Abstract
Hanseniaspora guilliermondii is a well-recognized producer of acetate esters associated with fruity and floral aromas. The molecular mechanisms underneath this production or the ...environmental factors modulating it remain unknown. Herein, we found that, unlike Saccharomyces cerevisiae, H. guilliermondii over-produces acetate esters and higher alcohols at low carbon-to-assimilable nitrogen (C:N) ratios, with the highest titers being obtained in the amino acid-enriched medium YPD. The evidences gathered support a model in which the strict preference of H. guilliermondii for amino acids as nitrogen sources results in a channeling of keto-acids obtained after transamination to higher alcohols and acetate esters. This higher production was accompanied by higher expression of the four HgAATs, genes, recently proposed to encode alcohol acetyl transferases. In silico analyses of these HgAat’s reveal that they harbor conserved AATs motifs, albeit radical substitutions were identified that might result in different kinetic properties. Close homologues of HgAat2, HgAat3, and HgAat4 were only found in members of Hanseniaspora genus and phylogenetic reconstruction shows that these constitute a distinct family of Aat’s. These results advance the exploration of H. guilliermondii as a bio-flavoring agent providing important insights to guide future strategies for strain engineering and media manipulation that can enhance production of aromatic volatiles.
Acetate esters production by the wine yeastHanseniaspora guilliermondi.
Abstract
Hanseanispora species, including H. guilliermondii, are long known to be abundant in wine grape-musts and to play a critical role in vinification by modulating, among other aspects, the wine ...sensory profile. Despite this, the genetics and physiology of Hanseniaspora species remains poorly understood. The first genomic sequence of a H. guilliermondii strain (UTAD222) and the discussion of its potential significance are presented in this work. Metabolic reconstruction revealed that H. guilliermondii is not equipped with a functional gluconeogenesis or glyoxylate cycle, nor does it harbours key enzymes for glycerol or galactose catabolism or for biosynthesis of biotin and thiamine. Also, no fructose-specific transporter could also be predicted from the analysis of H. guilliermondii genome leaving open the mechanisms underlying the fructophilic character of this yeast. Comparative analysis involving H. guilliermondii, H. uvarum, H. opuntiae and S. cerevisiae revealed 14 H. guilliermondii-specific genes (including five viral proteins and one β-glucosidase). Furthermore, 870 proteins were only found within the Hanseniaspora proteomes including several β-glucosidases and decarboxylases required for catabolism of biogenic amines. The release of H. guilliermondii genomic sequence and the comparative genomics/proteomics analyses performed, is expected to accelerate research focused on Hanseniaspora species and to broaden their application in the wine industry and in other bio-industries in which they could be explored as cell factories.
As histórias estão presentes nos espaços escolares da infância e contribuem na construção da criança, de suas sensibilidades e subjetividades. As narrativas digitais, que possibilitam a relação entre ...história e tecnologias digitais, podem contribuir na inserção das Tecnologias Digitais na escola e em propostas em educação sexual. Objetiva-se, neste artigo, refletir sobre esse recurso como possibilidade pedagógica na problematização do gênero e sexualidade com a infância. Para isso, são apresentadas algumas reflexões sobre histórias e narrativas, assim como uma revisão de literatura, resultante de uma metodologia de pesquisa bibliográfica às bases de dados de Educação, sobre o uso das narrativas digitais em contextos educativos e também em educação sexual, sexualidade e gênero. Reflete-se também sobre limites e possibilidades desse recurso nas temáticas em discussão e mostra-se um cenário de aprendizagem que clarifica e objetiva a proposição das narrativas digitais nessas temáticas. Dessa forma, compreende-se a importância da busca por novas propostas pedagógicas de educação sexual com crianças, incluindo contribuições das tecnologias digitais nesse processo. Digital storytelling in childhood sexuality education: possibilities and limitations AbstractThe stories are present