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Plasmids are extrachromosomal genetic elements commonly found in bacteria. Plasmids are known to fuel bacterial evolution through horizontal gene transfer (HGT), but recent analyses indicate that they can also promote intragenomic adaptations. However, the role of plasmids as catalysts of bacterial evolution beyond HGT remains poorly explored. In this study, we investigate the impact of a widespread conjugative plasmid, pOXA-48, on the evolution of various multidrug-resistant clinical enterobacteria. Combining experimental and within-patient evolution analyses, we unveil that plasmid pOXA-48 promotes bacterial evolution through the transposition of plasmid-encoded insertion sequence 1 (IS1) elements. Specifically, IS1-mediated gene inactivations expedite the adaptation rate of clinical strains in vitro and foster within-patient adaptation in the gut microbiota. We decipher the mechanism underlying the plasmid-mediated surge in IS1 transposition, revealing a negative feedback loop regulated by the genomic copy number of IS1. Given the overrepresentation of IS elements in bacterial plasmids, our findings propose that plasmid-mediated IS transposition represents a crucial mechanism for swift bacterial adaptation.
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Eisenia andrei is considered in OECD and ISO guidelines to be a suitable replacement for Eisenia fetida in ecotoxicological assays. This suggests that other alternative materials and methods could also be used in standard procedures for toxicity testing. The guidelines also favor using less time-consuming procedures and reducing costs and other limitations to ecotoxicological assessments. In recent years, spent coffee grounds (SCG) have been used to produce vermicompost and biochar and as an additive to organic fertilizers. In addition, the physicochemical characteristics of SCG indicate that the material is a suitable substrate for earthworms, with the organisms performing as well as in natural soil. In the present study, a battery of ecotoxicological tests was established with unwashed and washed SCG and a natural reference soil (LUFA 2.2). The test substrates were spiked with different concentrations of silver nitrate. Survival and reproduction of the earthworm E. andrei were assessed under different conditions, along with substrate basal respiration (SBR) as a proxy for microbial activity. Seedling emergence and the germination index of Lepidium sativum were also determined, following standard guidelines. Exposure to silver nitrate had similar effects on earthworm survival and reproduction, as the estimated effective concentrations (EC10 and EC50) in unwashed SCG and LUFA 2.2 overlapped. A hormetic effect was observed for SBR in LUFA 2.2 spiked with 12.8 mg/kg but not in unwashed SCG. Both SBR and root development were inhibited by similar concentrations of silver nitrate in washed SCG. The findings indicate that unwashed SCG could potentially be used as a substrate in E. andrei toxicity tests and support the eventual inclusion of this material in the standard guidelines.
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Oligoquetos , Contaminantes del Suelo , Animales , Suelo/química , Café , Nitrato de Plata/farmacología , Contaminantes del Suelo/análisis , EcotoxicologíaRESUMEN
An increase in the incidence of inflammatory arthritis after COVID-19 has been reported. Since many diseases exhibit population-specific causal effect sizes, we aimed to evaluate the incidence trends of inflammatory arthritis, including rheumatoid arthritis (RA), after COVID-19 in a large admixed Colombian population. Data analysis for this retrospective, population-based cohort study was carried out using the COOSALUD EPS registry. The following codes were selected for analyses: M059, seropositive RA, M069, unspecified RA, M060 seronegative RA, and other RA-related diagnoses: M064, M139, M068, M058, M130 and M053. The study period was limited to January 01, 2018, through December 31, 2022. Incidence rates (IRs) and incidence rate ratios (IRRs) were assessed. A Cox survival model was built to evaluate the influence of age, gender, and COVID-19 vaccination status on the development of inflammatory arthritis. A bioinformatic analysis was performed to evaluate the homology between SARS-CoV-2 and autoantigen peptides related to RA. The entire population study comprised 3,335,084 individuals. During the pandemic period (2020-2022) the total IIR for seropositive and unspecified RA were 1.60 (95% CI, 1.16-2.22) and 2.93 (95% CI, 2.04-4.19), respectively, and the IIR for overall RA-related diagnosis was 2.01 (95% CI 1.59-2.53). The age groups hazard ratios (HRs) were increased until the age