Disipación de herbicidas en un suelo enmendado con residuos orgánicos: ensayos en campo e impacto en las comunidades microbianas del suelo

Tesis por compendio de publicaciones[ES]El conocimiento del impacto de los pesticidas en las comunidades microbianas del suelo es un tema de gran interés científico en la actualidad considerando la relevancia de la diversidad y actividad microbiana en numerosas reacciones de formación y descomposición de la materia orgánica y, en definitiva, su incidencia en la conservación y mantenimiento del suelo. Este impacto dependerá de los procesos que afectan al comportamiento de los pesticidas en el suelo especialmente su adsorción-desorción, degradación y movilidad, y de los factores que influyen en ellos que regulan su concentración en la solución del suelo y determinarán su biodisponibilidad condicionando su posible incidencia en la actividad y/o funcionamiento de las comunidades microbianas del suelo. De hecho estos procesos pueden verse afectados de forma no prevista, en relación con las normas de uso establecidas para estos compuestos, cuando el contenido en materia orgánica del suelo se modifica por la aplicación al mismo de materia orgánica exógena o residuos orgánicos de diferente origen como enmiendas orgánicas, práctica muy extendida en los últimos años para mejorar la calidad de los suelos con bajo contenido en materia orgánica. Teniendo en cuenta lo anterior, y considerando, que la mayor parte de los estudios realizados para profundizar en el conocimiento de estos procesos se llevan a cabo en laboratorio, el objetivo principal de esta tesis doctoral fue evaluar el efecto de la aplicación de un residuo orgánico (compost vegetal) en suelos de cultivo como enmienda en la disipación, movilidad y persistencia de los herbicidas triasulfuron y prosulfocarb, y la influencia de esta aplicación simultánea en las comunidades microbianas del suelo como indicadores de la conservación y calidad del suelo. Las conclusiones principales del trabajo de tesis han sido: i) La movilidad de los herbicidas por debajo del horizonte superficial del suelo podría acortar la duración del control residual de las malas hierbas a las que van destinados y dar lugar a contaminaciones de las aguas subterráneas. Por otro lado, las cantidades retenidas en el perfil del suelo podrían exceder el umbral de sensibilidad registrado para cultivos susceptibles con el consiguiente daño en cosechas posteriores. ii) Es necesario llevar a cabo estudios por un período de tiempo más largo que permitan establecer la influencia de las nuevas prácticas agrícolas basadas en la aplicación de residuos orgánicos al suelo sobre el comportamiento de los herbicidas y sobre la estructura microbiana. iii) Es necesario evaluar las características de los residuos orgánicos previamente a su aplicación, especialmente su contenido en carbono orgánico total y soluble, así como los cambios estructurales en los agregados del suelo con el fin de mejorar su fertilidad sin aumentar el impacto ambiental cuando su aplicación coincida con la de los herbicidas. iv) La aplicación de compost vegetal como enmienda orgánica podría ser optimizada previamente a su uso para reducir el riesgo de contaminación de aguas subterráneas por lixiviación de herbicidas y minimizar el impacto de los herbicidas sobre la microbiota del suelo

Holistic assessment of the microbiome dynamics in the substrates used for commercial champignon (Agaricus bisporus) cultivation

Microorganisms strongly influence and are required to generate the selective substrate that provides nutrients and support for fungal growth, and ultimately to induce mushroom fructification under controlled environmental conditions. In this work, the fungal and bacterial microbiota living in the different substrates employed in a commercial crop (compost phase I, II and III, flush 1 and 2, and casing material on day 1, 6 and 8 after compost casing and during flush 1 and 2) have been characterized along the different stages of cultivation by metataxonomic analysis (16S rRNA and ITS2), analysis of phospholipid fatty acid content (PLFAs) and RT-qPCR. Additionally, laccase activity and the content of lignin and complex carbohydrates in compost and casing have been quantified. The bacterial diversity in compost and casing increased throughout the crop cycle boosted by the connection of both substrates. As reflected by the PLFAs, the total living bacterial biomass appears to be negatively correlated with the mycelium of the crop. Agaricus bisporus was the dominant fungal species in colonized substrates, displacing the pre-eminent Ascomycota, accompanied by a sustained increase in laccase activity, which is considered to be a major product of protein synthesis during the mycelial growth of champignon. From phase II onwards, the metabolic machinery of the fungal crop degrades lignin and carbohydrates in compost, while these components are hardly degraded in casing, which reflects the minor role of the casing for nourishing the crop. The techniques employed in this study provide a holistic and detailed characterization of the changing microbial composition in commercial champignon substrates. The knowledge generated will contribute to improve compost formulations (selection of base materials) and accelerate compost production, for instance, through biotechnological interventions in the form of tailored biostimulants and to design environmentally sustainable bio-based casing materialsThe project was funded by the H2020 programme under the Marie Sklodowska-Curie grant agreement no. 742966 and also funded by the ADER project grant no. 2016-IDD-00013. [Correction added on 07 August 2020 after first online publication: Figures 3 and 5 have been corrected in this version

