Post-transcriptional control in the regulation of polyhydroxyalkanoates synthesis

Funding Information: Funding: Work at ITQB NOVA was financially supported by the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie ID: 867437, and projects UIDB/04612/2020 and UIDP/04612/2020 (Molecular, Structural and Cellular Microbiology), funded by FEDER through COMPETE 2020—Programa Operacional Competitividade e Internacionalização (POCI) and by national funds through FCT—Fundação para a Ciência e a Tecnologia; Work at NOVA School of Science and Technology FCT I.P., was funded by national funds from FCT—Fundação para a Ciência e a Tecnologia, I.P., in the scope of the project UIDP/04378/2020 and UIDB/04378/2020 of the Research Unit on Applied Molecular Biosciences—UCIBIO and the project LA/P/0140/2020 of the Associate Laboratory Institute for Health and Bioeconomy-i4HB. Funding Information: Work at ITQB NOVA was financially supported by the European Union?s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie ID: 867437, and projects UIDB/04612/2020 and UIDP/04612/2020 (Molecular, Structural and Cellular Microbiology), funded by FEDER through COMPETE 2020?Programa Operacional Competitividade e Internacionaliza??o (POCI) and by national funds through FCT?Funda??o para a Ci?ncia e a Tecnologia; Work at NOVA School of Science and Technology FCT I.P., was funded by national funds from FCT?Funda??o para a Ci?ncia e a Tecnologia, I.P., in the scope of the project UIDP/04378/2020 and UIDB/04378/2020 of the Research Unit on Applied Molecular Biosciences?UCIBIO and the project LA/P/0140/2020 of the Associate Laboratory Institute for Health and Bioeconomy-i4HB. Publisher Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland.The large production of non-degradable petrol-based plastics has become a major global issue due to its environmental pollution. Biopolymers produced by microorganisms such as polyhy-droxyalkanoates (PHAs) are gaining potential as a sustainable alternative, but the high cost associated with their industrial production has been a limiting factor. Post-transcriptional regulation is a key step to control gene expression in changing environments and has been reported to play a major role in numerous cellular processes. However, limited reports are available concerning the regulation of PHA accumulation in bacteria, and many essential regulatory factors still need to be identified. Here, we review studies where the synthesis of PHA has been reported to be regulated at the post-transcriptional level, and we analyze the RNA-mediated networks involved. Finally, we discuss the forthcoming research on riboregulation, synthetic, and metabolic engineering which could lead to improved strategies for PHAs synthesis in industrial production, thereby reducing the costs currently associated with this procedure.publishersversionpublishe

Efecto de la percepción del IGV en las empresas importadoras de vestidos de fibras sintéticas provenientes de China a través del puerto del Callao en el período 2000 al 2019

El presente trabajo académico está enfocado en desarrollar la problemática situación de realizar el pago por percepción del IGV en las empresas importadoras de vestido de fibra sintética proveniente de China en el puerto marítimo del Callao. El estudio está diseñado para encontrar cual es el efecto que tiene el pago de este tributo en las importaciones definitiva de nuestro producto, y que factores se ven influenciados en ellos, ya que, se pretende realizar la verificación del impacto que tuve antes y después de su creación. Muchas de las importaciones textiles hacia nuestro país, la gran mayoría de ellas, son provenientes del país Asiático China; por esta transacción, se realiza diferentes pagos de tributos, entre estos, se encuentra la percepción del IGV, o pago adelantado de este impuesto, donde, el importador realiza el pago anticipado de un porcentaje por estar gravadas a este tributo interno; este cobro de las ventas que aún no se han realizado, ha provocado que las empresas muestran una serie de problemas relacionados a préstamos continuos que deben realizar ante las entidades financieras, ya que, al realizar estos pagos, no cuentan con liquidez en su empresa. Por ello, la presente investigación está orientada a toda persona o empresa que realice operaciones similares, así como también, a nuestra comunidad estudiantil para que se vean enriquecidos de más conocimiento del tema en cuestión

Pervasive RNA Regulation of Metabolism Enhances the Root Colonization Ability of Nitrogen-Fixing Symbiotic α-Rhizobia

