393 research outputs found

    Plataforma Rural.

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    41 p. Planimetrías (Planos) solo en formato impresoPeriodo: 2007 - 2008. Proceso de diseño: marzo 2007 -Diciembre 2007. Proceso de construcción: Agosto 2007 - Febrero 2008. Fecha de entrega de la obra: 4 de marzo de 2008. Comisión evaluadora: Juan Román, Andrés Maragaño, Daniel Vargas, Juan Pablo Corvalán, Germán Valenzuela. Profesor guía: German Valenzuela. Ubicación: Ruta K-610, Km. 5.1, Villa Cobin, Comuna de Maule, VII Region, Chile. Participantes construcción: Daniel Zamorano, Francisco Alvarez, Alejandra Ramirez y Junta de vecinos Villa Cobin. Financiamiento: lustre Municipalidad de Maule, Constructora Demotron, Constructora Malpo, Constructora Independencia

    NtrC Adds a New Node to the Complex Regulatory Network of Biofilm Formation and vps Expression in Vibrio cholerae.

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    The biofilm growth mode is important in both the intestinal and environmental phases of the Vibrio cholerae life cycle. Regulation of biofilm formation involves several transcriptional regulators and alternative sigma factors. One such factor is the alternative sigma factor RpoN, which positively regulates biofilm formation. RpoN requires bacterial enhancer-binding proteins (bEBPs) to initiate transcription. The V. cholerae genome encodes seven bEBPs (LuxO, VC1522, VC1926 [DctD-1], FlrC, NtrC, VCA0142 [DctD-2], and PgtA) that belong to the NtrC family of response regulators (RRs) of two-component regulatory systems. The contribution of these regulators to biofilm formation is not well understood. In this study, we analyzed biofilm formation and the regulation of vpsL expression by RpoN activators. Mutants lacking NtrC had increased biofilm formation and vpsL expression. NtrC negatively regulates the expression of core regulators of biofilm formation (vpsR, vpsT, and hapR). NtrC from V. cholerae supported growth and activated glnA expression when nitrogen availability was limited. However, the repressive activity of NtrC toward vpsL expression was not affected by the nitrogen sources present. This study unveils the role of NtrC as a regulator of vps expression and biofilm formation in V. choleraeIMPORTANCE Biofilms play an important role in the Vibrio cholerae life cycle, contributing to both environmental survival and transmission to a human host. Identifying key regulators of V. cholerae biofilm formation is necessary to fully understand how this important growth mode is modulated in response to various signals encountered in the environment and the host. In this study, we characterized the role of RRs that function as coactivators of RpoN in regulating biofilm formation and identified new components in the V. cholerae biofilm regulatory circuitry

    Understanding the performance of an AnMBR treating urban wastewater and food waste via model simulation and characterization of the microbial population dynamics

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    [EN] An anaerobic membrane bioreactor (AnMBR) pilot plant treating kitchen food waste (FW) jointly with urban wastewater was run for 536 days. Different operational conditions were tested varying the sludge retention time (SRT), the hydraulic retention time (HRT) and the penetration factor (PF) of food waste disposers. COD removal efficiency exceeded 90% in all tested conditions. The joint treatment resulted in an almost 3-fold increase in methane production (at 70 days of SRT, 24 h HRT and 80% PF) in comparison with the treatment of urban wastewater only. Mathematical model simulations and Illumina technology were used to obtain in-depth information of this outstanding process performance. Both the PF and SRT factors increased influent biodegradability. The experimental results were accurately reproduced via model simulations modifying only the influent biodegradability. The high SRT and the presence of ground FW in the influent resulted in higher hydrolytic activity. Not only did the Archaea population increase 3-fold but Levilinea genera was also significantly raised. Three new genera characterised by anaerobic fermentation of amino acids (Leptolinea, Aminomonas and Aminobacterium) were among the ten most abundant of the total sequences identified during the joint treatment, indicating an improvement in the hydrolysis step of anaerobic degradation. Influent biodegradability remained at high values when FW addition stopped.This research work has been financially supported by the Generalitat Valenciana (PROMETEO/2012/029 PROJECT), which is gratefully acknowledged.Durán Pinzón, F.; Zamorano -López, N.; Barat, R.; Ferrer, J.; Aguado García, D. (2018). Understanding the performance of an AnMBR treating urban wastewater and food waste via model simulation and characterization of the microbial population dynamics. Process Biochemistry. 67:139-146. https://doi.org/10.1016/j.procbio.2018.02.010S1391466

    Thermophilic anaerobic conversion of raw microalgae: Microbial community diversity in high solids retention systems