Educación para el desarrollo en Castilla y León: cómo vemos el mundo

439 p.Quienes creemos que son necesarios cambios en el sistema económico, político y financiero mundial que permitan avanzar en el desarrollo humano sostenible de los pueblos, superando las injusticias y las brechas de desigualdad en el acceso a los recursos, siempre hemos considerado la educación como una pieza clave para conducir ese cambio, y a la universidad como un agente fundamental que puede y debe desarrollarla. Es difícil reflexionar sobre la “Educación para el Desarrollo” distanciándose de los acontecimientos que durante los últimos meses están ocurriendo en Europa y España. Estamos viendo y viviendo cómo la crisis financiera y económica es utilizada para justificar decisiones políticas que reducen nuestro nivel de bienestar. Es inevitable la comparación con los planes de ajuste estructural (PAE) que desde los años 80 se impusieron al dictado del FMI y el BM a los países empobrecidos como respuesta a la crisis de la Deuda Externa, así como sus nefastas consecuencias sociales y económicas para los pueblos afectado

Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality

Disipación de herbicidas en un suelo enmendado con residuos orgánicos: ensayos en campo e impacto en las comunidades microbianas del suelo

128 páginas. -- Tesis doctoral. Universidad de Salamanca. Instituto de Recursos Naturales y Agrobiología de Salamanca-CSIC. Leída, 13-12-2019. -- Tesis presentada en formato de artículos. Con el fin de respetar los derechos de autor de las distintas publicaciones, no se muestra el contenido completo del apartado de Resultados y discusión.El objetivo principal del trabajo fue evaluar el efecto de la aplicación de un residuo orgánico (compost vegetal) en suelos de cultivo como enmienda en la disipación, movilidad y persistencia de los herbicidas triasulfuron y prosulfocarb, y la influencia de esta aplicación simultánea en las comunidades microbianas del suelo como indicadores de la conservación y calidad del suelo.Peer reviewe

Long-term effects of imidacloprid, thiacloprid, and clothianidin on the growth and development of Eisenia andrei

10 páginas, 2 tablas, 2 figurasRecently, the high toxicity of neonicotinoids to the survival and reproduction of adult earthworms has become apparent in standard 56-day toxicity tests. The persistence of some neonicotinoids and/or their repeated application may lead to long-term exposure, possibly also affecting other parts of the life cycle of earthworms. The present study aimed at providing insight into the sublethal effects of imidacloprid, thiacloprid, and clothianidin on juvenile Eisenia andrei exposed for 16 weeks in Lufa 2.2 soil. Significant effects on growth and maturation were observed for all compounds. Exposure to 0.125 mg imidacloprid/kg dry soil and 0.03125 and 0.0625 mg thiacloprid/kg dry soil significantly affected the growth of the earthworms, while significant maturation effects were observed at 0.03125 mg/kg dry soil for imidacloprid and thiacloprid and 0.25 mg clothianidin/kg dry soil. The 16-week no-observed-effect concentrations (NOECs) found in the present study were lower than previously reported NOECs for effects on earthworm reproduction. Predicted environmental concentrations after a single application exceeded the observed NOECs for effects on earthworm maturation in the case of imidacloprid and thiacloprid and for effects on earthworm growth in the case of thiacloprid and clothianidin. Environ Toxicol Chem 2022;41:1686-1695. © 2022 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.Peer reviewe