The rhizosphere and rhizoplane are nutrient-rich but selective environments for the root microbiome. Here, we deciphered a posttranscriptional network regulated by the homologous trans-small RNAs (sRNAs) AbcR1 and AbcR2, which rewire the metabolism of the nitrogen-fixing α-rhizobium Sinorhizobium meliloti during preinfection stages of symbiosis with its legume host alfalfa. The LysR-type regulator LsrB, which transduces the cell redox state, is indispensable for AbcR1 expression in actively dividing bacteria, whereas the stress-induced transcription of AbcR2 depends on the alternative σ factor RpoH1. MS2 affinity purification coupled with RNA sequencing unveiled exceptionally large and overlapping AbcR1/2 mRNA interactomes, jointly representing ⁓6% of the S. meliloti protein-coding genes. Most mRNAs encode transport/metabolic proteins whose translation is silenced by base pairing to two distinct anti-Shine Dalgarno motifs that function independently in both sRNAs. A metabolic model-aided analysis of the targetomes predicted changes in AbcR1/2 expression driven by shifts in carbon/nitrogen sources, which were confirmed experimentally. Low AbcR1/2 levels in some defined media anticipated overexpression growth phenotypes linked to the silencing of specific mRNAs. As a proof of principle, we confirmed AbcR1/2-mediated downregulation of the l-amino acid AapQ permease. AbcR1/2 interactomes are well represented in rhizosphere-related S. meliloti transcriptomic signatures. Remarkably, a lack of AbcR1 specifically compromised the ability of S. meliloti to colonize the root rhizoplane. The AbcR1 regulon likely ranks the utilization of available substrates to optimize metabolism, thus conferring on S. meliloti an advantage for efficient rhizosphere/rhizoplane colonization. AbcR1 regulation is predicted to be conserved in related α-rhizobia, which opens unprecedented possibilities for engineering highly competitive biofertilizers

The Sinorhizobium meliloti RNA chaperone Hfq influences central carbon metabolism and the symbiotic interaction with alfalfa

<p>Abstract</p> <p>Background</p> <p>The bacterial Hfq protein is able to interact with diverse RNA molecules, including regulatory small non-coding RNAs (sRNAs), and thus it is recognized as a global post-transcriptional regulator of gene expression. Loss of Hfq has an extensive impact in bacterial physiology which in several animal pathogens influences virulence. <it>Sinorhizobium meliloti </it>is a model soil bacterium known for its ability to establish a beneficial nitrogen-fixing intracellular symbiosis with alfalfa. Despite the predicted general involvement of Hfq in the establishment of successful bacteria-eukaryote interactions, its function in <it>S. meliloti </it>has remained unexplored.</p> <p>Results</p> <p>Two independent <it>S. meliloti </it>mutants, 2011-3.4 and 1021Δ<it>hfq</it>, were obtained by disruption and deletion of the <it>hfq </it>gene in the wild-type strains 2011 and 1021, respectively, both exhibiting similar growth defects as free-living bacteria. Transcriptomic profiling of 1021Δ<it>hfq </it>revealed a general down-regulation of genes of sugar transporters and some enzymes of the central carbon metabolism, whereas transcripts specifying the uptake and metabolism of nitrogen sources (mainly amino acids) were more abundant than in the wild-type strain. Proteomic analysis of the 2011-3.4 mutant independently confirmed these observations. Symbiotic tests showed that lack of Hfq led to a delayed nodulation, severely compromised bacterial competitiveness on alfalfa roots and impaired normal plant growth. Furthermore, a large proportion of nodules (55%-64%) elicited by the 1021Δ<it>hfq </it>mutant were non-fixing, with scarce content in bacteroids and signs of premature senescence of endosymbiotic bacteria. RT-PCR experiments on RNA from bacteria grown under aerobic and microoxic conditions revealed that Hfq contributes to regulation of <it>nifA </it>and <it>fixK1/K2</it>, the genes controlling nitrogen fixation, although the Hfq-mediated regulation of <it>fixK </it>is only aerobiosis dependent. Finally, we found that some of the recently identified <it>S. meliloti </it>sRNAs co-inmunoprecipitate with a FLAG-epitope tagged Hfq protein.</p> <p>Conclusions</p> <p>Our results support that the <it>S. meliloti </it>RNA chaperone Hfq contributes to the control of central metabolic pathways in free-living bacteria and influences rhizospheric competence, survival of the microsymbiont within the nodule cells and nitrogen fixation during the symbiotic interaction with its legume host alfalfa. The identified <it>S. meliloti </it>Hfq-binding sRNAs are predicted to participate in the Hfq regulatory network.</p

