34 research outputs found

    Dynamical characterization of the 6/1 mean motion resonance between Quaoar's ring and Weywot

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    Recently, it has been reported the discovery of a dense ring around the trans-Neptunian object 50000 Quaoar. The ring particles seem to be very close to the 6/1 mean motion resonance with Weywot, the only known satellite in the system. In this work we investigate the dynamical environment in the close vicinity of the 6/1 orbital resonance in the context of the restricted three body problem. We aim to analyze whether, in view of observational constraints, the ring could be effectively evolving in resonant motion with the satellite. Through the technique of dynamical maps we identify and characterize the 6/1 mean motion resonance, finding that the main location of the resonance deviates by only 2929 km from the central part of the ring. This difference lies within the 3σ\sigma confidence level, considering the uncertainties in the observational parameters. We also show that the Weywot's eccentricity plays a significant role in the dynamical structure of the 6/1 resonance. The results show that the resonance width is smaller than the estimated ring's width. Under assumption of a ring with eccentricity smaller than 0.05, clumping of test particles appears at the position of the different resonant multiplets, considering the nominal value of Weywot's eccentricity. This is in agreement with observations, which indicate that the estimated resonance width (\leq 10 km) is comparable with the narrow and dense arc of material within Quaoar's ring. Our results may be an indicative that the 6/1 resonance resonance plays a key role in confining the arc ring.Comment: Accepted for publication in MNRA

    Effects of foliar fertilization of a biostimulant obtained from chicken feathers on maize yield

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    Due to the important contribution that it makes to human nutrition, maize is one of the most widely-consumed cereals in the world. There is, therefore, high demand for fertilizers that will maintain maize production at both high yield and quality levels. The objective of this work was to study the effect of foliar fertilization using a biostimulant, obtained by enzymatic hydrolysis from chicken feathers, on the productivity and quality of maize crops (Zea mays, L. cv PR32W86 Pioneer), located in Trujillanos (Extremadura, Spain), over two consecutive seasons. Foliar biostimulant/biofertilizer was applied three times each season and at two rates (3.6 and 7.2 l ha−1). At the higher rate and for both seasons, foliar fertilization significantly increased the leaf concentrations of macro- and micronutrients, while grain protein content and yield increased by 26% and 14%. These results suggest that the foliar use of this biostimulant could be of great interest to the farmer for improving both maize crop yield and quality.Ministerio de Economia y Competitividad CTM2015-64354-C3-1-RMinisterio de Economia y Competitividad CTM2015-64354-C3-3-RJunta de Andalucía RNM-2011-788

    Diseño y escalado de un proceso biotecnológico de valorización de suero lácteo mediante la producción de ácido láctico

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    Motivación: La industria quesera genera grandes cantidades de suero lácteo, líquido que queda tras la separación de la grasa y la caseína de la leche en el proceso de producción del queso. El suero lácteo es uno de los principales subproductos generados a nivel mundial, y debido a sus altas cargas de DBO y DQO de 30.000-50.000 y 60.000-80.000 ppm respectivamente, es proclive a generar graves problemas de contaminación medioambiental estando prohibido su vertido desde 1996 por el Consejo de la UE, que lo cataloga como un residuo contaminante. Estos motivos exigen a las queserías la implementación de costosos sistemas de tratamiento de residuos a los que muchas de ellas no pueden hacer frente. Por otra parte es necesario destacar que el suero conserva cerca del 50% de los nutrientes de la leche. Contiene cantidades significativas de lactosa, así como proteínas, vitaminas hidrosolubles y minerales. Esta interesante composición ha impulsado multitud de investigaciones encaminadas a la valorización de este subproducto. El objetivo de este proyecto es el diseño de una biorrefinería que permita una valorización total de las fracciones mayoritarias del suero (proteína, grasa, lactosa y sales) con la principal finalidad de producir ácido láctico que es el ácido carboxílico con mayor presencia debido a su versatilidad de uso en las industrias farmacéuticas, alimentaria y química. En una segunda fase del proyecto, el ácido láctico será usado como "building blocks" en la producción de PLA. Métodos: Se han realizado fermentaciones a escala de laboratorio en un fermentador de 2 l para optimizar los parámetros de fermentación, con vistas a ampliar la escala de trabajo en una segunda etapa del proyecto. Mediante un proceso que combina la microfiltración y una tecnología de extracción por solventes conseguimos purificar el ácido láctico del suero fermentado. Resultados: Se ha logrado la conversión completa de lactosa a ácido láctico en las fermentaciones, obteniendo entre 40 y 50 g de ácido láctico por litro de suero fermentado. Mediante la tecnología de purificación desarrollada hemos conseguido obtener ácido láctico al 90%. Conclusiones: Este proyecto se plantea como una posible vía de valorización total del suero lácteo como alternativa a los costosos tratamientos que requieren su vertido. Hemos diseñado un proceso de purificación de ácido láctico económicamente viable y ecosostenible, con un reaprovechamiento total de los subproductos generado

    Biomethane production improvement by enzymatic pretreatments and enhancers of sewage sludge anaerobic digestion

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    Enzymatic hydrolysis is recognised as an effective pre-treatment for increasing biodegradability of sludge. In this work, isolated commercial enzymes as well as in-situ enzymes producer bacteria were used respectively as enhancers and pre-treatments of sewage sludge. Biodegradability of sample as well as biomethane potential production were studied. Results showed that depuration efficiencies in terms of CODs (73.5-85.5 %) and TVS (28.5-42.7 %) were more than twice the control value. In addition, pre-treated samples as well as enhanced samples with enzymes generated more biomethane than control. The optimal ones, were those with the isolated proteases (P) and with bacteria (Bacillus licheniformis) treatment in-situ (F), producing a total volume of 72.4 ± 2.62 ml CH4 and 114 ml ± 0.46 CH4, respectively, increasing the biogas volume in 3.65 and 5.77 times respectively compared with control

