Valorization of soda lignin from wheat straw solid-state fermentation: Production of oleogels.

This work describes the solid-state fermentation(SSF) of wheat straw with Streptomyces sp. MDG147 and further soda-pulping process to obtain wheat straw soda lignins(WSLs). Subsequently, these WSLs were NCO-functionalized with 1,6-hexamethylene diisocyanate and then dispersed in castor oil to achieve stable oleogels. The WSLs were characterized using standard analytical methods, gel permeation chromatography, Fourier transform infrared spectroscopy,differential scanning calorimetry, and thermogravimetric analysis. Rheological properties of oleogels were determinedby means of small-amplitude oscillatory shear and viscous flow measurements. The enzymatic profile and production oflignin−carbohydrate complexes were recorded along the growth time of Streptomyces, whose life cycle was achieved after 7 days. NCO-functionalized WSL was able to chemically interact with castor oil via urethane bonding, providing oleogels with suitable rheological characteristics. Linear viscoelastic functions and viscosity values of oleogels were higher when wheat straw was submitted to SSF using Streptomyces, turning out in stronger oleogels.Ministerio de Economía, Industria y Competitivida

Genetic Polymorphisms in VEGFR Coding Genes (FLT1/KDR) on Ranibizumab Response in High Myopia and Choroidal Neovascularization Patients

A severe form of myopia defined as pathologic/high myopia is the main cause of visual impairment and one of the most frequent causes of blindness worldwide. It is characterized by at least 6 diopters or axial length (AL) of eyeball > 26 mm and choroidal neovascularization (CNV) in 5 to 10% of cases. Ranibizumab is a humanized recombinant monoclonal antibody fragment targeted against human vascular endothelial growth factor A (VEGF-A) used in the treatment of CNV. It acts by preventing VEGF-A from interacting with its receptors (VEGFR-1 and -2) encoded by the FLT1 and KDR genes. Several studies found that the KDR and FLT1 genotypes may represent predictive determinants of efficacy in ranibizumab-treated neovascular age-related macular degeneration (nAMD) patients. We performed a retrospective study to evaluate the association of single nucleotide polymorphisms (SNPs) in VEGFR coding genes with the response rate to ranibizumab in patients with high myopia and CNV. In the association study of genotypes in FLT1 with the response to ranibizumab, we found a significant association between two FLT1 variants (rs9582036, rs7993418) with ranibizumab efficacy at the 12-month follow-up. About the KDR gene, we found that two KDR variants (rs2305948, rs2071559) are associated with best-corrected visual acuity (BCVA) improvement and KDR (rs2239702) is associated with lower rates of BCVA worsening considering a 12-month follow-up period

¿Qué queda de mí?

Este libro es una reclamación a quienes hemos sido, somos o seremos docentes. A quienes no hemos respetado a las personas que se han puesto junto a nosotros y nosotras, confiando su bien más preciado: la libertad. Estas páginas denuncian cada vez que convertimos una visión en la visión, una emoción en la emoción, un saber en el saber, un comportamiento en el comportamiento. Es un grito contra la imposición, la normalización, la neutralización y la universalización de una perspectiva particular. Una pugna contra cada proceso que no se ha conectado con las vidas de los aprendices. Un texto colaborativo realizado por alumnado de Educación y Cambio Social en el Grado en Educación Infantil de la Universidad de Málaga y coordinado por Ignacio Calderón Almendros

Caracterización y función biológica de la lacasa producida por "Streptomyces ipomea" CECT 3341 : aprovechamiento de su potencial oxidativo para la degradación de contaminantes ambientales