A survey of sRNA families in α-proteobacteria

We have performed a computational comparative analysis of six small non-coding RNA (sRNA) families in α-proteobacteria. Members of these families were first identified in the intergenic regions of the nitrogen-fixing endosymbiont S. meliloti by a combined bioinformatics screen followed by experimental verification. Consensus secondary structures inferred from covariance models for each sRNA family evidenced in some cases conserved motifs putatively relevant to the function of trans-encoded base-pairing sRNAs i.e., Hfq-binding signatures and exposed anti Shine-Dalgarno sequences. Two particular family models, namely αr15 and αr35, shared own sub-structural modules with the Rfam model suhB (RF00519) and the uncharacterized sRNA family αr35b, respectively. A third sRNA family, termed αr45, has homology to the cis-acting regulatory element speF (RF00518). However, new experimental data further confirmed that the S. meliloti αr45 representative is an Hfq-binding sRNA processed from or expressed independently of speF, thus refining the Rfam speF model annotation. All the six families have members in phylogenetically related plant-interacting bacteria and animal pathogens of the order of the Rhizobiales, some occurring with high levels of paralogy in individual genomes. In silico and experimental evidences predict differential regulation of paralogous sRNAs in S. meliloti 1021. The distribution patterns of these sRNA families suggest major contributions of vertical inheritance and extensive ancestral duplication events to the evolution of sRNAs in plant-interacting bacteria

Insights into the function and activity mechanism of stress-induced small non-coding RNAs and the endoribonuclease YbeY in the legume symbiont Sinorhizobium meliloti

In the rhizobia-legume symbiosis, the transition from a free-living state in soil to an intracellular residence within the plant host demands a flexible adaption of invading bacteria to external changes, which involves the coordinated expression of complex gene networks. Therefore, sRNAs expressed by the microsymbiont are expected to be essential regulatory elements for the integration of diverse soil and plant signals and the coordination of the appropriate physiological bacterial response. Despite this evidence, the role of riboregulation in this mutualistic endosymbiosis has remained largely unexplored. Recently, the non-coding RNome of the model rhizobia, Sinorhizobium meliloti, has been extensively characterized by diverse post-genomic high-throughput approaches. The challenge now is deciphering the function of the thousands of sRNA molecules of different type expressed by this bacterium. In this work, we deepened into the knowledge of two sRNAs, previously identified in our group in the S. meliloti genome (del Val et al., 2007), and we explored the involvement in riboregulation of the conserved bacterial YbeY protein. The stress-induced AbcR2 sRNA (Torres-Quesada et al., 2013) integrates the regulon of RpoH1 (σH1factor) acting downstream in the post-transcriptional regulation of multiple transporter mRNAs coding for proteins involved in the uptake of amino acids and other nitrogen sources. The salt- induced NfeR1 is widespread in phylogenetically related α-proteobacteria interacting with eukaryotic hosts (del Val et al., 2012; Reinkensmeier and Giegerich, 2015). Its expression profile and associated phenotypes place this sRNA as a novel regulator of a salt stress response influencing both osmoadaptation and the overall symbiotic performance of S. meliloti on alfalfa roots. The S. meliloti endoribonuclease YbeY influence core RNA metabolism, energy-producing pathways and plasmid-encoded symbiotic functions. Profiling of the SmYbeY-dependent genes and RNA ligands envisages a number of Hfq-independent and -dependent substrates for this RNase, e.g. the nitrogen fixation genes. Although the data presented here reveal that Hfq and SmYbeY participate in largely independent RNA networks, we provide evidence that the Hfq-dependent silencing of genes related to nitrogen fixation and amino acid uptake requires SmYbeY.Tesis Univ. Granada. Programa Oficial de Doctorado en: Biología Fundamental y de SistemasBeca predoctoral JAE PREDOC adscrita al proyecto AGL2009-07925 del Ministerio de Ciencia e Innovación, actualmente conocido como Ministerio de Economía, Industria y Competitividad

Post-Transcriptional Control in the Regulation of Polyhydroxyalkanoates Synthesis

