Genexput: A rapid and standarised method for large genome expansion of Pseudomonas putida

The soil bacteria Pseudomonas putida has gained considerable interest in recent years due to its metabolic complexity, which gives the bacteria huge potential in fields as diverse as bioremediation and bio-based industrial production of chemicals [1]. However, the full exploitation of P. putida potential requires of the development of standarised and hightrouput large genome edditing methods in this bacterium. Actual synbiotools for this purpose in P. putida are still in its infancy and need to be optimised. For instance, well-known state-of-the-art methods such as recombineering and CRISPR-Cas approachs have yet low efficiency in this bacteria [2]. In an attemp to address this important shorcoming in the portfolio of P. putida synbiotools, we have constructed a pSEVA-based [3] library of vectors which allows the genome integration via homologous recombination of large fragments of exogenous DNA. Thereof, loci distributed all along the genome were selected and designed as landing paths for the integration of alien DNA. This way it is possible to add an additional level of gene expression control at genome localization level. We further validated our approach by i) monitoring the expression level of a single GFP reported gene along the genome localization and ii) by expanding the metabolic versatility of P.putida KT2440 towards toluene and m-xylene by integrating in its chromosome the genes encoded in the pWWO plasmid. In summary we provide an efficient toolkit that allows a rapid genome expansion of P. putida while allowing the expression level of the desired transgene

Expanding the enzybiotic toolbox by switching catalytic and cell wall binding domains

Motivation: Bacterial resistance to common antimicrobial therapies (i.e., antibiotics) is reaching alarming levels worldwide [1]. This pushes for the development of alternative antimicrobials, such as bacteriophage-encoded endolysins, also called enzybiotics. This antibacterial approach, rooted in phage therapy, could pose a new and valuable adding to the antimicrobial arsenal, with increased specificity and much lower chances of enabling bacterial escape and resistance mechanisms when compared to antibiotics [2]. Endolysins are usually comprised of a cell wall binding domain (CWBD) and one or several catalytic domains that cleave the bacterial cell wall. Both rational design and domain shuffling have proved to be effective approaches towards the improvement of phage endolysins for therapeutic uses [3]. Thus, the aim of this work is to construct new endolysins active against a range of pathogenic bacteria by switching protein domains.Methods: A new lysin, termed Csl2 was designed by fusing the catalytic lysozyme domain of Cpl-7, encoded by pneumococcal phage Cp-7 [3], and the CWBD from LySMP, encoded by Streptococcus suis phage SMP [4]. The gene encoding the chimeric enzyme was cloned in the expression vector pT7-7, overexpressed in the Escherichia coli strain BL21(DE3) and the protein Csl2 purified following a two-step chromatographic procedure. Relevant biochemical properties of Csl2 were studied, and its bacteriolytic activity was tested against several Gram-positive pathogens.Results: Protein Csl2 was efficiently overexpressed in E. coli BL21(DE3) and purified to >90%. Its secondary structure was similar to that of Cpl-7 according to preliminary circular dichroism experiments. Csl2 was found to be active against several streptococci, mainly from mitis group (namely: S. mitis, S. oralis, S. pseudopneumoniae) and Streptococcus suis from serotypes 2 and 9. The bacteriolytic host range of Csl2 differed from that of parental enzymes, with higher activity against S. suis strains.Conclusions: 1) A new bacteriolytic enzyme, Csl2, was constructed by combining Cpl-7 catalytic domain and LySMP putative Cpl-7-like CWBD.2) Csl2 resembles Cpl-7 biochemically and structurally, but has a different bactericidal spectrum.3) Csl2 is specially active against several S. suis strains, so it might be a candidate for therapy in S. suis infections

30th Anniversary of the “Friends Of Music Society” from Reinosa: Description of a non-formal musical education community project

RESUMEN Los proyectos comunitarios realizados en instituciones musicales, ubicadas en el ámbito educativo no-formal, ofrecen la oportunidad de fomentar una cultura musical básica dentro de la sociedad. Tras analizar conceptualmente las funciones sociales de la educación musical no-formal, este documento describe un proyecto comunitario realizado por la «Asociación Amigos de la Música». Para ello, se analizará un plan de acción compuesto por cuatro propuestas prácticas llevadas a cabo colectivamente durante el 30º aniversario de esta institución.ABSTRACT Community projects in musical institutions in the non-formal education sector, offer the opportunity to develop basic musical culture in society. After analysing conceptually the social functions of the non-formal music education, this document describes a community project developed by the "Friends of Music Society". For this purpose, an action plan consisting of four practical proposals carried out collectively for the 30th anniversary of this institution will be analysed.Grado en Magisterio en Educación Infanti