group of 51-60 years (HR: 9.16; 95% CI, 7.24-11.59) and then decreased slightly in the age group 61 years or older (HR: 5.364; 95% CI, 4.24-6.78) compared to those within 18-30 years. Men were less at risk than women to develop inflammatory arthritis (HR: 0.21; 95% CI, 0.18-0.24). The greater time since COVID-19 diagnosis was associated with a lower likelihood of developing inflammatory arthritis (HR: 0.99; 95% CI:0.998-0.999). Vaccination (all types of COVID-19 vaccines included) did not prevent the development of inflammatory arthritis after COVID-19. Low identity was found between the SARS-CoV-2 ORF1ab antigen and the human antigens Poly ADP-ribose polymerase 14 and Protein mono-ADP-ribosyltransferase PARP9 isoform D (39% and 29%, respectively). In conclusion, our study confirms increased incidence of inflammatory arthritis, including RA, after COVID-19, with the greatest increase occurring before the first year post-covid. Women in their fifties were more susceptible. Further research is required to examine the effectiveness of vaccination in preventing post-COVID inflammatory arthritis and the mechanisms implicated in the development of RA after COVID-19.
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Artritis Reumatoide , COVID-19 , Masculino , Femenino , Humanos , Persona de Mediana Edad , Factores de Riesgo , Vacunas contra la COVID-19 , Estudios de Cohortes , Incidencia , Estudios Retrospectivos , Prueba de COVID-19 , Estudios Prospectivos , COVID-19/complicaciones , COVID-19/epidemiología , SARS-CoV-2 , Artritis Reumatoide/complicaciones , Artritis Reumatoide/epidemiología , Artritis Reumatoide/diagnósticoRESUMEN
Resumen El propósito de este trabajo fue desarrollar y validar psicométricamente una escala para medir celos románticos en Facebook y WhatsApp, asimismo se buscó evidencia de que los reactivos no tuvieran un funcionamiento diferencial por sexo mediante análisis de invarianza factorial. Se trabajó con dos grupos de participantes de la Ciudad de México, 300 para un análisis factorial exploratorio y 300 para un análisis factorial confirmatorio y prueba de invarianza. Se encontró una estructura con 24 reactivos, adecuada confiabilidad (α = .96) correcto ajuste [χ2 (246) = 433.99, p <.01; CF1 = .99; RMSEA = .05] e invarianza factorial por sexo, por lo que se concluye que la escala es confiable y válida y permite comparación por sexo sin sesgos de medición.
Abstract The purpose of this work was to develop and psychometrically validate a Scale to measure romantic jealousy on Facebook and WhatsApp, also evidence of non-differential function of the items by sex is presented in the form of a factorial invariance test. Two groups of Participants from Mexico City worked on, 300 for an exploratory factor analysis and 300 for confirmatory factor analysis and invariance testing. A structure was found with 24 items, adequate reliability (α .96) corrects fit [χ2 (246) = 433.99, p <.01; CF1 = .99; RMSEA = .05] and factorial invariance by sex, so it is concluded that the Scale is reliable, valid, and allows sex comparison by sex without bias due to measurement.
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Antimicrobial resistance (AMR) in bacteria is a major public health problem. The main route for AMR acquisition in clinically important bacteria is the horizontal transfer of plasmids carrying resistance genes. AMR plasmids allow bacteria to survive antibiotics, but they also entail physiological alterations in the host cell. Multiple studies over the last few years have indicated that these alterations can translate into a fitness cost when antibiotics are absent. However, due to technical limitations, most of these studies are based on analysing new associations between plasmids and bacteria generated in vitro, and we know very little about the effects of plasmids in their native bacterial hosts. In this study, we used a CRISPR-Cas9-tool to selectively cure plasmids from clinical enterobacteria to overcome this limitation. Using this approach, we were able to study the fitness effects of the carbapenem resistance plasmid pOXA-48 in 35 pOXA-48-carrying isolates recovered from hospitalized patients. Our results revealed that pOXA-48 produces variable effects across the collection of wild-type enterobacterial strains naturally carrying the plasmid, ranging from fitness costs to fitness benefits. Importantly, the plasmid was only associated with a significant fitness reduction in four out of 35 clones, and produced no significant changes in fitness in the great majority of isolates. Our results suggest that plasmids produce neutral fitness effects in most native bacterial hosts, helping to explain the great prevalence of plasmids in natural microbial communities.