The large production of non-degradable petrol-based plastics has become a major global issue due to its environmental pollution. Biopolymers produced by microorganisms such as polyhydroxyalkanoates (PHAs) are gaining potential as a sustainable alternative, but the high cost associated with their industrial production has been a limiting factor. Post-transcriptional regulation is a key step to control gene expression in changing environments and has been reported to play a major role in numerous cellular processes. However, limited reports are available concerning the regulation of PHA accumulation in bacteria, and many essential regulatory factors still need to be identified. Here, we review studies where the synthesis of PHA has been reported to be regulated at the post-transcriptional level, and we analyze the RNA-mediated networks involved. Finally, we discuss the forthcoming research on riboregulation, synthetic, and metabolic engineering which could lead to improved strategies for PHAs synthesis in industrial production, thereby reducing the costs currently associated with this procedure

Diseño de radio enlace SDH a 21x2 Mb/s o STM-1 El Carmen-Quevedo-Manta

OBJETIVO DE ESTE PROYECTO ES QUE EL CARMEN (MANABI) SE INTEGRE A LA RED DE TELECOMUNICACIONES DE PACIFITEL Y CONMUTE CON LA CENTRAL DE TRANSITO REGIONAL DE MANTA QUE MANEJA LA PROVINCIA DE MANABI. SE DETALLA LA SITUACION ACTUAL DE LA RUTA EL CARMEN-QUEVEDO-MANTA, LA PROBLEMATICA QUE PRESENTA LA CONFIGURACION ACTUAL DE LA RED, Y SE PLANTEA UNA SOLUCION QUE SERVIRA PARA ERRADICAR EL PROBLEMA, CON LA INCORPORACION DE DOS NUEVOS ENLACES DIGITALES. SE PRESENTAN TODOS LOS CALCULOS QUE SE REQUIEREN PARA REALIZAR EL RADIOENLACE ENTRE LOS PUNTOS ESCOGIDOS Y SUS RESULTADOS, TALES COMO LINEAS DE VISTA, DIAGRAMAS DE PERFIL, ZONAS DE FRESNEL, PERDIDAS Y GANANCIAS DEL SISTEMA, ENTRE OTROS.SE MUESTRAN LOS EQUIPOS SELECCIONADOS PARA EL DISEÑO. SE DETALLA EL PROCESO DE INSTALACION NECESARIA, SE REFIERE AL MANTENIMIENTO QUE SE DEBE REALIZAR. SE REALIZA EL ESTUDIO DE LOS COSTOS Y BENEFICIOS QUE SE NECESITAN PARA PONER A FUNCIONAR EL PROYECTO

Diseño de radio enlace SDH a 21x2 Mb/s o STM-1 el Carmen-Quevedo-Manta

Objetivo de este proyecto es que el Carmen (Manabí) se integre a la red de telecomunicaciones de Pacifitel y conmute con la central de transito regional de Manta que maneja la Provincia de Manabi. Se detalla la situación actual de la ruta el Carmen-Quevedo-Manta, la problematica que presenta la configuración actual de la red, y se plantea una solución que servirá para erradicar el problema, con la incorporación de dos nuevos enlaces digitales. Se presentan todos los cálculos que se requieren para realizar el radioenlace entre los puntos escogidos y sus resultados, tales como líneas de vista, diagramas de perfil, zonas de fresnel, pérdidas y ganancias del sistema, entre otros. Se muestran los equipos seleccionados para el diseño. Se detalla el proceso de instalación necesaria, se refiere al mantenimiento que se debe realizar. Se realiza el estudio de los costos y beneficios que se necesitan para poner a funcionar el proyecto.GuayaquilIngeniero en Electricidad Especialización Electrónic

Radio enlace sdh de 212 mb/s o stm-1

Se detalla la situación actual de la ruta El Carmen – Quevedo – Manta, la problemática que presenta la configuración actual de la red, y se plantea una solución que servirá para erradicar el problema, con la incorporación de dos nuevos enlaces digitales. Además, se presentan todos los cálculos que se requieren para realizar el radioenlace entre los puntos escogidos y sus resultados, tales como líneas de vista, diagramas de perfil, Zona de Fresnel, pérdidas y ganancias del sistema, entre otros. Se da una breve explicación de los equipos que se han seleccionado para llevar a cabo el diseño y sus principales características, entre ellos multiplexor y radio. Analizaremos los costos y beneficios del proyecto; finalmente, se tiene las conclusiones y recomendaciones en donde expresamos nuestro análisis final basándose en todo el estudio e investigación que fueron necesarios para el desarrollo del presente trabajo