in kindergarten and contribute to the construction of the child, his/her sensibilities and subjectivities. The digital narratives that enable relationships between stories and digital technologies, can contribute to the integration of digital technologies in schools and to the rise of new proposals on sex education. We aim to reflect on this feature as a learning possibility to the problematization of gender and sexuality with children. Therefore, we present some reflections about stories and narratives, as well as a literature review, resulting from a bibliographical research methodology to databases of Education, on the use of digital storytelling in educational contexts as well as in sex education, specifically sexuality and gender. We also reflect about the limits and possibilities of storytelling in sex education and present a learning scenario that clarifies and concretizes the proposition of digital storytelling in these themes. We understand the importance of the search for new educational proposals for children’s sex education, including the contributions of digital technologies in the process.Keywords: Sexuality. Storytelling. Computers and education. Récits numériques dans l'éducation sexuelle a l'enfance: possibilités et limites Résumé Les histoires sont présentes à l'école maternelle et contribuent à la construction de l'enfant, ses sensibilités et subjectivités. Les récits numériques qui permettent établir des relations entre les histoires et les technologies numériques, peuvent contribuer à l'intégration des technologies numériques dans l’école et à la création de nouvelles propositions sur l'éducation sexuelle. Nous visons à réfléchir sur cette fonctionnalité comme une possibilité d'apprendre à la problématisation du genre et la sexualité avec les enfants. Par conséquent, nous présentons quelques réflexions sur les histoires et récits, ainsi que d'une revue de la littérature, résultant d'une méthodologie de recherche bibliographique à des bases de données de l'éducation, sur l'utilisation de la narration numérique dans des contextes éducatifs ainsi que dans l'éducation sexuelle, en particulier la sexualité et le genre. Nous réfléchissons aussi sur les limites et les possibilités de la narration dans l'éducation sexuelle et présentons un scénario d'apprentissage qui clarifie et concrétise la proposition de la narration numérique dans ces thèmes. Nous comprenons l'importance de la recherche de nouvelles propositions pédagogiques pour l'éducation sexuelle des enfants, y compris les contributions des technologies numériques dans le processus.Mots-clés: Sexualité. Contes. Ordinateurs et Éducation.
Purpose
The purpose of this paper is to review a number of recent initiatives to promote sustainable aquaculture development through improvements to education and training capacity, and innovations ...in the use of eLearning.
Design/methodology/approach
The authors share their experience in these initiatives and demonstrate how e‐learning has been developed in specific cases to better serve the needs of the aquaculture sector, while addressing the pedagogical issues of distance learning and finding the best use of new internet‐based technologies.
Findings
These examples show how to respond to the needs of adult learners who may have a substantially different learner profile to typical campus students and have a more diverse range of needs and background knowledge. Greater focus is needed on defining, enhancing and accrediting knowledge and skills acquired informally and “on the job”, so as to develop more effective formal education interventions.
Practical implications
Adults engaging with job‐related education are not empty vessels requiring to be filled with the correct mix of knowledge and skills by teachers who know all the answers. They are active learners seeking a supportive and enabling structure involving access to appropriate resources, engagement with fellow learners and more expert practitioners, and appropriate challenges and rewards to maximise effort and achievement.
Originality/value
The paper shows that there is substantial social benefit in promoting an innovative and sustainable aquaculture industry that contributes positively to food security and human health. Continued Professional Development involving eLearning and other innovative approaches can make an important contribution throughout the sector.