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Bacterias , Enterobacteriaceae , Humanos , Enterobacteriaceae/genética , Plásmidos/genética , Bacterias/genética , Antibacterianos/farmacología , beta-Lactamasas/genéticaRESUMEN
Dutch elm disease (DED) is a vascular wilt disease caused by the pathogens Ophiostoma ulmi and Ophiostoma novo-ulmi with multiple ecological phases including pathogenic (xylem), saprotrophic (bark) and vector (beetle flight and beetle feeding wound) phases. Due to the two DED pandemics during the twentieth century the use of elms in landscape and forest restoration has declined significantly. However new initiatives for elm breeding and restoration are now underway in Europe and North America. Here we discuss complexities in the DED 'system' that can lead to unintended consequences during elm breeding and some of the wider options for obtaining durability or 'field resistance' in released material, including (1) the phenotypic plasticity of disease levels in resistant cultivars infected by O. novo-ulmi; (2) shortcomings in test methods when selecting for resistance; (3) the implications of rapid evolutionary changes in current O. novo-ulmi populations for the choice of pathogen inoculum when screening; (4) the possibility of using active resistance to the pathogen in the beetle feeding wound, and low attractiveness of elm cultivars to feeding beetles, in addition to resistance in the xylem; (5) the risk that genes from susceptible and exotic elms be introgressed into resistant cultivars; (6) risks posed by unintentional changes in the host microbiome; and (7) the biosecurity risks posed by resistant elm deployment. In addition, attention needs to be paid to the disease pressures within which resistant elms will be released. In the future, biotechnology may further enhance our understanding of the various resistance processes in elms and our potential to deploy trees with highly durable resistance in elm restoration. Hopefully the different elm resistance processes will prove to be largely under durable, additive, multigenic control. Elm breeding programmes cannot afford to get into the host-pathogen arms races that characterise some agricultural host-pathogen systems.
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OBJECTIVE: This clinical case describes a completely digital workflow using current digital technologies for a full-mouth adhesive rehabilitation with ultra-translucent multilayer zirconia restorations. CLINICAL CONSIDERATIONS: A healthy 60-year-old man with abfractions on all upper and lower molars and severe tooth wear underwent a full-mouth rehabilitation with laminate veneers and partial adhesive restorations. A proper zirconia bonding protocol was realized to provide a durable bond between the ultra-translucent zirconia and the resin cement. Furthermore, the implementation of a digital workflow enables the clinician to have an effective communication during treatment planning and simplify the clinical and laboratory procedures, providing the patient with long-term esthetic treatment and functional results. CONCLUSION: The implementation of a completely digital workflow and the use of ultra-translucent multilayer zirconia for indirect adhesive restorations can be an alternative with simplified and predictable procedures for patients with dental wear and teeth discolorations. CLINICAL SIGNIFICANCE: The digital workflow described is intended to facilitate the planning and execution of a full-mouth adhesive rehabilitation and demonstrates to clinicians a reliable zirconia bonding concept for minimally invasive anterior and posterior restorations.
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Cementos Dentales , Rehabilitación Bucal , Masculino , Humanos , Persona de Mediana Edad , Flujo de Trabajo , CirconioRESUMEN
The discovery of Differentially Methylated (DM) regions is an important research field in biology, as it can help to anticipate the risk of suffering from specific diseases. Nevertheless, the high computational cost of the bioinformatic tools developed for this purpose prevents their application to large-scale datasets. Hence, much faster tools are required to further progress in this research field. In this work we present ParRADMeth, a parallel tool that applies beta-binomial regression for the identification of these DM regions. It is based on the state-of-the-art sequential tool RADMeth, which proved superior biological accuracy compared to counterparts in previous experimental evaluations. ParRADMeth provides the same DM regions as RADMeth but at significantly reduced runtime thanks to exploiting the compute capabilities of common multicore CPU clusters. For example, our tool is up to 189 times faster for real data experiments on a cluster with 16 nodes, each one containing two eight-core processors. The source code of ParRADMeth, as well as a reference manual, are available at https://github.com/UDC-GAC/ParRADMeth.