Las lacasas son enzimas con actividad fenoloxidasa, pertenecientes al grupo de las oxidorreductasas multicobre caracterizadas por poseer átomos de cobre en su centro activo. Catalizan la oxidación monoelectrónica de una gran variedad de sustancias fenólicas y aminas aromáticas con el oxígeno molecular como aceptor final de electrones. Son enzimas ampliamente distribuidas en la naturaleza y han sido descritas en hongos, plantas, insectos, bacterias e incluso en arqueas. El interés actual de estas enzimas se debe a su gran potencial para ser utilizadas con fines biotecnológicos y/o medioambientales. En este trabajo se ha llevado a cabo en primer lugar, la producción, purificación y caracterización físico-química y cinética de la lacasa recombinante SilA de la cepa Streptomyces ipomoea CECT 3341. Asimismo, se ha analizado la capacidad oxidativa de la enzima en distintos sistemas lacasa-mediador y del microorganismo mediante la inducción de radicales hidroxilo a través de ciclos redox de quinonas. Por último, se ha abordado el estudio de la función biológica de SilA en el microorganismo productor. La estimación del potencial redox de la enzima puso de manifiesto que se trata de una lacasa de potencial redox bajo, al igual que se ha descrito para otras lacasas bacterianas. SilA mostró una moderada estabilidad frente a los agentes caotrópicos ensayados (temperatura y cloruro de guanidinio), demostrándose que el estado nativo de la enzima es más estable que el desnaturalizado. El ensayo de la termoestabilidad cinética permitió determinar la vida media de la enzima que se estimó en 1,3 horas a 95 ºC. Por otro lado, los ensayos conducentes a la elucidación de la estructura tridimensional de SilA no resultaron concluyentes por la imposibilidad de cristalizar la proteína debido, probablemente, a la presencia de dominios hidrofóbicos en el exterior de su estructura, lo que causó interferencias con el procedimiento analítico utilizado. No obstante, mediante comparación de la secuencia de SilA con las secuencias de otras lacasas bacterianas publicadas en las bases de datos, se pudo obtener un modelo teórico tridimensional de la estructura de la lacasa, que permitió elucidar la presencia de dos dominios de tipo cupredoxina, al igual que se ha descrito para otras lacasas de estreptomicetos. La capacidad oxidativa de SilA se puso de manifiesto en actuación conjunta con distintos mediadores frente a tintes textiles de tipo azo y distintos fármacos (fluoroquinolonas y Carbamazepina), obteniéndose los mejores resultados cuando se utilizaron como mediadores la acetosiringona y/o el siringato de metilo, siendo la concentración del mediador y la temperatura factores condicionantes para la eficacia del sistema. Asimismo, se ha demostrado que el micelio de S. ipomoea es capaz de generar radicales hidroxilo gracias a la presencia de la lacasa SilA y de actividad quinona reductasa, los cuales a su vez han resultado muy efectivos en la degradación de los tintes textiles y de los fármacos mencionados. Es importante destacar que el micelio de S. ipomoea permaneció viable tras 24 horas de producción inducida de radicales hidroxilo, lo que avala la idoneidad de este microorganismo para ser utilizado en procesos de biorremediación. El análisis de la toxicidad de los contaminantes de partida y de los productos de degradación obtenidos por ambos sistemas oxidativos demostró que, en algún caso, la toxicidad de los productos de degradación obtenidos era superior a la de los contaminantes de partida, de lo que se infiere la necesidad de llevar a cabo dichos estudios utilizando distintos sistemas de análisis para poder validar los resultados. Por último, con objeto de elucidar la posible función biológica de la lacasa SilA, se llevó a cabo la obtención de un mutante de S. ipomoea no productor de actividad lacasa, mediante disrupción génica. La obtención de dicho mutante permitió conocer la implicación de dicha enzima en la tolerancia al cobre y en la solubilización de la lignina de paja de trigo, funciones que corroboran el interés biotecnológico de la misma

Gene disruption and further complementation of gene silA

Obtention of a laccase-negative mutant of <i>Streptomyces ipomoeae</i> by gene disruption with the insertion of an apramycin-resistant cassette. Restoration of the laccase activity in the mutant strain by complementation with the original <i>silA</i> gene inserted into the pEM4T plasmid

Assessment of Sustainability of Bio Treated Lignocellulose-Based Oleogels

The development of biological strategies to obtain new high-added value biopolymers from lignocellulosic biomass is a current challenge for scientific community. This study evaluates the biodegradability and ecotoxicity of new formulated oleogels obtained from fermented agricultural residues with Streptomyces, previously reported to show improved rheological and tribological characteristics compared to commercial mineral lubricants. Both new oleogels exhibited higher biodegradation rates than the commercial grease. Classical ecotoxicological bioassays using eukaryotic organisms (Lactuca sativa, Caenorhabditis elegans) showed that the toxic impact of the produced bio-lubricants was almost negligible and comparable to the commercial grease for the target organisms. In addition, high throughput molecular techniques using emerging next-generation DNAsequencing technologies (NGS) were applied to study the structural changes of lubricant-exposed microbial populations of a standard soil. Results obtained showed that disposal of biomass-based lubricants in the soil environment did not substantially modify the structure and phylogenetic composition of the microbiome. These findings point out the feasibility and sustainability, in terms of biodegradability and eco-safety, of the new bio-lubricants in comparison with commercial mineral greases. This technology entails a promising biological strategy to replace fossil and non-renewable raw materials as well as to obtain useful biopolymers from agricultural residues with potential for large-scale applications

Cellulose Pulp- and Castor Oil-Based Polyurethanes for Lubricating Applications: Influence of Streptomyces Action on Barley and Wheat Straws

The replacement of mineral oils and non-renewable gelling agents is an imperative requirement for the lubricant industry in the near future. In this framework, cellulose pulp and castor oil are proposed as sustainable substitutes for these components. Biological treatment has been explored and evaluated to enhance the dispersing and thickening properties of cellulose pulp in oil media. Streptomyces sp. MDG147 and MDG301 strains were employed to modify agricultural wheat and barley straw residues from which cellulose pulp was obtained afterwards. In addition, an environmentally friendly process for the production of cellulose-pulp-/castor-oil-based polyurethanes was applied, in which neither catalysts nor harmful solvents were used, resulting in chemical oleogels. These oleogels were rheologically and tribologically characterized to evaluate their performance as lubricating greases. The enzymatic activity pattern developed was dependent on the raw material, the strain type, and the temperature, influencing the cellulose pulp’s composition, polymerization degree, and crystallinity. These modified characteristics tuned the rheological behavior of the different oleogels, providing a beneficial range of viscoelastic responses and viscosity values that were generally favored by the Streptomyces action. Furthermore, the friction coefficient and dimensions of wear scars measured in a tribological contact were comparable to, or even lower than, those found with commercial and other bio-based lubricating greases that have previously been studied

Laccase SilA from Streptomyces ipomoeae CECT 3341, a key enzyme for the degradation of lignin from agricultural residues?