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    [EN] The potential of microbial communities for efficient anaerobic conversion of raw microalgae was evaluated in this work. A long-term operated thermophilic digester was fed with three different Organic Loading Rates (OLR) (0.2, 0.3 and 0.4¿g·L¿1·d¿1) reaching 32¿41% biodegradability values. The microbial community analysis revealed a remarkable presence of microorganisms that exhibit high hydrolytic capabilities such as Thermotogae (~44.5%), Firmicutes (~17.6%) and Dictyoglomi, Aminicenantes, Atribacteria and Planctomycetes (below ~5.5%) phyla. The suggested metabolic role of these phyla highlights the importance of protein hydrolysis and fermentation when only degrading microalgae. The ecological analysis of the reactor suggests the implication of the novel group EM3 in fermentation and beta-oxidation pathways during microalgae conversion into methane. Scenedesmus spp. substrate and free ammonia concentration strongly shaped thermophilic reactor microbial structure. Partial Least Square Discriminant Analysis (PLS-DA) remarked the resilient role of minor groups related to Thermogutta, Armatimonadetes and Ruminococcaceae against a potential inhibitor like free ammonia. Towards low-cost biogas production from microalgae, this study reveals valuable information about thermophilic microorganisms that can strongly disrupt microalgae and remain in high solids retention anaerobic digesters.This research work has been supported by the Spanish Ministry of Economy and Competitiveness (MINECO, Project CTM2011-28595-C02-02) jointly with the European Regional Development Fund (ERDF), which are gratefully acknowledged. The authors are thankful to Fernando Fdz-Polanco research team (University of Valladolid, Spain) for providing the thermophilic sludge from their pilot plant to inoculate the bioreactor and Llúcia Martínez and Giusseppe D'Aria from FISABIO sequencing service (Valencia, Spain) for their technical support during the Illumina sequencing design.Zamorano-López, N.; Greses-Huerta, S.; Aguado García, D.; Seco Torrecillas, A.; Borrás Falomir, L. (2019). Thermophilic anaerobic conversion of raw microalgae: Microbial community diversity in high solids retention systems. Algal Research. 41:1-9. https://doi.org/10.1016/j.algal.2019.101533S194

    Acclimatised rumen culture for raw microalgae conversion into biogas: Linking microbial community structure and operational parameters in anaerobic membrane bioreactors (AnMBR)

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    [EN] Ruminal fluid was inoculated in an Anaerobic Membrane Reactor (AnMBR) to produce biogas from raw Scenedesmus. This work explores the microbial ecology of the system during stable operation at different solids retention times (SRT). The 16S rRNA amplicon analysis revealed that the acclimatised community was mainly composed of Anaerolineaceae, Spirochaetaceae, Lentimicrobiaceae and Cloacimonetes fermentative and hydrolytic members. During the highest biodegradability achieved in the AnMBR (62%) the dominant microorganisms were Fervidobacterium and Methanosaeta. Different microbial community clusters were observed at different SRT conditions. Interestingly, syntrophic bacteria Gelria and Smithella were enhanced after increasing 2-fold the organic loading rate, suggesting their importance in continuous systems producing biogas from raw microalgae.This research work has been supported by the Spanish Ministry of Economy and Competitiveness (MINECO, Projects CTM2011-28595-C02-01 and CTM2011-28595-C02-02), which is gratefully acknowledged. The Education, Investigation, Culture and sports Council from the Valencian Generality for the Post-Doctoral fellowship of the third co-author is also acknowledged (APOSTD/2016/104). The authors are thankful to Ion Pérez Baena from the Universitat Politècnica de Valencia, Institut de Ciència I Tecnología Animal for gently providing the ruminal fluid use in this work.Zamorano-López, N.; Borrás Falomir, L.; Giménez, JB.; Seco Torrecillas, A.; Aguado García, D. (2019). Acclimatised rumen culture for raw microalgae conversion into biogas: Linking microbial community structure and operational parameters in anaerobic membrane bioreactors (AnMBR). Bioresource Technology. 290:1-9. https://doi.org/10.1016/j.biortech.2019.121787S1929

    A platform for real-time control education with LEGO MINDSTORMS.

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    A set of software development tools for building real-time control systems on a simple robotics platform is described in the paper. The tools are being used in a real-time systems course as a basis for student projects. The development platform is a low-cost PC running GNU/Linux, and the target system is LEGO MINDSTORMS NXT, thus keeping the cost of the laboratory low. Real-time control software is developed using a mixed paradigm. Functional code for control algorithms is automatically generated in C from Simulink models. This code is then integrated into a concurrent, real-time software architecture based on a set of components written in Ada. This approach enables the students to take advantage of the high-level, model-oriented features that Simulink oers for designing control algorithms, and the comprehensive support for concurrency and real-time constructs provided by Ada

    Effect of long residence time and high temperature over anaerobic biodegradation of Scenedesmus microalgae grown in wastewater