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Biología Computacional , Programas Informáticos , AlgoritmosRESUMEN
Earthworm diversity and ecology in Pakistan is poorly known, especially in the region of Azad Jammu & Kashmir. An earthworm community survey assisted by genetic barcoding detected an unidentified species which could constitute a new record for Pakistan. Morphological study revealed its identity as Perelia kaznakovi. Additionally, Bayesian phylogenetic inference based on five mitochondrial and nuclear molecular markers was performed. Results provided a phylogenetic placement of the genus Perelia within Lumbricidae for the first time, indicating a close relationship with Eophila. This approach should be implemented to Perelia arnoldiana and further representatives of the genus in order to understand their biogeography, diversity and evolutionary history.
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Oligoquetos , Animales , Filogenia , Oligoquetos/genética , Pakistán , Teorema de BayesRESUMEN
Hormogastrid earthworms are found in the diversity hotspot of the Franco-Iberian domain, together with the better-known family Lumbricidae. Integrative systematics (the combination of morphological, molecular and ecological data) have increased our knowledge of the diversity and evolutionary history of these earthworms, highlighting unresolved taxonomic conflicts. One example of a species group in need of integrative taxonomic revision is the genus Boucheona in France. In this work, we analyzed their diversity using previously published data together with additional data obtained from recently sampled localities. Molecular data including DNA barcodes and additional markers enabled us to reconstruct Bayesian and time-calibrated phylogenies to discuss the evolutionary relationships among the different taxa, and to propose hypotheses regarding their biogeographical history. Based on our results, four species of Boucheona are present in Southern France, including two new taxa. Morphological distinctness and molecular phylogenetics results supported the status of four populations as the newly described Boucheona corbierensis sp. nov., as well as the status of "Hormogaster pretiosa var. nigra" as an independent species, redescribed as Boucheona tenebrae sp. nov. These results provide a new perspective of the importance of the genus Boucheona in southern France, as the possible evolutionary origin of a clade of giant anecic earthworms with unknown (but probably remarkable) impact on ecosystem functioning across their range.
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Oligoquetos , Animales , Oligoquetos/genética , Ecosistema , Teorema de Bayes , Evolución Biológica , Filogenia , FranciaRESUMEN
MOTIVATION: Long non-coding RNA (lncRNA) plays a key role in many biological processes. For instance, lncRNA regulates chromatin using different molecular mechanisms, including direct RNA-DNA hybridization via triplexes, cotranscriptional RNA-RNA interactions, and RNA-DNA binding mediated by protein complexes. While the functional annotation of lncRNA transcripts has been widely studied over the last 20 years, barely a handful of tools have been developed with the specific purpose of detecting and evaluating lncRNA-DNA triple helices. What is worse, some of these tools have nearly grown a decade old, making new triplex-centric pipelines depend on legacy software that cannot thoroughly process all the data made available by next-generation sequencing (NGS) technologies. RESULTS: We present PATO, a modern, fast, and efficient tool for the detection of lncRNA-DNA triplexes that matches NGS processing capabilities. PATO enables the prediction of triple helices at the genome scale and can process in as little as 1 h more than 60 GB of sequence data using a two-socket server. Moreover, PATO's efficiency allows a more exhaustive search of the triplex-forming solution space, and so PATO achieves higher levels of prediction accuracy in far less time than other tools in the state of the art. AVAILABILITY AND IMPLEMENTATION: Source code, user manual, and tests are freely available to download under the MIT License at https://github.com/UDC-GAC/pato.