Microfluidics devices for co-culturing neurons and oligodendrocytes represent an important in vitro research tool to decipher myelination mechanisms in health and disease and in the identification of ...novel treatments for myelin diseases. In reported devices using primary rodent cells, the spontaneous formation of myelin sheaths has been challenging and random orientation of neurites impede the analysis of myelination. Furthermore, fabrication methods for devices show limitations, highlighting the need for novel in vitro cell-based myelination models. In the present study, we describe a compartmentalized cell culture device targeted for neuron-oligodendrocyte co-culturing and myelination studies. In the device, neurites from primary rat dorsal root ganglion (DRG) neurons were capable of forming aligned dense networks in a specific compartment that was physically isolated from neuronal somas. Co-culture of rat DRG neurons and oligodendrocytes, a well-known model to study myelination in vitro, led to interactions between oligodendrocytes and neurites in the device, and the deposition of myelin segments in an aligned distribution was spontaneously formed. For the fabrication of the device, we present a new method that produces polydimethylsiloxane (PDMS)-based devices possessing an open compartment design. The proposed fabrication method takes advantage of an SU-8 photolithography process and 3D printing for mould fabrication. Both the microscale and macroscale features are replicated from the same mould, allowing devices to be produced with high precision and repeatability. The proposed device is applicable for long-term cell culturing, live-cell imaging, and by enhancing aligned myelin distribution, it is a promising tool for experimental setups that address diverse biological questions in the field of myelin research.
The constant need for improvement and innovation at all industries leads to the development of new technologies. Adhesive bonding is a joining technique in constant growth as, replacing conventional ...methods of fastening such as bolts and rivets, as it offers potential weight and cost savings.The adhesive joint most studied and used in industrial applications is the single lap joint (SLJ), mainly due to its simplicity and efficiency. In typical SLJs, however, one of the problems associated with them is the nonuniform stress distribution (shear and peel), being concentrated at the ends of the overlap. This leads to early joint failure, especially if the adhesive is brittle. One of the main areas of investigation in the field of adhesive bonding is the development of methods for reducing such stress concentrations. In fact, functionally graded adhesive joints have been gaining attention as a technique to even those stress distributions along the joint, due to their potential high degree of customization, offering more solutions for application design. Essentially, this method consists of a modified adhesive with properties that vary gradually along the bondline. allowing an enhanced stress distribution along the overlap region.Therefore, the main goal of this work is to propose a new method to decrease stress concentrations by applying the concept of functionally graded adhesive joints using magnetised cork microparticles. Thereupon, a customized apparatus was designed. With the appropriate application of tailored magnetic fields, using a set of magnets arrays, the magnetised microparticles were strategically placed along the bondline, then creating a particle concentration gradient from the ends of the overlap (higher) to the middle (lower).Numerical models were developed to predict the particle distribution along the joint caused by the application of magnetic fields. Those models were based on the phenomenon of magnetophoresis of cork-magnetite microparticles. A characterisation of the magnetic behaviour of cork and magnetised cork microparticles was also performed. Early experimental tests using glass slides with the particles uniformly distributed within the adhesive selected were performed to validate the simulations.Mechanical tests were executed to determine the properties of the following composite arrangements: neat resin and resin with magnetised cork microparticles (uniform and graded distributions), considering various amounts. Bulk specimens were used to perform tensile tests and glass transition temperature measurements. SLJs were also done to evaluate the influence of the reinforcement inclusions (magnetised cork microparticles). Simultaneously to mechanical testing, SEM analysis was made in regard to the particles themselves and the bulk specimens fracture surfaces.Overall, it is concluded that the magnetised cork particles gradely distributed in the overlap region of the SLJ serve as reinforcement inclusions. This way, the newly developed method was validated, along with the apparatus conceived to produce such joints.
In this work, we disclose the genome sequence and a corresponding manually curated annotation of the non-Saccharomyces yeast Hanseniaspora guilliermondii UTAD222, a strain shown to have interesting ...oenological traits for the production of wines with improved aromatic properties.
