180 research outputs found
Genome sequence of Rhizobium sullae HCNT1 isolated from Hedysarum coronarium nodules and featuring peculiar denitrification phenotypes
The genome sequence of Rhizobium sullae strain HCNT1, isolated from root nodules of the legume Hedysarum coronarium growing in wild stands in Tuscany, Italy, is described here. Unlike other R. sullae strains, this isolate features a truncated denitrification pathway lacking NO/N2O reductase activity and displaying high sensitivity to nitrite under anaerobic conditions
Strain-resolved metagenomics approaches applied to biogas upgrading
Genetic heterogeneity is a common trait in microbial populations, caused by de novo mutations and changes in variant frequencies over time. Microbes can thus differ genetically within the same species and acquire different phenotypes. For instance, performance and stability of anaerobic reactors are linked to the composition of the microbiome involved in the digestion process and to the environmental parameters imposing selective pressure on the metagenome, shaping its evolution. Changes at the strain level have the potential to determine variations in microbial functions, and their characterization could provide new insight into ecological and evolutionary processes driving anaerobic digestion. In this work, single nucleotide variant dynamics were studied in two time-course biogas upgrading experiments, testing alternative carbon sources and the response to exogenous hydrogen addition. A cumulative total of 76,229 and 64,289 high-confidence single nucleotide variants were discerned in the experiments related to carbon substrate availability and hydrogen addition, respectively. By combining complementary bioinformatic approaches, the study reconstructed the precise strain count—two for both hydrogenotrophic archaea—and tracked their abundance over time, while also characterizing tens of genes under strong selection. Results in the dominant archaea revealed the presence of nearly 100 variants within genes encoding enzymes involved in hydrogenotrophic methanogenesis. In the bacterial counterparts, 119 mutations were identified across 23 genes associated with the Wood-Ljungdahl pathway, suggesting a possible impact on the syntrophic acetate-oxidation process. Strain replacement events took place in both experiments, confirming the trends suggested by the variants trajectories and providing a comprehensive understanding of the biogas upgrading microbiome at the strain level. Overall, this resolution level allowed us to reveal fine-scale evolutionary mechanisms, functional dynamics, and strain-level metabolic variation that could contribute to the selection of key species actively involved in the carbon dioxide fixation process
Valorization of sewage sludge for volatile fatty acids production and role of microbiome on acidogenic fermentation
This work explored the production of volatile fatty acids (VFA) through the anaerobic digestion of sewage sludge
(SS). The first experiment took place at batch scale to evaluate the combined effect of using a thermal pre-
treatment (120 \ub0C, 15 min) and different Substrate/Inoculum ratios (S/I) (1, 2, 4 and 6 g VS substrate/g VS
inoculum) on the acidogenic potential of the SS. The results showed that the thermal pre-treatment influenced
positively the degree of acidification of the SS at low S/I ratios, reaching maximum of 45%. Afterwards, a
continuous lab-scale experiment, was set-up to study two ranges of organic loading rates (OLR): 1300\u20131600 mg
COD L 121 d 121 and 2400\u20133500 mg COD L 121 d 121 . The highest degree of acidification (22%) was achieved at the
lowest OLR. Analysis of the microbial community in the reactor revealed that OTUs most abundant present genes
related with amino acids and carbohydrates fermentation being crucial for VFA production
The development and evaluation of exercises for meaningful responses in reading in grade two
Research chapter for this study will be found in Ash, Dorothea: "Development and evaluation of silent reading exercises in grade one"
Thesis (M.A.)--Boston Universit
Genomic comparison of lactobacillus helveticusstrains highlights probiotic potential
Lactobacillus helveticus belongs to the large group of lactic acid bacteria (LAB), which are the major players in the fermentation of a wide range of foods. LAB are also present in the human gut, which has often been exploited as a reservoir of potential novel probiotic strains, but several parameters need to be assessed before establishing their safety and potential use for human consumption. In the present study, six L. helveticus strains isolated from natural whey cultures were analyzed for their phenotype and genotype in exopolysaccharide (EPS) production, low pH and bile salt tolerance, bile salt hydrolase (BSH) activity, and antibiotic resistance profile. In addition, a comparative genomic investigation was performed between the six newly sequenced strains and the 51 publicly available genomes of L. helveticus to define the pangenome structure. The results