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ARN Largo no Codificante , ARN Largo no Codificante/genética , ARN Largo no Codificante/metabolismo , ADN/metabolismo , Programas InformáticosRESUMEN
Tracing and manipulating cells in embryos are essential to understand development. Lipophilic dye microinjections, viral transfection and iontophoresis have been key to map the origin of the progenitor cells that form the different organs in the post-implantation mouse embryo. These techniques require advanced manipulation skills and only iontophoresis, a demanding approach of limited efficiency, has been used for single-cell labelling. Here, we perform lineage tracing and local gene ablation using cell-permeant Cre recombinase (TAT-Cre) microinjection. First, we map the fate of undifferentiated progenitors to the different heart chambers. Then, we achieve single-cell recombination by titrating the dose of TAT-Cre, which allows clonal analysis of nascent mesoderm progenitors. Finally, injecting TAT-Cre to Mycnflox/flox embryos in the primitive heart tube revealed that Mycn plays a cell-autonomous role in maintaining cardiomyocyte proliferation. This tool will help researchers identify the cell progenitors and gene networks involved in organ development, helping to understand the origin of congenital defects.
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Integrasas , Células Madre , Ratones , Animales , Microinyecciones , Integrasas/genética , Marcación de GenRESUMEN
Background: Leukemia is a neoplasm with high incidence and mortality rates. Mitotic death has been observed in tumor cells treated with chemotherapeutic agents. Ras family proteins participate in the transduction of signals involved in different processes, such as proliferation, differentiation, survival, and paradoxically, initiation of cell death. Methods: This study investigated the effect of H-Ras expression on human T-cell acute lymphoblastic leukemia MOLT-4 cells. Cells were electroporated with either wild-type (Raswt) or oncogenic mutant in codon 12 exon 1 (Rasmut) versions of H-Ras gene and stained for morphological analysis. Cell viability was assessed using trypan blue staining and cell cycle analysis using flow cytometry. H-Ras gene expression was determined using quantitative real-time reverse transcription polymerase chain reaction. The t, ANOVA, and Scheffe tests were used for statistical analysis. Results: Human T-cell acute lymphoblastic leukemia MOLT-4 cells showed nuclear fragmentation and presence of multiple nuclei and micronuclei after transfection with either wt or mutant H-Ras genes. Cell cycle analysis revealed a statistically significant increase in cells in the S phase when transfected with either wt (83.67%, P<0.0005) or mutated (81.79%, P<0.0001) H-Ras genes. Although similar effects for both versions of H-Ras were found, cells transfected with the mutated version died at 120 h of mitotic catastrophe. Conclusion: Transfection of human T-cell acute lymphoblastic leukemia MOLT-4 cells with either normal or mutated H-Ras genes induced alterations in morphology, arrest in the S phase, and death by mitotic catastrophe.
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Host evolutionary history is a key factor shaping the earthworm cast microbiome, although its effect can be shadowed by the earthworm's diet. To untangle dietary from taxon effects, we raised nine earthworm species on a uniform diet of cow manure and compared cast microbiome across species while controlling for diet. Our results showed that, under controlled laboratory conditions, earthworm microbiomes are species-specific, more diverse than that of the controlled diet, and mainly comprised of native bacteria (i.e. not acquired from the diet). Furthermore, diet has a medium to large convergence effect on microbiome composition since earthworms shared 16%-74% of their bacterial amplicon sequence variants (ASV). The interspecies core microbiome included 10 ASVs, while their intraspecies core microbiomes were larger and varied in ASV richness (24%-48%) and sequence abundance across earthworm species. This specificity in core microbiomes and variable degree of similarity in bacterial composition suggest that phylosymbiosis could determine earthworm microbiome assembly. However, lack of congruence between the earthworm phylogeny and the microbiome dendrogram suggests that a consistent diet fed over several generations may have weakened potential phylosymbiotic effects. Thus, cast microbiome assembly in earthworms seem to be the result of an interplay among host phylogeny and diet.