Purpose - The purpose of this paper is to review a number of recent initiatives to promote sustainable aquaculture development through improvements to education and training capacity, and innovations ...in the use of eLearning.Design methodology approach - The authors share their experience in these initiatives and demonstrate how e-learning has been developed in specific cases to better serve the needs of the aquaculture sector, while addressing the pedagogical issues of distance learning and finding the best use of new internet-based technologies.Findings - These examples show how to respond to the needs of adult learners who may have a substantially different learner profile to typical campus students and have a more diverse range of needs and background knowledge. Greater focus is needed on defining, enhancing and accrediting knowledge and skills acquired informally and "on the job", so as to develop more effective formal education interventions.Practical implications - Adults engaging with job-related education are not empty vessels requiring to be filled with the correct mix of knowledge and skills by teachers who know all the answers. They are active learners seeking a supportive and enabling structure involving access to appropriate resources, engagement with fellow learners and more expert practitioners, and appropriate challenges and rewards to maximise effort and achievement.Originality value - The paper shows that there is substantial social benefit in promoting an innovative and sustainable aquaculture industry that contributes positively to food security and human health. Continued Professional Development involving eLearning and other innovative approaches can make an important contribution throughout the sector.
During alcoholic fermentation yeasts have to cope with a temporal exposure to a diversity of environmental stresses namely high concentrations of sugar, low pH, increasing concentration of ethanol ...and nutrient limitation, in particular, assimilable nitrogen. Yeast assimilable nitrogen is often limiting in grape juice being one of the main reasons for fermentation inefficiencies encountered in contemporary winemaking, especially those related to slow and incomplete fermentations. Under wine-making conditions, initial low levels of nitrogen act by limiting growth and biomass, resulting in a reduced fermentation rate. For that reason, for the development of improved wine yeasts, the principal targets are mainly linked to fermentation performance and final product quality.In this study, with the availability of a yeast prototrophic deletion collection, we were able to identify genes involved in nutrition-linked fermentation attributes by evaluating yeast mutants growth, as a predictor of fermentative activity, on a nitrogen-limited synthetic grape juice medium (GJM67). The inclusion in our experiment design of an additional control condition, GJM267, where nitrogen was not a growth and fermentation limiting factor, allowed the identification of 973 genes involved in wine fermentation adaptation response (WAR - Wine Adaptation Response genes) and 1303genes associated with yeast cells growth under nitrogen limited fermentations (NLF - Nitrogen Limited Fermentation genes). The identification of such genes will not only be useful in the development of improved and vigorous fermentative strains, but also will figure the starting point of a better understanding of the molecular mechanisms behind the wine fermentation process, particularly under nitrogen-stress conditions. In addition, and considering the major role of nitrogen status in the formation of volatile compounds that contribute to final quality of wine, this study also aspired to unveil target genes involved in the formation of hydrogen sulfide, proposing possible subjacent cellular mechanisms behind its formation.In sum, this integrative study clearly provide important information towards the deeper understanding of the mechanism by which S. cerevisiaecopes with nitrogen limitation during winemaking and contributes with new findings on the relationships between nitrogen availability, yeast cell growth and hydrogen sulfide production. Moreover, the specific target genes herein identified could be included in a yeast selection program and may be useful to the industry in designing better strategies to improve wine quality.
Tras la Revolución industrial, la emisión masiva de gases de efecto invernadero ha convertido al ser humano en un agente de cambio de primer orden, produciendo un cambio climático cuyas consecuencias ...tienen un gran impacto sobre las poblaciones. Así, el incremento del nivel del mar está motivando el desplazamiento de comunidades enteras en las islas del Pacífico, o los cambios en los patrones de las precipitaciones degeneran en sequías o lluvias torrenciales que expulsan a sus poblaciones por la destrucción del hábitat o la degradación de los cultivos. En este contexto de expansión migratoria, se aprobó en 2018 el Pacto Mundial para la Migración Segura, Ordenada y Regular, cuyo articulado incluye los motivos ambientales y climáticos como origen migratorio. Por ello, el presente trabajo analizará el contenido del Pacto en relación con esta nueva tendencia migratoria y evaluará si garantiza la protección integral de los migrantes ambientales y climáticos en su articulado.
PDF