indicate that the newly sequenced strain UC1267 and the deposited strain DSM 20075 can be considered good candidates for gut-adapted strains due to their ability to survive in the presence of 0.2% glycocholic acid (GCA) and 1% taurocholic and taurodeoxycholic acid (TDCA). Moreover, these strains had the highest bile salt deconjugation activity among the tested L. helveticus strains. Considering the safety profile, none of these strains presented antibiotic resistance phenotypically and/or at the genome level. The pangenome analysis revealed genes specific to the new isolates, such as enzymes related to folate biosynthesis in strains UC1266 and UC1267 and an integrated phage in strain UC1035. Finally, the presence of maltose-degrading enzymes and multiple copies of 6-phospho-beta-glucosidase genes in our strains indicates the capability to metabolize sugars other than lactose, which is related solely to dairy niches
TaWRKY10 transcription factor is a novel Jasmonic Acid signalling regulator involved in immunity against Septoria tritici blotch disease in wheat
Septoria tritici blotch (STB), caused by the fungus Zymoseptoria tritici, is currently the main threat to worldwide wheat production in temperate climates. Understanding the genetic mechanisms that underpin the Z. tritici–wheat interaction will be crucial for generating new control strategies against STB. Plant hormones are essential regulators of growth and immunity. In particular, jasmonic acid (JA) plays a central role in defence against necrotrophic plant pathogens, but its role in mediating immunity against Z. tritici is largely unknown. Here we identify the transcription factor TaWRKY10 that is taxonomically restricted to the grass subfamily Pooideae as a novel regulator of JA responses in wheat. We demonstrate by using virus-induced gene silencing that silencing TaWRKY10 leads to increased resistance against Z. tritici with an earlier onset of necrotic symptoms, but with reduced pathogen sporulation. Wheat plants silenced for TaWRKY10 show an up-regulated JA response. Transcriptional profiling of TaWRKY10 knock-down plants indicates that it is a negative regulator of the JA receptor TaCOI1 gene expression. Our data indicate that TaWRKY10 down-regulates JA responses, contributing to the susceptibility of wheat to Z. tritici. We postulate that manipulating TaWRKY10 may provide a strategy to boost STB resistance in wheat
Asistencia técnica para el fortalecimiento de pequeñas unidades productivas para la habilitación de lugares de elaboración de alimentos y comercialización de los productos en ferias municipales
El proyecto tiene como objetivo que los pequeños productores de alimentos puedan habilitar un lugar de elaboración para sus productos, reciban asesoramiento técnico y el control necesario para asegurar la inocuidad de los alimentos. Además, que los productos elaborados tengan un lugar de comercialización controlado y común a los emprendedores que se encuentren dentro de esta metodología de trabajo. Esto lo lograremos trabajando en la generación de dos ordenanzas comunes a los municipios que integren el grupo de trabajo. La primera tiene como objetivo fijar las condiciones mínimas para habilitar, desde la municipalidad, los sectores de elaboración de estos pequeños productores, y la otra ordenanza tendrá como finalidad la creación de una feria en cada municipio donde puedan comercializar sus productos no sólo en el municipio al que pertenecen sino también en los municipios que adhieran al proyecto.Eje: Territorio y estrategias de intervenciónUniversidad Nacional de La Plat
Metabolomic Alterations Do Not Induce Metabolic Burden in the Industrial Yeast M2n[pBKD2-Pccbgl1]-C1 Engineered by Multiple \u3b4-Integration of a Fungal \u3b2-Glucosidase Gene
In the lignocellulosic yeast development, metabolic burden relates to redirection of resources from regular cellular activities toward the needs created by recombinant protein production. As a result, growth parameters may be greatly affected. Noteworthy, Saccharomyces cerevisiae M2n[pBKD2-Pccbgl1]-C1, previously developed by multiple d-integration of the b-glucosidase BGL3, did not show any detectable metabolic burden. This work aims to test the hypothesis that the metabolic burden and the metabolomic perturbation induced by the d-integration of a yeast strain, could differ significantly. The engineered strain was evaluated in terms of metabolic performances and metabolomic alterations in different conditions typical of the bioethanol industry. Results indicate that the multiple d-integration did not affect the ability of the engineered strain to grow on different carbon sources and to tolerate increasing concentrations of ethanol and inhibitory compounds. Conversely, metabolomic profiles were significantly altered both under growing and stressing conditions, indicating a large extent of metabolic reshuffling involved in the maintenance of the metabolic homeostasis. Considering that four copies of BGL3 gene have been integrated without affecting any parental genes or promoter sequences, deeper studies are needed to unveil the mechanisms implied in these metabolomic changes, thus supporting the optimization of protein production in engineered strains