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Microbioma Gastrointestinal , Microbiota , Oligoquetos , Animales , Bacterias/genética , Microbiota/genética , Oligoquetos/microbiología , Filogenia , ARN Ribosómico 16S/genéticaRESUMEN
Palm oil mill waste has a complex cellulosic structure, is rich in nutrients, and provides a habitat for diverse microbial communities. Current research focuses on how the microbiota and organic components interact during the degradation of this type of waste. Some recent studies have described the microbial communities present in different biodegradation processes of palm oil mill waste, identifying the dominant bacteria/fungi responsible for breaking down the cellulosic components. However, understanding the degradation process's mechanisms is vital to eliminating the need for further pretreatment of lignocellulosic compounds in the waste mixture and facilitating the commercialization of palm oil mill waste treatment technology. Thus, the present work aims to review microbial community dynamics via three biological treatment systems comprehensively: composting, vermicomposting, and dark fermentation, to understand how inspiration from nature can further enhance existing degradation processes. The information presented could be used as an umbrella to current research on biological treatment processes and specific research on the bioaugmentation of indigenous microbial consortia isolated during the biological degradation of palm oil mill waste.
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Compostaje , Bacterias/metabolismo , Biodegradación Ambiental , Residuos Industriales/análisis , Consorcios Microbianos , Aceite de Palma/metabolismoRESUMEN
The first steps of heart development imply drastic changes in cell behavior and differentiation. While analysis of fixed embryos allows studying in detail specific developmental stages in a still snapshot, live imaging captures dynamic morphogenetic events, such as cell migration, shape changes, and differentiation, by imaging the embryo as it develops. This complements fixed analysis and expands the understanding of how organs develop during embryogenesis. Despite its advantages, live imaging is rarely used in mouse models because of its technical challenges. Early mouse embryos are sensitive when cultured ex vivo and require efficient handling. To facilitate a broader use of live imaging in mouse developmental research, this paper presents a detailed protocol for two-photon live microscopy that allows long-term acquisition in mouse embryos. In addition to the protocol, tips are provided on embryo handling and culture optimization. This will help understand key events in early mouse organogenesis, enhancing the understanding of cardiovascular progenitor biology.
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Embrión de Mamíferos , Desarrollo Embrionario , Animales , Embrión de Mamíferos/diagnóstico por imagen , Corazón/diagnóstico por imagen , Ratones , Microscopía/métodos , OrganogénesisRESUMEN
The knowledge of the molecular mechanisms that regulate embryonic myogenesis from early myogenic progenitors to myoblasts, as well as the emergence of adult satellite stem cells (SCs) during development, are key concepts to understanding the genesis and regenerative abilities of the skeletal muscle. Several previous pieces of evidence have revealed that the transcription factor Pitx2 might be a player within the molecular pathways controlling somite-derived muscle progenitors' fate and SC behavior. However, the role exerted by Pitx2 in the progression from myogenic progenitors to myoblasts including SC precursors remains unsolved. Here, we show that Pitx2 inactivation in uncommitted early myogenic precursors diminished cell proliferation and migration leading to muscle hypotrophy and a low number of SCs with decreased myogenic differentiation potential. However, the loss of Pitx2 in committed myogenic precursors gave rise to normal muscles with standard amounts of SCs exhibiting high levels of Pax7 expression. This SC population includes few MYF5+ SC-primed but increased amount of less proliferative miR-106b+cells, and display myogenic differentiation defects failing to undergo proper muscle regeneration. Overall our results demonstrate that Pitx2 is required in uncommitted myogenic progenitors but it is dispensable in committed precursors for proper myogenesis and reveal a role for this transcription factor in the generation of diverse SC subpopulations.
