In this contribution, nanocatalysts with rather diverse architectures were designed to promote different intimacy degrees between Cu and SiO and consequently tune distinct Cu-SiO interactions. Previously synthesized copper nanoparticles were deposited onto SiO (NPCu/SiO) in contrast to ordinarily prepared supported Cu/SiO. NPCu@SiO and SiO@Cu core-shell nanocatalysts were also synthesized, and they were all bulk and surface characterized by XRD, TGA, TEM/HRTEM, H-TPR, XANES, and XPS.
View Article and Find Full Text PDFRecently, there has been a growing interest in using MOF templating to synthesize heterogeneous catalysts based on metal nanoparticles on carbonaceous supports. Unlike the common approach of direct pyrolysis of at high temperatures, this work proposes a reductive chemical treatment under mild conditions before pyrolysis (resulting in ). The resulting material () underwent comprehensive characterization via state-of-the-art aberration-corrected electron microscopy, N physisorption, X-ray absorption spectroscopy, Raman, X-ray photoelectron spectroscopy, and X-ray diffraction.
View Article and Find Full Text PDFYeasts play a crucial role in transforming apple must into cider. While Saccharomyces cerevisiae (Sc) has been traditionally associated to cider fermentations worldwide, cryotolerant species such as Saccharomyces uvarum (Su) as well as natural S. cerevisiae × S.
View Article and Find Full Text PDFPerry is a beverage obtained by fermentation of pear juice, popular in the North Hemisphere. In Argentina it is an emerging market, particularly in the Patagonian region. The aim of this work is to describe and to evaluate the spoilage yeasts associated to six perry samples showing signs of microbiological contamination from a local craft perry company in North Patagonian region.
View Article and Find Full Text PDFPatagonia (Argentina and Chile) harbors the highest Saccharomyces eubayanus genomic diversity and its widest predominance in natural environments. In this work, S. eubayanus was isolated for the first time from a fermentative environment.
View Article and Find Full Text PDFSummary: Cytoscape.js is an open-source JavaScript-based graph library. Its most common use case is as a visualization software component, so it can be used to render interactive graphs in a web browser.
View Article and Find Full Text PDFLong-term “Blue Carbon” burial in seagrass meadows is complicated by other carbon and alkalinity exchanges that shape net carbon sequestration. We measured a suite of such processes, including denitrification, sulfur, and inorganic carbon cycling, and assessed their impact on air-water CO exchange in a typical seagrass meadow underlain by carbonate sediments. Eddy covariance measurements reveal a consistent source of CO to the atmosphere at an average rate of 610 ± 990 μmol m hour during our study and 700 ± 660 μmol m hour (6.
View Article and Find Full Text PDFDifferent species can find convergent solutions to adapt their genome to the same evolutionary constraints, although functional convergence promoted by chromosomal rearrangements in different species has not previously been found. In this work, we discovered that two domesticated yeast species, Saccharomyces cerevisiae, and Saccharomyces uvarum, acquired chromosomal rearrangements to convergently adapt to the presence of sulfite in fermentation environments. We found two new heterologous chromosomal translocations in fermentative strains of S.
View Article and Find Full Text PDFThe Lewis/Brønsted catalytic properties of the Metal-Organic Framework (MOF) nodes can be tuned by simply controlling the solvent employed in the synthetic procedure. In this work, we demonstrate that Hf-MOF-808 can be prepared from a material with a higher amount of Brønsted acid sites, modulated hydrothermal synthesis, to a material with a higher proportion of unsaturated Hf Lewis acid sites, modulated solvothermal synthesis. The Lewis/Brønsted acid properties of the resultant metallic clusters have been studied by different characterization techniques, including XAS, FTIR and NMR spectroscopies, combined with a DFT study.
View Article and Find Full Text PDFThe production of pome fruits as pears and apples, as well as their derived industries, is of great economic importance in North Patagonia. The elaboration of fermented beverages as cider or perry has evidenced a substantial diversification during the last years, with the evaluation of different fruit varieties, yeast starters and technological changes. In this work, two cryotolerant yeasts belonging to the species Saccharomyces uvarum were evaluated at laboratory and pilot scale in sterile and no-sterile pear must.
View Article and Find Full Text PDFThe dynamic nature of the copper cations acting as active sites for selective catalytic reduction of nitrogen oxides with ammonia is investigated using a combined theoretical and spectroscopic approach. Ab initio molecular dynamics simulations of Cu-CHA catalysts in contact with reactants and intermediates at realistic operating conditions show that only ammonia is able to release Cu and Cu cations from their positions coordinated to the zeolite framework, forming mobile Cu(NH) and Cu(NH) complexes that migrate to the center of the cavity. Herein, we give evidence that such mobilization of copper cations modifies the vibrational fingerprint in the 800-1000 cm region of the IR spectra.