A first assessment of genetic variability in the longhorn beetle Rosalia alpina (Coleoptera: Cerambycidae) from the Italian Apennines
The Rosalia longicorn (Rosalia alpina) is a strictly protected saproxylic beetle, widely distributed in Central and Southern Europe and mainly associated with ancient beech forests. To improve knowledge about the conservation status of R. alpina in Italy, available molecular markers (microsatellites and mitochondrial cytochrome c oxidase I(COI)) were tested for the first time on Italian populations. The study was performed in four sampling sites distributed in two areas placed in Northern (“Foreste Casentinesi” National Park) and Central Apennines (“Abruzzo, Lazio and Molise” National Park) where populational data about Rosalia longicorn were collected in the framework of the European LIFE MIPP Project. The genetic relationship among Apennine and Central/South-eastern European populations was explored by a comparison with mitochondrial DNA (mtDNA) data from literature. Microsatellite markers were only partially informative when applied to R. alpina Italian individuals, although providing some preliminary indication on an extensive gene flow among populations from the Apennines and local ongoing processes of genetic erosion. Genetic data are consistent with previous ecological data suggesting that the maintenance of variability in this species could be related to both habitat continuity and preservation of large senescent or standing dead trees in forests. Finally, a peculiar origin of the Apennine populations of R. alpina from a putative “Glacial Refugium” in Italy was inferred through COI data. The high genetic distance scored among the analysed populations and those from Central and South-eastern Europe indicates that the R. alpina deme from Apennine Mountains might represent a relevant conservation unit in Europe. Further genetic analyses will allow assessing other possible conservation units of R. alpina and, thus, defining large-scale conservation strategies to protect this endangered longhorn beetle in Europe
Genes involved in TGFβ1-driven epithelial-mesenchymal transition of renal epithelial cells are topologically related in the human interactome map
<p>Abstract</p> <p>Background</p> <p>Understanding how mesenchymal cells arise from epithelial cells could have a strong impact in unveiling mechanisms of epithelial cell plasticity underlying kidney regeneration and repair.</p> <p>In primary human tubular epithelial cells (HUTEC) under different TGFβ1 concentrations we had observed epithelial-to-mesenchymal transition (EMT) but not epithelial-myofibroblast transdifferentiation. We hypothesized that the process triggered by TGFβ1 could be a dedifferentiation event. The purpose of this study is to comprehensively delineate genetic programs associated with TGFβ1-driven EMT in our in vitro model using gene expression profile on large-scale oligonucleotide microarrays.</p> <p>Results</p> <p>In HUTEC under TGFβ1 stimulus, 977 genes were found differentially expressed. Thirty genes were identified whose expression depended directly on TGFβ1 concentration. By mapping the differentially expressed genes in the Human Interactome Map using Cytoscape software, we identified a single scale-free network consisting of 2630 interacting proteins and containing 449 differentially expressed proteins. We identified 27 hub proteins in the interactome with more than 29 edges incident on them and encoded by differentially expressed genes. The Gene Ontology analysis showed an excess of up-regulated proteins involved in biological processes, such as "morphogenesis", "cell fate determination" and "regulation of development", and the most up-regulated genes belonged to these categories. In addition, 267 genes were mapped to the KEGG pathways and 14 pathways with more than nine differentially expressed genes were identified. In our model, Smad signaling was not the TGFβ1 action effector; instead, the engagement of RAS/MAPK signaling pathway seems mainly to regulate genes involved in the cell cycle and proliferation/apoptosis.</p> <p>Conclusion</p> <p>Our present findings support the hypothesis that context-dependent EMT generated in our model by TGFβ1 might be the outcome of a dedifferentiation. In fact: 1) the principal biological categories involved in the process concern morphogenesis and development; 2) the most up-regulated genes belong to these categories; and, finally, 3) some intracellular pathways are involved, whose engagement during kidney development and nephrogenesis is well known. These long-term effects of TGFβ1 in HUTEC involve genes that are highly interconnected, thereby generating a scale-free network that we named the "TGFβ1 interactome", whose hubs represent proteins that may have a crucial role for HUTEC in response to TGFβ1.</p
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