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The treatment of winery wastes by using appropriate management technologies is of utmost need in order to reduce to a minimum their disposal and avoid negative environmental impacts. This is of particular interest for grape marc, the main solid by-product of the winery industry. However, comparative studies on a pilot-scale dealing with the impact of earthworms on marc derived from both red and white grape varieties during vermicomposting are still scarce. The present study sought to evaluate the changes in the biochemical and microbiological properties of red and white raw marc in the presence and the absence of the earthworm species Eisenia andrei. The distilled marc obtained through distillation of the red grape marc was also considered under this scenario. Samples were taken after 14, 28, 42, and 63 days of vermicomposting. On day 14 earthworms led to a pronounced increase in most of the enzymatic activities, but only in those vermireactors fed with raw marc from the red grape variety. Alfa- and beta-glucosidase as well as chitinase and leucine-aminopeptidase activities were between 3 to 5-times higher relative to the control, while alkaline phosphomonoesterase was even up to 14-fold higher with earthworm presence. From day 28 onwards the magnitude of earthworms' effect on the studied enzymes was also dependent on the type of grape marc. Reduced values of basal respiration, ranging between 200 and 350 mg CO2 kg OM h-1 and indicative of stabilized materials were found in the resulting vermicomposts. Moreover, the content of macro- and micronutrients in the end products matched with those considered to have the quality criteria of a good vermicompost. Altogether, these findings reinforce the effectiveness of vermicomposting for the biological stabilization of grape marc with the dual purpose of fertilizer production and environmental protection.
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Oligoquetos , Vitis , Animales , Fertilizantes , SueloRESUMEN
The study of microbial communities or microbiotas in animals and environments is important because of their impact in a broad range of industrial applications, diseases and ecological roles. High throughput sequencing (HTS) is the best strategy to characterize microbial composition and function. Microbial profiles can be obtained either by shotgun sequencing of genomes, or through amplicon sequencing of target genes (e.g., 16S rRNA for bacteria and ITS for fungi). Here, we compared both HTS approaches at assessing taxonomic and functional diversity of bacterial and fungal communities during vermicomposting of white grape marc. We applied specific HTS workflows to the same 12 microcosms, with and without earthworms, sampled at two distinct phases of the vermicomposting process occurring at 21 and 63 days. Metataxonomic profiles were inferred in DADA2, with bacterial metabolic pathways predicted via PICRUSt2. Metagenomic taxonomic profiles were inferred in PathoScope, while bacterial functional profiles were inferred in Humann2. Microbial profiles inferred by metagenomics and metataxonomics showed similarities and differences in composition, structure, and metabolic function at different taxonomic levels. Microbial composition and abundance estimated by both HTS approaches agreed reasonably well at the phylum level, but larger discrepancies were observed at lower taxonomic ranks. Shotgun HTS identified ~1.8 times more bacterial genera than 16S rRNA HTS, while ITS HTS identified two times more fungal genera than shotgun HTS. This is mainly a consequence of the difference in resolution and reference richness between amplicon and genome sequencing approaches and databases, respectively. Our study also revealed great differences and even opposite trends in alpha- and beta-diversity between amplicon and shotgun HTS. Interestingly, amplicon PICRUSt2-imputed functional repertoires overlapped ~50% with shotgun Humann2 profiles. Finally, both approaches indicated that although bacteria and fungi are the main drivers of biochemical decomposition, earthworms also play a key role in plant vermicomposting. In summary, our study highlights the strengths and weaknesses of metagenomics and metataxonomics and provides new insights on the vermicomposting of white grape marc. Since both approaches may target different biological aspects of the communities, combining them will provide a better understanding of the microbiotas under study.
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Earthworms heavily modify the soil microbiome as it passes throughout their guts. However, there are no detailed studies describing changes in the composition, structure and diversity of soil microbiomes during gut transit and once they are released back to the soil as casts. To address this knowledge gap, we used 16S rRNA next-generation sequencing to characterize the microbiomes of soil, gut and casts from the earthworm Aporrectodea caliginosa. We also studied whether these three microbiomes are clearly distinct in composition or can be merged into metacommunities. A large proportion of bacteria was unique to each microbiome-soil (82%), gut (89%) and casts (75%), which indicates that the soil microbiome is greatly modified during gut transit. The three microbiomes also differed in alpha diversity, which peaked during gut transit and decreased in casts. Furthermore, gut transit also modified the structure of the soil microbiome, which clustered away from those of the earthworm gut and cast samples. However, this clustering pattern was not supported by metacommunity analysis, which indicated that soil and gut samples make up one metacommunity and cast samples another. These results have important implications for understanding the dynamics of soil microbial communities and nutrient cycles.