    Design of a biofertilizer based on okara fermentated with Bacillus licheniformis

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    Bacillus licheniformis is a Gram-positive, soil bacterium used in the biotechnology industry to manufacture industrial enzymes including several proteases, amylase, lipases, chitinases, etc. These enzymes have a wide range of application in food and detergent industry. However, this organism may have other applications in the environmental field, thus marketed biological products for agriculture with biofertilizer capacity have been formulated based on Bacillus licheniformis and/or isolated extracellular enzymes that contribute to nutrient cycling in nature, which is responsible for the biofertilizer function. The objective of this work is to obtain a new product based on Bacillus licheniformis and hydrolytic enzymes with environmental applications. In order to obtain this product we have chosen an organic byproduct of low economic value, the okara obtained in large scale in the production of soy milk as fermentation source. The okara has also a great potential as a fertilizer because it has high concentrations of organic nitrogen and phosphorus, but has a problem because it is poorly bioavailable because it is insoluble and proteins and carbohydrates are high molecular weight. Briefly, the optimal fermentation conditions (pH, temperature, substrate concentration) has been determined, which has led to obtain a new product with agronomic/environmental applications, with three important features: 1. Total solubility, biopolymers have been hydrolysed (peptides, glucose, fatty acid) 2. High production of hydrolytic enzymes (protease, amylase and lipase) 3. High bacterial concentration (Bacillus licheniformis) Chemical and microbiological characterization of this new product has been made, and its biofertilization activity has been tested

    Obtaining from grape pomace an enzymatic extract with anti-inflammatory properties

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    Grape pomace, a winemaking industry by-product, is a rich source of bioactive dietary compounds. Using proteases we have developed an enzymatic process for obtaining a water-soluble extract (GP-EE) that contains biomolecules such as peptides, carbohydrates, lipids and polyphenols in soluble form. Of especial interest is its high polyphenol content (12 %), of which 77 % are flavonoids and 33 % are phenolic acids. The present study evaluates in vitro the potential anti-inflammatory effect of GP-EE by monitoring the expression of inflammatory molecules on N13 microglia cells stimulated with lipopolysaccharide (LPS). GP-EE decreases the mRNA levels of the inflammatory molecules studied. The molecules under study were as follows: inducible nitric oxide synthase (iNOS), tumor necrosis factor- α (TNF-α), interleukin-1β (IL-1β), the ionized calcium binding adaptor molecule-1(Iba-1) and the Toll like receptor-4 (TLR-4), as well as the iNOS protein level in LPS-stimulated microglia. Our findings suggest that, as a result of its ability to regulate excessive microglial activation, GP-EE possesses antiinflammatory properties. Therefore, acting as a chemopreventive agent, it may be of therapeutic interest in neurodegenerative diseases involving neuroinflammation. We can, therefore, propose GP-EE as a useful natural extract and one that would be beneficial to apply in the field of functional food

    Protease technology for obtaining a soy pulp extract enriched in bioactive compounds: isoflavones and peptides

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    This work presents a new bioprocess process for the extraction of bioactive components from soy pulp by-product (okara) using an enzymatic technology that was compared to a conventional water extraction. Okara is rich in fiber, fat, protein, and bioactive compounds such as isoflavones but its low solubility hampers the use in food and fertilizer industry. After the enzymatic attack with endoproteases half of the original insoluble proteins were converted into soluble peptides. Linked to this process occured the solubilization of isoflavones trapped in the insoluble protein matrix. We were able to extract up to 62.5% of the total isoflavones content, specially aglycones, the more bioactive isoflavone forms, whose values rose 9.12 times. This was probably due to the increased solubilization and interconversion from the original isoflavones. In conclusion, our process resulted in the formulation of a new functional product rich in aglycones and bioactive peptides with higher antioxidant potency than the original source. Therefore, we propose that the enzymatic extraction of okara bioactive compounds is an advantageous tool to replace conventional extraction

    Effect of pH on the production of hydrolytic enzymes of industrial interest by Bacillus licheniformis using sewage sludge as a low-cost culture médium

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    Management of sewage sludge has become a topic of increasing importance. This is because the treatment and final destination of these wastes are not growing at the same rate at which generated what is necessary to add the limited storage capacity of wastewater treatment plants or waste transfer centers. Current policies of different governments aims, among others, promote proecological management of sewage sludge, replacing traditional methods by new methods that lead to their stabilization and safe recycling. These methods can lead to the recovery of valuable raw materials from potentially dangerous others in order to permit their use in agriculture, industry or energy production. Moreover, exists a great enzyme market, mainly those with hydrolytic activities such as proteases, lipases or cellulases. Although its use has many advantages, the competitiveness of the enzymes compared with chemicals is limited by its high production costs. The use of a less expensive culture media and the stimulation of the production of these enzymes can significantly reduce production costs. Therefore, the use of tertiary materials as alternative substrates, available in large quantities and at lower cost, is an interesting option. In this work we have studied the effect of pH on the fermentation of sewage sludge by Bacillus licheniformis, a hydrolytic enzymes producer microorganism, in order to obtain several products for specific agronomic applications
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