15 páginas.-- 4 referencias.-- 37 referenciasThe role of laccase SilA produced by Streptomyces ipomoeae CECT 3341 in lignocellulose degradation was investigated. A comparison of the properties and activities of a laccase-negative mutant strain (SilA-) with that of the wild-type was studied in terms of their ability to degrade lignin from grass lignocellulose. The yields of solubilized lignin (acid precipitable polymeric lignin, APPL) obtained from wheat straw by both strains in Solid State Fermentation (SSF) conditions demonstrated the importance of SilA laccase in lignin degradation with the wild-type showing 5-fold more APPL produced compared with the mutant strain (SilA-). Analytical pyrolysis and FT-IR (Fourier Transform Infrared Spectroscopy) confirmed that the APPL obtained from the substrate fermented by wild-type strain was dominated by lignin derived methoxyphenols whereas those from SilA- and control APPLs were composed mainly of polysaccharides. This is the first report highlighting the role of this laccase in lignin degradation. © 2017 Blánquez et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.This study was funded in part by projects CTQ2014-56038-C3-2-R and CGL2016-78937-R (INTERCARBON) from the Spanish Ministry for Economy and Competitiveness. N.T Jiménez Morillo acknowledges a FPI research grant (BES-2013-062573) and A. Blánquez is awarded with a grant from the project CTQ2014-56038-C3-2-R.Peer reviewe

Genetic Polymorphisms Affecting Ranibizumab Response in High Myopia Patients

This article includes results from a doctoral thesis being developed linked to the doctoral program in Pharmacy at the University of Granada, to whom we thank for their collaboration. We also would like to thank patients for their consent and collaboration in the study; nurses and personnel of the ophthalmology unit in the “Hospital San Cecilio” (Granada) for their kindly collaboration in the recruitment of patients; and personnel of the Genomics Unit in the Pfizer—University of Granada—Junta de Andalucía Centre for Genomics and Oncological Research (GENYO) for their excellent technical assistance.High myopia is an ophthalmic pathology that affects half of the young adults in the United States and Europe and it is predicted that a third of the world's population could be nearsighted at the end of this decade. It is characterized by at least 6 diopters or axial length > 26 mm and, choroidal neovascularization (CNV) in 5 to 11% of cases. Ranibizumab is a recombinant humanized monoclonal antibody fragment. It is an anti-vascular endothelial growth factor (anti-VEGF) drug used in the treatment of CNV. Many genetic polymorphisms have been associated with interindividual differences in the response to ranibizumab, but these associations were not yet assessed among patients with high myopia and CNV. We performed a retrospective study assessing the association of genetic polymorphisms with response to ranibizumab in patients with CNV secondary to high myopia (mCNV). We included genetic polymorphisms previously associated with the response to drugs used in CNV patients (bevacizumab, ranibizumab, aflibercept, and photodynamic therapy (PDT)). We also included genetic variants in the VEGFA gene. Based on our results, ARMS2 (rs10490924) and CFH (rs1061170) are associated with response to ranibizumab in high myopia patients; and, included VEGFA genetic polymorphisms are not associated with ranibizumab response in our population but might be related to a higher risk of CNV

Cellulose Pulp- and Castor Oil-Based Polyurethanes for Lubricating Applications: Influence of Streptomyces Action on Barley and Wheat Straws

The replacement of mineral oils and non-renewable gelling agents is an imperative requirement for the lubricant industry in the near future. In this framework, cellulose pulp and castor oil are proposed as sustainable substitutes for these components. Biological treatment has been explored and evaluated to enhance the dispersing and thickening properties of cellulose pulp in oil media. Streptomyces sp. MDG147 and MDG301 strains were employed to modify agricultural wheat and barley straw residues from which cellulose pulp was obtained afterwards. In addition, an environmentally friendly process for the production of cellulose-pulp-/castor-oil-based polyurethanes was applied, in which neither catalysts nor harmful solvents were used, resulting in chemical oleogels. These oleogels were rheologically and tribologically characterized to evaluate their performance as lubricating greases. The enzymatic activity pattern developed was dependent on the raw material, the strain type, and the temperature, influencing the cellulose pulp&rsquo;s composition, polymerization degree, and crystallinity. These modified characteristics tuned the rheological behavior of the different oleogels, providing a beneficial range of viscoelastic responses and viscosity values that were generally favored by the Streptomyces action. Furthermore, the friction coefficient and dimensions of wear scars measured in a tribological contact were comparable to, or even lower than, those found with commercial and other bio-based lubricating greases that have previously been studied