Engineering biocatalysts for the anaerobic recycling of toxic aromatic hydrocarbons

En: 1st Spanish National Conference on Advances in Materials Recycling and Eco – Energy Madrid, 12-13 November 2009.-- Editors: F. A. López, F. Puertas, F. J. Alguacil and A. Guerrero.-- 3 pages.Azoarcus sp. CIB is a denitrifying betaproteobacterium that uses different aromatic compounds, including toxic hydrocarbons such as toluene and m-xylene, as sole carbon sources, and is susceptible of genetic manipulation. To acquire a global view of all the genetic determinants involved in the anaerobic catabolism of aromatic compounds in strain CIB, and to accelerate and complete our understanding about this anaerobic catabolism, we have performed a genomic survey in the recently sequenced genome of this strain. This information paves the way for a pathway engineering approach within the field of anaerobic degradation of aromatics.Peer reviewe

Modulation of the electroluminescence emission from ZnO/Si NCs/p-Si light-emitting devices via pulsed excitation

In this work, the electroluminescence (EL) emission of zinc oxide (ZnO)/Si nanocrystals (NCs)-based light-emitting devices was studied under pulsed electrical excitation. Both Si NCs and deep-level ZnO defects were found to contribute to the observed EL. Symmetric square voltage pulses (50-μs period) were found to notably enhance EL emission by about one order of magnitude. In addition, the control of the pulse parameters (accumulation and inversion times) was found to modify the emission lineshape, long inversion times (i.e., short accumulation times) suppressing ZnO defects contribution. The EL results were discussed in terms of the recombination dynamics taking place within the ZnO/Si NCs heterostructure, suggesting the excitation mechanism of the luminescent centers via a combination of electron impact, bipolar injection, and sequential carrier injection within their respective conduction regimes

Light-activated electroforming in ITO/ZnO/p-Si resistive switching devices

We report on light-activated electroforming of ZnO/p-Si heterojunction memristors with transparent indium tin oxide as the top electrode. Light-generated electron-hole pairs in the p-type substrate are separated by the external electric field and electrons are injected into the active ZnO layer. The additional application of voltage pulses allows achieving different resistance states that end up in the realization of the low resistance state (LRS). This process requires much less voltage compared to dark conditions, thus avoiding undesired current overshoots and achieving a self-compliant device. The transport mechanisms governing each resistance state are studied and discussed. An evolution from an electrode-limited to a space charge-limited transport is observed along the electroforming process before reaching the LRS, which is ascribed to the progressive formation of conductive paths that consequently induce the growth of conductive nanofilaments through the ZnO layer. This work was financially supported by the Spanish Ministry of Economy and Competitiveness (Project Nos. TEC2012-38540-C02-01 and TEC2016-76849-C2-1-R). O.B. also acknowledges the subprogram "Ayudas para Contratos Predoctorales para la Formación de-Doctores" from the Spanish Ministry of Economy and Competitiveness for economical support. J.L.F. acknowledges the subprogram "Ayudas para la Formación de Profesorado Universitario" (No. FPU16/06257) from the Spanish Ministry of Education, Culture and Sports for economical support. X.P., C.L., and C.G. are grateful to C. Frilay for his expertise in the maintenance of the sputtering setup used for the growth of the ZnO films

Widespread distribution of hepatitis E virus in Spanish pig herds

<p>Abstract</p> <p>Background</p> <p>Hepatitis E virus (HEV) infection is a serious health problem in developing countries and is also increasingly reported in industrialized regions. HEV is considered a zoonotic agent and strains isolated from swine and human sources are genetically similar. Thus, HEV is of increasing importance to both public and animal health. The aim of the present study was to evaluate the distribution of HEV in a large population of pigs from herds located in different autonomous regions throughout Spain.</p> <p>Results</p> <p>The presence of anti-HEV IgG antibodies was analyzed in 1141 swine serum samples (corresponding to 381 pigs younger than 6 months and 760 pigs older than 6 months) collected from 85 herds. Herds were located in 6 provinces in 4 autonomous regions throughout Spain. At least one pig tested positive for anti-HEV IgG in over 80% of herds. Of individual pigs, 20.4% (233/1141) were positive for anti-HEV IgG, with the prevalence being higher in adult pigs than in those under 6 months (30.2% <it>vs. </it>15.5%). A subset of serum samples taken at 2- to 5-week intervals showed that seroprevalence dropped between 3 and 11 weeks of age, and then rose significantly by the 15th week. Pigs were also examined for the presence of HEV-RNA by RT-PCR. Of pigs tested for the presence of HEV-RNA 18.8% (64/341) were positive, with at least one pig in almost half of the herds testing positive. HEV-RNA amplicons from several positive pigs were sequenced and all were of genotype 3.</p> <p>Conclusions</p> <p>HEV was found to be widely distributed among swine farms across Spain, with the prevalence being highest among animals older than 6 months. These results indicate that HEV infection either is or is likely to become endemic in the Spanish swine population.</p