View Article and Find Full Text PDFMicrobiological contamination by spoilage yeasts species are frequent during winemaking, and biological control using antagonistic yeasts is considered a more beneficial alternative to conventional synthetic antimicrobials. Saccharomyces eubayanus killer toxin (SeKT) was produced and purified in a synthetic optimized medium. Purification procedure allowed the identification of SeKT as protein with an apparent molecular mass of 70 kDa and activity at physicochemical conditions suitable for winemaking process.
View Article and Find Full Text PDFMetal-organic framework (MOF)-driven synthesis is considered as a promising alternative for the development of new catalytic materials with well-designed active sites. This synthetic approach is used here to gradually transform a new bimetallic MOF, with Pd and Fe as the metal components, by the in situ generation of aniline under mild conditions. This methodology results in a compositionally homogeneous nanocomposite formed by Fe-doped Pd nanoparticles that, in turn, are supported on iron oxide-doped carbon.
View Article and Find Full Text PDFThe wild, cold-adapted parent of hybrid lager-brewing yeasts, Saccharomyces eubayanus, has a complex and understudied natural history. The exploration of this diversity can be used both to develop new brewing applications and to enlighten our understanding of the dynamics of yeast evolution in the wild. Here, we integrate whole genome sequence and phenotypic data of 200 S.
View Article and Find Full Text PDFStress has been defined as any environmental factor that impairs the growth of a living organism. High concentrations of ethanol, sugars and SO as well as temperature variations occurring during winemaking processes are some recognized stress factors that yeasts must overcome in order to avoid stuck or sluggish fermentations. At least two of these factors -sugar and ethanol concentrations- are strongly influenced by the global warming, which become them a worry for the future years in the winemaking industry.
View Article and Find Full Text PDFSaccharomyces uvarum has been recovered from natural habitats and traditionally fermented beverages (apple chicha) in Patagonia. However, this species has never been obtained from industrially relevant beverages like wine or cider in the same region. In this work, different strains belonging to the cryotolerant species S.
View Article and Find Full Text PDFExpanding the previously known family of -onium (ammonium, phosphonium, and sulfonium) organic structure-directing agents (OSDAs) for the synthesis of zeolite MFI, a new member, the arsonium cation, is used for the first time. The new group of tetraalkylarsonium cations has allowed the synthesis of the zeolite ZSM-5 with several different chemical compositions, opening a route for the synthesis of zeolites with a new series of OSDA. Moreover, the use of As replacing N in the OSDA allows the introduction of probe atoms that facilitate the study of these molecules by powder X-ray diffraction (PXRD), solid-state nuclear magnetic resonance (MAS NMR), and X-ray absorption spectroscopy (XAS).
View Article and Find Full Text PDFLack of the prezygotic barrier in the Saccharomyces genus facilitates the construction of artificial interspecific hybrids among different Saccharomyces species. Hybrids that maintain the interesting features of parental strains have been applied in industry for many beneficial purposes. Two of the most important problems faced by wine makers is nitrogen deficiency in grape must and low-temperature fermentation.
View Article and Find Full Text PDFSubnanometric metal species (single atoms and clusters) have been demonstrated to be unique compared with their nanoparticulate counterparts. However, the poor stabilization of subnanometric metal species towards sintering at high temperature (>500 °C) under oxidative or reductive reaction conditions limits their catalytic application. Zeolites can serve as an ideal support to stabilize subnanometric metal catalysts, but it is challenging to localize subnanometric metal species on specific sites and modulate their reactivity.
View Article and Find Full Text PDFThe need for greener procedures is a fact to reduce residues, to decrease industrial costs, and to accomplish the environmental agreements. In an attempt to address this question, we propose the addition of a natural resource, Brazilian diatomite, to an MFI zeolite traditional synthesis. We have characterized the resulting product with different techniques, such as X-ray diffraction, microscopy, and gas sorption, and, afterwards, we evaluate the greenness of the process by the Green Star method.
View Article and Find Full Text PDFNutrient pollution and thermal stress constitute two of the main drivers of global change in the coastal oceans. While different studies have addressed the physiological effects and ecological consequences of these stressors in corals, the role of acquired modifications in the coral epigenome during acclimatory and adaptive responses remains unknown. The present work aims to address that gap by monitoring two types of epigenetic mechanisms, namely histone modifications and DNA methylation, during a 7-week-long experiment in which staghorn coral fragments ( were exposed to nutrient stress (nitrogen, nitrogen + phosphorus) in the presence of thermal stress.
View Article and Find Full Text PDFThe selection of yeasts with low nitrogen requirement is a current need in winemaking. In this work, we analysed nitrogen requirements of strains belonging to the cryotolerant species S. uvarum, S.
View Article and Find Full Text PDFThe synthesis and reactivity of single metal atoms in a low-valence state bound to just water, rather than to organic ligands or surfaces, is a major experimental challenge. Herein, we show a gram-scale wet synthesis of Pt stabilized in a confined space by a crystallographically well-defined first water sphere, and with a second coordination sphere linked to a metal-organic framework (MOF) through electrostatic and H-bonding interactions. The role of the water cluster is not only isolating and stabilizing the Pt atoms, but also regulating the charge of the metal and the adsorption of reactants.
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