Utilización de lipasas en la producción de un nuevo tipo de biodiesel que evita la generación de glicerol

Los altos precios de los combustibles derivados del petróleo están ocasionando una intensificación de la investigación de los métodos de producción de los biocombustibles, con la idea de optimizar la producción de combustibles de origen no fósil para reducir la dependencia del petróleo. En los actuales procesos de producción de biodiesel, con independencia de la escala o el tipo de proceso utilizado (continuo o discontinuo), se emplean de forma casi generalizada catalizadores en fase homogénea, como KOH. Son procesos que, además de presentar los inconvenientes intrínsecos de la catálisis homogénea, generan glicerina de baja calidad, que ha de ser tratada como residuo al caer su precio cada vez más por los excedentes que se producen. Una de las posibles soluciones a este problema y objetivo principal de esta tesis doctoral, es la producción de un nuevo tipo de biodiesel que integre la glicerina en forma de mono y diglicéridos. De esta forma se evitaría el problema de la obtención de glicerina y se incrementaría asimismo el rendimiento atómico del proceso, ya que toda la materia prima reaccionante se transformaría en biodiesel. La utilización de lipasas 1,3-regioespecíficas en condiciones óptimas, permite llevar a cabo la reacción de transesterificación de un mol de triglicérido (TG) con etanol para obtener dos moles de éster etílico y un mol de monoglicérido (MG), evitándose así la obtención de glicerina. En la actualidad, la glicerina se considera prácticamente como un residuo o un producto muy poco rentable, que además puede ocasionar graves problemas en los motores si no ha sido eliminada totalmente de la mezcla empleada como biocombustible. La aplicación de éste método enzimático simplificaría enormemente el proceso de producción, ahorrando el gran consumo de agua necesario para eliminar la glicerina, tal como se produce con la utilización del método estándar. La viabilidad de utilización de este método, así como su simplicidad, queda demostrada en esta memoria, así como en las publicaciones científicas derivadas de ella, y en más de una decena de comunicaciones a congresos

Evidence of Mycobacterium avium subsp. paratuberculosis (MAP) infection in huemul deer (Hippocamelus bisulcus) in patagonian fjords

In the Chilean coastal Patagonia, fourteen wild deer huemul faecal pellet samples were collected and cultured for Mycobacterium avium subsp. paratuberculosis detection. Six samples were positive, but only one was able to show a molecular type similar to the most common strain reported for cattle in Chile

New Metformin–Citric Acid Pharmaceutical Molecular Salt: Improving Metformin Physicochemical Properties

Crystal engineering and, more specifically, the development of multicomponent materials has become an effective technique to rationally modify important physicochemical properties of solids, such as solubility and thermal stability. In this work, in order to overcome some of the problems that metformin has as a pharmaceutical, a new metformin base salt with citric acid (MTF–CIT) has been developed, which improves the thermal stability and solubility (two-fold) compared to metformin base (MTF). A complete characterization of the new crystalline form through PXRD, DSC, SCXRD, and FT–IR was conducted to ensure the purity of the new phase and provide a comprehensive view of its physicochemical behavior, thus correlating the improvement in stability and solubility with the crystal structure. The MTF–CIT salt crystallizes in the monoclinic P21/c1 spacegroup with z0 = 1. Intermolecular interactions found in MTF–CIT structure and simulated crystal morphology suggest a steric protection effect on the metformin ion that leads to the enhancement of stability in several orders of magnitude compared with MTF, as well as an improvement in solubility due to the exposition of polar groups in the biggest facets, making this new multicomponent salt a promising pharmaceutical solid.MCIU/AEI/FEDER, UE PGC2018-102047-B-I00FEDER-Universidad de Granada, Spain B-FQM-478-UGR2

Rational Coformer Selection in the Development of 6-Propyl-2-thiouracil Pharmaceutical Cocrystals