Bovine serum albumin capped cadmium sulphide nanoparticles. Synthesis in aqueous solution and interaction with α-GST

Resumen del póster presentado al VIII International Congress on Analytical Nanoscience and Nanotechnology, celebrado en Barcelona (España) del 3 al 5 de julio de 2017.For the last 20 years, there has been an increasing interest in hybrid materials between inorganic nanoparticles and biomolecules. Today it is simple to control and modify the properties of nanostructures in order to achieve their integration with biological systems. The CdS QDs functionalised with BSA in a colloidal aqueous solution, which are stable over a long period, have been synthesised. The conditions of synthesis, at a homogeneous phase and at low temperature, allow the limiting of the concentration of S2- in solution during the synthesis, which significantly restricts the consequent growth of the NPs. This allows the binding with the BSA in the most favourable manner for the molecule. The existence of Cd2+ ions on the surface of the CdS nanoparticle is counteracted by the negative charge domains of the BSA, the result being the formation of small NPs with a low aggregation tendency. The pH (Fig 1) and the temperature variables have a great influence on the fluorescent characteristics of the nanoparticles synthesised. The best results are obtained by working at low temperatures (4ºC) and at pH values between 10 and 11. Under these conditions the kinetic control of the hydrolysis of the thioacetamide precursor (Fig. 2) has allowed the obtaining of nanoparticles which attain high fluorescence sustained over time and a stability of over 3 months. The BSA bound to the CdS QD (CdS-BSA) maintains its biological activity to allow subsequent bioconjugation with other biological entities such as peptides, proteins, enzymes, or antibodies. Their interaction with the α-GST antibody produces a strong quenching of fluorescence that proves the possibilities of its use in biological labeling.Peer reviewe

Recycling organic residues in soils as amendments: Effect on the mobility of two herbicides under different management practices

45 páginas, 4 figuras, 1 tabla, 2 tablas suplementarias, 1 figura suplementaria. -- The definitive version is available at http://www.elsevier.comThe addition of organic residues to soil to increase its organic matter content is considered as a viable option for sustainable food production in soils sensitive to degradation and erosion. However, the recycling of these organic residues in agricultural soils needs to be previously appraised because they can modify the behaviour of pesticides when they are simultaneously applied in agricultural practices. This study evaluated the changes in the mobility and persistence of two herbicides, triasulfuron and prosulfocarb, after two repeated applications in field experimental plots in an unamended soil and one amended with green compost (GC) for seven months. Different factors were studied: i) soil without amendment (S), ii) soil amended with two doses of GC (∼12 t C ha−1, S + GC1 and 40 t C ha−1, S + GC2), and iii) soils unamended and amended with different irrigation conditions: non-irrigated and with additional irrigation (2.8 mm per week). After the first application of herbicides, the results initially indicated no significant effects of soil treatments or irrigation conditions for triasulfuron mobility in agreement with the residual concentrations in the soil profile. The effect of irrigation was noted after one month of herbicide application and the effect of the soil treatment was significant after two months because the persistence of triasulfuron in S + GC2 was maintained until 50% of the applied amount. For prosulfocarb, the influence of soil amendment was significant for the initial persistence of the herbicide in S + GC2, higher than in S or S + GC1, in agreement with its adsorption constants for this soil. However, dissipation or leaching of the herbicide over time was not inhibited in this soil. After the repeated application of herbicides, the influence of the treatment of soils and/or irrigation was significant for the leaching and dissipation of both herbicides. The initial dissipation/degradation or leaching of herbicides was higher than after the first application, although persistence was maintained after five months of application in amended soils for triasulfuron and in unamended and amended soils for prosulfocarb. The results confirm that high doses of GC increased the persistence of both herbicides. This practice may offer the possibility of applying a tailored dose of GC to soil for striking a balance between residual concentrations and the soil agronomic effect.This work was funded by the Regional Government Junta de Castilla y León (project CSI240U14)Peer reviewe

Assessment of 14C - Prosulfocarb dissipation mechanism in soil after amendment and its impact on the microbial community.

