) and yield stress (by 82%) of chocolate, comparable to the impact of customary synthesised PGPR.
Open Access
Esters in the Food and Cosmetic Industries: An Overview of the Reactors Used in Their Biocatalytic Synthesis
(2024-01-04) Ortega Requena, Salvadora; Montiel, C.; Máximo, F.; Gómez, M.; Murcia, M.D.; Bastida, J.; Ingeniería Química
Esters are versatile compounds with a wide range of applications in various industries due to their unique properties and pleasant aromas. Conventionally, the manufacture of these compounds has relied on the chemical route. Nevertheless, this technique employs high temperatures and inorganic catalysts, resulting in undesired additional steps to purify the final product by removing solvent residues, which decreases environmental sustainability and energy efficiency. In accordance with the principles of “Green Chemistry” and the search for more environmentally friendly methods, a new alternative, the enzymatic route, has been introduced. This technique uses low temperatures and does not require the use of solvents, resulting in more environmentally friendly final products. Despite the large number of studies published on the biocatalytic synthesis of esters, little attention has been paid to the reactors used for it. Therefore, it is convenient to gather the scattered information regarding the type of reactor employed in these synthesis reactions, considering the industrial field in which the process is carried out. A comparison between the performance of the different reactor configurations will allow us to draw the appropriate conclusions regarding their suitability for each specific industrial application. This review addresses, for the first time, the above aspects, which will undoubtedly help with the correct industrial implementation of these processes.
Open Access
Guerbet alcohols, ideal substrates for the sustainable production of branched esters
(MDPI, 2025-11-11) Montiel Morte, María Claudia; Máximo, María Fuensanta; Gómez Gómez, María; Murcia Almagro, María Dolores; Ortega Requena, Salvadora; Bastida Rodríguez, Josefa; Ingeniería Química; Facultad de Química
Saturated and branched high molecular weight organic esters are highly valued as emollients in the cosmetic industry due to their superior properties. Their saturated character provides resistance to oxidation and rancidity. Additionally, their branched structure endows them with low melting temperatures, enabling them to remain liquid over a broad temperature range. These esters can be obtained from branched alcohols, branched fatty acids or both, using chemical or enzymatic processes. Among branched alcohols, Guerbet alcohols stand out. Due to their characteristic properties as branched, saturated alcohols with superior oxidative stability and extremely low volatility, they are proposed as excellent substrates for the enzymatic synthesis of these compounds. This study represents the first investigation into the biocatalytic synthesis of three specific esters: those formed between 2-octyl-1-dodecanol (C20 Guerbet alcohol) and the fatty acids myristic (MA), palmitic (PA), and stearic acid (SA). To achieve this, an environmentally sustainable biocatalytic process was developed. The synthesis involves a solvent-free esterification catalyzed by the commercial immobilized lipase, Lipozyme® 435, conducted within a vertically stirred, thermostated batch tank reactor. Optimal conditions for lipase concentration and temperature were established, and the sustainability of the process was successfully quantified using various “green metrics”.
Open Access
Ionic liquids as an enabling tool to integrate reaction and separation processes
(RSC, 2019-10-22) Alvarez, Elena; Porcar, Raul; Garcia-Verdugo, Eduardo; V Luis, Santiago; Lozano Rodríguez, Pedro; Villa Aroca, Rocío; Bioquímica y Biología Molecular B e Inmunología
The development of advanced processes able to directly provide pure products by integrating chemical transformations, product separation and recovery and reuse of the solvent and the catalytic phases by straightforward and smart approaches, is a key feature to build green chemical processes. The unique properties of ILs, one of the key enabling technologies, can lead, when combined with (bio)catalysts, to amazing synergies not only improving the catalytic efficiency (i.e. improved activity and enantioselectivity, enhanced stability, etc.), but also allowing the design of smarts approaches for product separation (e.g. IL/scCO2 biphasic reactors, membrane reactors, nanodrop systems, microfluidic devices, supported ionic liquid phases, sponge-like ionic liquids, etc.), incorporating the full recovery and reuse of the catalyst and the ILs phase. This tutorial review highlights representative examples of ILs-based systems integrating reaction/separation as a tool for the development of sustainable chemical processes leading to clean and pure chemical products.
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Optimized enzymatic synthesis of the food additive polyglycerol polyricinoleate (PGPR) using Novozym® 435 in a solvent free system
(Elsevier, 2014-01-21) Ortega Requena, Salvadora; Bódalo-Santoyo, A.; Bastida Rodríguez, Josefa; Máximo, María Fuensanta; Montiel Morte, María Claudia; Gómez Gómez, María; Ingeniería Química; Facultad de Química
Polyglycerol polyricinoleate (PGPR) is used as an emulsifier in the food industry, especially in chocolate coatings and chocolate bars. PGPR improves the characteristics of molten chocolate by reducing yield stress, facilitating the coating of confectionery pieces, while limiting the amount of cocoa butter involved. The enzymatic synthesis of PGPR catalyzed by lipases presents several advantages over chemical synthesis, including enzyme specificity and the mild conditions needed, thereby avoiding undesirable side-reactions and by-products. A novel process to synthesize PGPR using a biocatalyst, Novozym® 435, is presented. Novozym® 435 is appropriate for catalyzing both the reactions involved in this process. A PGPR fulfilling European specifications for this food additive as well as recommendations set out in the Food Chemical Codex, was obtained using a discontinuous vacuum reactor with a dry nitrogen flow. In addition, the biocatalyst reuse would decrease costs. Moreover, it was confirmed that the ability to obtain PGPR in a one-step reaction significantly shortens the time required.