The following supporting information can be downloaded at: https://www. mdpi.com/article/10.3390/ph16030370/s1This research was funded by Project B-FQM-478-UGR20 (FEDER-Universidad de Granada, Spain). A.F. thanks MICIU/AEI of Spain (project PID2020-115637GB-I00, FEDER) for financial support.Pharmaceutical multicomponent solids have proved to efficiently modulate the physico- chemical properties of active pharmaceutical ingredients. In this context, polyphenols are interesting coformers for designing pharmaceutical cocrystals due to their wide safety profile and interesting antioxidant properties. The novel 6-propyl-2-thiouracil multicomponent solids have been obtained by mechanochemical synthesis and fully characterized by powder and single-crystal X-ray diffraction methods. The analysis of supramolecular synthons has been further performed with computational methods, with both results revealing a robust supramolecular organization influenced by the different positions of the hydroxyl groups within the polyphenolic coformers. All novel 6-propyl-2-thiouracil cocrystals show an enhanced solubility profile, but unfortunately, their thermodynamic stability in aqueous media is limited to 24 h.FEDER-Universidad de Granada, Spain B-FQM-478-UGR20Spanish Government PID2020-115637GB-I0

Production of a biodiesel-like biofuel without glycerol generation, by using Novozym 435, an immobilized Candida antarctica lipase

Background: Novozym 435, a commercial lipase from Candida antarctica, recombinant, expressed in Aspergillus niger, immobilized on macroporous acrylic resin, has been already described in the obtention of biodiesel. It is here evaluated in the production of a new biofuel that integrates the glycerol as monoglyceride (MG) together with two fatty acid ethyl esters (FAEE) molecules by the application of 1,3-selective lipases in the ethanolysis reaction of sunflower oil. Results: Response surface methodology (RSM) is employed to estimate the effects of main reaction. Optimum conditions for the viscosity, selectivity, and conversion were determined using a multifactorial design of experiments with three factors run by the software Stat Graphics version XV.I. The selected experimental parameters were reaction temperature, oil/ethanol ratio and alkaline environment. On the basis of RSM analysis, the optimum conditions for synthesis were 1/6 oil/EtOH molar ratio, 30°C, and 12.5 μl of NaOH 10 N aqueous solutions, higher stirring than 300 rpm, for 2 h and 0.5 g of biocatalyst. Conclusions: These obtained results have proven a very good efficiency of the biocatalyst in the studied selective process. Furthermore, it was allowed sixteen times the successive reuse of the biocatalyst with good performanc

Biocatalytic behaviour of immobilized Rhizopus oryzae lipase in the 1,3-selective ethanolysis of sunflower oil to obtain a biofuel similar to biodiesel

A new biofuel similar to biodiesel was obtained in the 1,3-selective transesterification reaction of sunflower oil with ethanol using as biocatalyst a Rhizopus oryzae lipase (ROL) immobilized on Sepiolite, an inorganic support. The studied lipase was a low cost powdered enzyme preparation, Biolipase-R, from Biocon-Spain, a multipurpose additive used in food industry. In this respect, it is developed a study to optimize the immobilization procedure of these lipases on Sepiolite. Covalent immobilization was achieved by the development of an inorganic-organic hybrid linker formed by a functionalized hydrocarbon chain with a pendant benzaldehyde, bonded to the AlPO4 support surface. Thus, the covalent immobilization of lipases on amorphous AlPO 4/sepiolite (20/80 wt %) support was evaluated by using two different linkers (p-hydroxybenzaldehyde and benzylamine-terephthalic aldehyde, respectively). Besides, the catalytic behavior of lipases after physical adsorption on the demineralized sepiolite was also evaluated. Obtained results indicated that covalent immobilization with the p-hydroxybenzaldehyde linker gave the best biocatalytic behavior. Thus, this covalently immobilized lipase showed a remarkable stability as well as an excellent capacity of reutilization (more than five successive reuses) without a significant loss of its initial catalytic activity. This could allow a more efficient fabrication of biodiesel minimizing the glycerol waste production. © 2014 by the authors.Grants from the Spanish Ministry of Economy and Competitiveness (Project ENE 2011-27017), Spanish Ministry of Education and Science (Projects CTQ2010-18126 and CTQ2011-28954-C02-02), FEDER funds and Junta de Andalucía FQM 0191, PO8-RMN-03515 and P11-TEP-7723 are gratefully acknowledged by the authors. We are also gratefully to Biocon®-Spain, for the kindly supply of the BIOLIPASE-R®. We acknowledge support by the CSIC Open Access Publication Initiative through its Unit of Information Resources for Research (URICI)Peer Reviewe