44 páginas, 5 figuras y 3 tablas .-- The final version is available at http://www.elsevier.comAdding organic amendments to soil could modify the bioavailability of herbicides and lead to changes in the microbial community’s activity and structure. The objective here was to study the dissipation and total mass balance of 14C-labeled prosulfocarb applied at two rates (4 and 10 mg kg-1) in unamended and green compost (GC)-amended soil. Soil dehydrogenase activity (DHA) and phospholipid fatty acid (PLFA) profile analysis were determined to evaluate the effect of herbicide residues on microbial community´s activity and structure over the dissipation period. The dissipation rate of prosulfocarb decreased after soil amendment due to higher herbicide adsorption by the amended soil. The 50% dissipation time (DT50) increased 1.7 times in the unamended soil when the concentration of prosulfocarb increased 2.5 times. The mass balance results indicate that the sum of water and organic extractable fractions represented the highest amounts up to the dissipation of 50% 14C-prosulfocarb. The 14C-herbicide was then mainly mineralized (up to 11%-31%) or formed non-extractable residues (up to 35%-44%). The amount of 14C-prosulfocarb residues extracted with methanol was slightly higher in amended soils than in unamended ones. 14C-prosulfocarb mineralization was higher in unamended soils than in amended ones. The formation of non-extractable residues was continuous, and increased over time. Soil DHA decreased in the unamended soil and was maintained in the GC-amended soil at the end of the assay. The microbial structure was barely disturbed over the prosulfocarb degradation process, although it was clearly influenced by the application of GC. The results obtained reveal the influence organic amendment has on herbicide bioavailability to decrease its biodegradation and buffer its impact on the soil microbial structure.This work was funded by the Regional Government Junta de Castilla y León (project CSI240U14) and by the Provincial Government of Salamanca. V. Barba thanks “Junta de Castilla y León” for his predoctoral contract. J.M. Marín-Benito and C. García-Delgado thank Ministry of Economy and Competitiveness for their respective “Juan de la Cierva-Incorporación” and “Juan de la Cierva-Formación” postdoctoral contracts (IJCI-2014-19538 and JCFI-2015-23543).Peer reviewe

Influence of different agricultural management practices on soil microbial community over dissipation time of two herbicides

52 páginas, 3 figuras, 3 tablas, 1 tabla suplementaria, 5 figuras suplementarias. -- The definitive version is available at http://www.elsevier.comSoil microbiology could be affected by the presence of pesticide residues during intensive farming, potentially threatening the soil environment. The aim here was to assess the dissipation of the herbicides triasulfuron and prosulfocarb, applied as a combined commercial formulation, and the changes in soil microbial communities (through the profile of phospholipid fatty acids (PLFAs) extracted from the soil) during the dissipation time of the herbicides under field conditions. The dissipation of herbicides and the soil microbial structure were assessed under different agricultural practices, such as the repeated application of herbicides (twice), in unamended and amended soils with two organic amendments derived from green compost (GC1 and GC2) and with non-irrigation and irrigation regimes. The results obtained indicate slower dissipation for triasulfuron than for prosulfocarb. The 50% dissipation time (DT50) decreased under all conditions for the second application of triasulfuron, although not for prosulfocarb. The DT50 values for both herbicides increased in the GC2 amended soil with the highest organic carbon (OC) content. The DT50 values decreased for prosulfocarb with irrigation, but not for triasulfuron, despite its higher water solubility. The herbicides did not have any significant effects on the relative population of Gram-negative and Gram-positive bacteria during the assay, but the relative abundance of Actinobacteria increased in all the soils with herbicides. At the end of the assay (215 days), the negative effects of herbicides on fungi abundance were significant (p < 0.05) for all the treatments. These microbiological changes were detected in non-irrigated and irrigated soils, and were more noticeable after the second application of herbicides. Actinobacteria could be responsible for the modification of herbicide degradation rates, which tend to be faster after the second application. This study makes a useful contribution to the evaluation of the soil environment and microbiological risks due to the long-term repeated application of herbicides under different agricultural management practices.This work was funded by Junta de Castilla y León (project CSI240U14). V.B.V., C.G.D. and J.M.M.B. thank Junta de Castilla y León and MINECO by their predoctoral, Juan de la Cierva-Formación (JCFI-2015-23543) and Juan de la Cierva-Incorporación (IJCI-2014-19538) contracts, respectively.Peer reviewe