Toward RGB LEDs based on rare earth-doped ZnO

By using ZnO thin films doped with Ce, Tb or Eu, deposited via radiofrequency magnetron sputtering, we have developed monochromatic (blue, green and red, respectively) light emitting devices (LEDs). The rare earth ions introduced with doping rates lower than 2% exhibit narrow and intense emission peaks due to electronic transitions in relaxation processes induced after electrical excitation. This study proves zinc oxide to be a good host for these elements, its high conductivity and optical transparency in the visible range being as well exploited as top transparent electrode. After structural characterization of the different doped layers, a device structure with intense electroluminescence is presented, modeled, and electrically and optically characterized. The different emission spectra obtained are compared in a chromatic diagram, providing a reference for future works with similar devices. The results hereby presented demonstrate three operating monochromatic LEDs, as well as a combination of the three species into another one, with a simply-designed structure compatible with current Si technology and demonstrating an integrated red-green-blue emission

Photoelectrical reading in ZnO/Si NCs/p-Si resistive switching devices

The increasing need for efficient memories with integrated functionalities in a single device has led the electronics community to investigate and develop different materials for resistive switching (RS) applications. Among these materials, the well-known Si nanocrystals (NCs) have demonstrated to exhibit RS properties, which add to the wealth of phenomena that have been studied on this model material platform. In this work, we present ZnO/Si NCs/p-Si resistive switching devices whose resistance state can be electrically read at 0 V under the application of low-power monochromatic illumination. The presented effect is studied in terms of the inner structural processes and electronic physics of the device. In particular, the creation of conductive filaments through the Si NC multilayers induces a low-resistance path for photogenerated carriers to get extracted from the device, whereas in the pristine state charge extraction is strongly quenched due to the insulating nature of the NC-embedding SiO2 matrix. In addition, spectral inspection of the generated photocurrent allowed unveiling the role of Si NCs in the reported effect. Overall, the hereby shown results pave the way to obtain memories whose RS state can be read under low-power conditions

La importancia de los intereses académicos en la política científica y tecnológica catalana

Publicado en: 'Papers: Revista de Sociología', 70: 11-40, 2003Este artículo describe la emergencia y orientación de las políticas de I+D e innovación en Cataluña. Se analizan cuáles son los factores más influyentes en la orientación de estas políticas y, en definitiva, en las opciones políticas que se toman. La política de ciencia y tecnología desarrollada por el gobierno regional catalán desde principios de los años ochenta ha sido una política en la que, a pesar de las preferencias manifestadas en el discurso político, ha predominado un modelo de política académico sobre el de orientación empresarial. Asimismo, en términos organizativos e institucionales, en la Administración autonómica, la política científica ha estado separada y diferenciada de la política tecnológica a pesar del diseño inicial de instituciones interdepartamentales. La principal razón de que la política de I+D catalana no siguiera un modelo más industrial, ligado al mundo empresarial, fue la presión que ejercieron las universidades catalanas para que, tanto el diseño institucional como el contenido de la política se adaptara a sus necesidades. La trayectoria académica previa de los gestores también contribuyó a la reorientación de las preferencias políticas. A pesar de la importancia de las empresas catalanas en la I+D, éstas no se movilizaron ni presionaron a los gobiernos suficientemente. Analíticamente, este caso ilustra cómo la sola creación política de instituciones no garantiza la realización de las preferencias políticas. También pone de manifiesto cómo el horizonte temporal de la toma de decisiones gubernamental tiene un efecto en las expectativas de los actores, que desarrollan procesos de aprendizaje a partir de las experiencias en arenas políticas similares a otros niveles. Por último, destaca la importancia del poder en las instituciones de gestión en este tipo de política distributiva.Peer reviewe