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    [EN] Anaerobic digestion of indigenous Scenedesmus spp. microalgae was studied in continuous lab-scale anaerobic reactors at different temperatures (35 degrees C and 55 degrees C), and sludge retention time - SRT (50 and 70 days). Mesophilic digestion was performed in a continuous stirred-tank reactor (CSTR) and in an anaerobic membrane bioreactor (AnMBR). Mesophilic CSTR operated at 50 days SRT only achieved 11.9% of anaerobic biodegradability whereas in the AnMBR at 70 days SRT and 50 days HRT reached 39.5%, which is even higher than the biodegradability achieved in the thermophilic CSTR at 50 days SRT (30.4%). Microbial analysis revealed a high abundance of cellulose-degraders in both reactors, AnMBR (mainly composed of 9.4% Bacteroidetes, 10.1% Chloroflexi, 8.0% Firmicutes and 13.2% Thermotogae) and thermophilic CSTR (dominated by 23.8% Chloroflexi and 12.9% Firmicutes). However, higher microbial diversity was found in the AnMBR compared to the thermophilic CSTR which is related to the SRT. since high SRT promoted low growth-rate microorganisms, increasing the hydrolytic potential of the system. These results present the membrane technology as a promising approach to revalue microalgal biomass, suggesting that microalgae biodegradability and consequently the methane production could be improved operating at higher SRT. (C) 2018 Elsevier Ltd. All rights reserved.This research work has been supported by the Spanish Ministry of Economy and Competitiveness (MINECO, Project CTM2011-28595-C02-01/02) jointly with the European Regional Development Fund (ERDF), which are gratefully acknowledged. The authors are thankful to Fernando Fernandez-Polanco for providing the thermophilic sludge to inoculate the reactor.This research work has been financially supported by the Generalitat Valenciana (PROMETEO/2012/029 PROJECT), which is gratefully acknowledged.Greses-Huerta, S.; Zamorano -López, N.; Borrás Falomir, L.; Ferrer, J.; Seco Torrecillas, A.; Aguado García, D. (2018). Effect of long residence time and high temperature over anaerobic biodegradation of Scenedesmus microalgae grown in wastewater. Journal of Environmental Management. 218:425-434. https://doi.org/10.1016/j.jenvman.2018.04.086S42543421

    Effects of vitamin D3 supplementation in gilthead seabream (Sparus aurata) juveniles fed diets high in plant based feedstuffs

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    Modern aquaculture feeds tend to contain lower levels of fish based ingredients, while increasing the content of plant ingredients. However, this may alter the vitamin profile of the feeds, leading to unbalanced vitamin supply. Requirements for several vitamins have been established for species such as carps and salmonids, but adequate levels for gilthead sea bream are yet unknown.publishedVersio

    Genetic selection for high growth improves the efficiency of gilthead sea bream (Sparus aurata) in using novel diets with insect meal, single-cell protein and a DHA rich-microalgal oil

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    Genetic selection and novel raw materials for aquafeeds are current key tools in the ongoing effort to increase the productivity, efficiency, and sustainability of the aquaculture sector. Selective breeding could also improve the utilization of novel dietary formulations with emergent ingredients. Gilthead sea bream juveniles, either coming from a selective breeding program based on growth traits, or a non-selected population, were nutritionally challenged with two novel dietary formulations that were compared with a Control diet based on 15% FM and 6% FO dietary commercial levels for this species. The novel formulations included an insect meal diet (INS) at 5% of the diet to replace 33.3% of the dietary FM, or a single-cell protein diet (SCP) at 10% of the diet and to replace 66.7% of the dietary FM. Fish oil was also totally replaced in these diets by a blend of poultry oil and Veramaris algal oil. Better growth and feed utilization of the selected genotype compared to non-selected fish was observed, at any of the diets assayed. INS and SCP novel diets reduced general performance of fish by reducing feed intake. However, selected fish fed novel diets showed very similar growth and lower feed conversion ratio compared with non-selected fish fed a control diet. The novel formulations increased n-3 LC-PUFA in fish tissues, particularly DHA, irrespective of the genotype, as a result of the dietary inclusion of the DHA-rich microalgal oil. Neither genetic selection nor the use of novel raw materials affected fillet proximate composition and consequently, sea bream fillet quality in terms of texture and sensorial perception of consumers. Overall, the results reaffirm the positive effects of selective breeding programs in improving sea bream key productive indicators, as well as support the use of novel dietary formulations, using insect meal from H. illucens, single-cell protein from M. capsulatus as partial replacers of FM in diets for gilthead sea bream (33 and 66% of replacement, respectively), and a blend of DHA-rich microalgal and poultry oils as total replacer of FO.This work was supported by the European Union‘s Horizon 2020 research and innovation program under grant agreement no. 818367; AquaIMPACT—Genomic and nutritional innovations for genetically superior farmed fish to improve efficiency in European aquaculture.info:eu-repo/semantics/publishedVersio
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