Open Access
Sustainable set-ups for the biocatalytic production and scale-up of panthenyl monoacyl esters under solvent-free conditions
(American Chemical Society, 2023-03-22) Nieto Cerón, Susana; Bernal Palazón, Juana María; García Verdugo, Eduardo; Donaire González, Antonio; Lozano Rodríguez, Pedro; Villa Aroca, Rocío; Química Inorgánica; Facultades de la UMU::Facultad de Química
A sustainable scaling-up process for the biocatalytic production of new bioactive provitamin-B5 monoacyl esters has been demonstrated. A solvent-free reaction protocol based on the formation of eutectic mixtures between neat substrates render to highly efficient direct esterification of free fatty acids (i.e. from C6 to C18 alkyl chain length) with panthenol catalyzed by lipase. The scale-up from 0.5 to 500 g was evaluated by means of several reaction systems (i.e. ultrasound-assistance, orbital shaking, rotary evaporator, and mechanical stirring coupled to vacuum). For all reactor systems, the yield in panthenyl monoacyl esters was improved by increasing the length of the alkyl chain of the fatty acid (i.e. from 63 % yield for panthenyl butyrate to 83 % yield for panthenyl myristate). The best results (87 % - 95 % product yield, for all cases) were obtained upon a scale-up (50-500 g size) and when a vacuum system was coupled to the biocatalytic reaction unit. Under the optimized conditions a five-fold reduction of the amount of biocatalyst with respect reactors without vacuum was achieved. The recovery and reuse of the immobilized enzyme for 5 operation cycles was also demonstrated. Finally, different metrics have been applied to assess the greenness of the solvent-free biocatalytic synthesis of panthenyl monoesters here reported.
Open Access
Ultrasound-assisted enzymatic synthesis of xylitol fatty acid esters in solvent-free conditions
(Elsevier, 2021-07) Donaire, Antonio; Villa Aroca, Rocío; Lozano Rodríguez, Pedro; Nieto Cerón, Susana; Bioquímica y Biología Molecular B e Inmunología
A commercial immobilized lipase was successfully used for the synthesis of five xylityl acyl esters by means of the esterification of free fatty acids (caprylic, capric, lauric and myristic, respectively) with xylitol under solvent-free conditions. Ultrasound-assistance was shown to be a key tool to overcome the handicap imposed by both the mutual immiscibility of fatty acids and xylitol substrates, and the semisolid character of the initial reaction mixtures. In such semisolid systems, ultrasonic irradiation may enable the transport of substrate molecules to the enzyme catalytic-site, leading to the efficient synthesis of xylityl fatty ester (e.g. up to 95% yield after 90 min at 40ºC), with xylityl monoacyl ester and xylitol diacyl ester appearing as the main products (>96%), assessed by HPLC and NMR analyses. The separation of products was carried out by heating and simple centrifugation of the reaction medium, which was possible due to different densities of the resulting fractions.
Open Access
Understanding the enzymatic synthesis of a new biolubricant: decane-1,10-diyl bis(2-methylpentanoate)
(MDPI, 2024-12-26) Ortega Requena, Salvadora; Máximo, María Fuensanta; Montiel Morte, María Claudia; Gómez Gómez, María; Murcia Almagro, María Dolores; Bastida Rodríguez, Josefa; Ingeniería Química; Facultades de la UMU::Facultad de Química
The value of branched esters comes from the special properties they have in cold environments, which allow them to remain liquid over a wide range of temperatures. These properties make them useful for application in the cosmetic industry or as lubricant additives. This paper presents the studies carried out to ascertain the operational feasibility of the enzymatic esterification of 2-methylpentanoic acid (MPA) with 1,10-decanediol (DD), with the objective of obtaining a novel molecule: decane-1,10-diyl bis(2-methylpentanoate) (DDBMP). The enzymatic reaction is conducted in a thermostated batch reactor, utilizing the commercially available immobilized lipase Lipozyme® 435 in a solvent-free medium. The reaction conversion is determined by an acid number determination and a gas chromatographic analysis. The most optimal result is achieved at a temperature of 80 °C, a biocatalyst concentration of 2.5% (w/w), and a non-stoichiometric substrate relation. A preliminary economic study and the calculation of Green Metrics has established that the operation with a 30% molar excess of acid is the best option to obtain a product with 92.6% purity at a lower cost than the other options and in accordance with the 12 Principles of Green Chemistry. The synthetized diester has a viscosity index of 210, indicating that this new molecule can be used as a biolubricant at extreme temperatures.

Browsing by Subject "Biocatalysis"

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