Influence of wine-like conditions on arginine utilization by lactic acid bacteria

Wine can contain trace amounts of ethyl carbamate (EC), a carcinogen formed when ethanol reacts with carbamyl compounds such as citrulline. EC is produced from arginine by lactic acid bacteria (LAB), e.g., Lactobacillus and Pediococcus. Although the amounts of EC in wine are usually negligible, over the last few years there has been a slight butsteady increase, as climate change has increased temperatures and alcohol levels have become proportionately higher, both of which favor EC formation. In this study, resting cells of LAB were used to evaluate the effects of ethanol, glucose, malic acid, and low pH on the ability of non-oenococcal strains of these bacteria to degrade arginine and excrete citrulline. Malic acid was found to clearly inhibit arginine consumption in all strains. The relation between citrulline produced and arginine consumed was clearly higher in the presence of ethanol (10-12 %) and at low pH (3.0), which is consistent with both the decreased amount of ornithine produced from arginine and the reduction in arginine degradation. In L. brevis and L. buchneri strains isolated from wine and beer, respectively, the synthesis of citrulline from arginine was highest

Isolation, selection, and characterization of highly ethanol-tolerant strains of Oenococcus oeni from south Catalonia

Twenty-one strains of Oenococcus oeni were isolated during the malolactic fermentation of wines from south Catalonia. Due to their high ethanol tolerance (14 %, or more), these strains may serve as promising starters. The strains were screened by assays in a wine-like medium and by their co-inoculation in wine, resulting in the selection of well-performing strains, subsequently shown not to produce the main biogenic amines and lacking the genes involved in their synthesis. The genetic diversity of the isolates was studied by multilocus sequence typing (MLST), in which seven housekeeping genes were sequenced. Although the concatenated allelic profi le of some strains was the same, the profi les obtained by random amplifi cation of polymorphic DNA together with the variable number of tandem repeats at several loci showed that none of the strains were identical. A phylogenetic tree was constructed based on MLST with the seven genes and clearly showed two phylogroups, in accordance with previous studies. The best-performing strains occurred in members of both subgroups, suggesting that the grouping of housekeeping genes is not directly related to adaptation and ethanol tolerance. [Int Microbiol 2013; 16(2):113-123]Keywords: Oenococcus oeni; malolactic fermentation; wine production; multilocus sequence typing (MLST);strain selectio

Una experiencia de educación emocional en el campamento urbano de verano de La Granja Escuela: una innovación en el ámbito del ocio educativo.

Son muy pocas las investigaciones sobre la capacidad educativa de las actividades de tiempo libre educativo infantil y juvenil (formación no reglada) que se celebran en periodo de vacaciones de verano. Así mismo tampoco son frecuentes los trabajos científicos sobre los programas de educación emocional en el ámbito del ocio educativo. En este marco, se presenta un estudio que pretende demostrar que el Método de educación emocional de La Granja en el ámbito de la formación no reglada y del ocio educativo, permite mejorar la competencia emocional de los niños y niñas participantes y disminuir los sus niveles de ansiedad. Se trata de la evaluación de un proyecto innovador desarrollado durante el verano de 2017 de manera práctica y vivencial, mediante juegos, dinámicas y actividades con un reto a conseguir, y donde se utilizan recursos como los caballos de doma natural, actividades de aventura en el bosque o animales de granja, para el desarrollo de competencias emocionales. La muestra la forman un total de 91 niños y niñas de edades comprendidas entre 8 y 12 años. Los resultados ponen en evidencia que en un periodo de cinco semanas es posible obtener mejoras considerables

Selection and characterization of autochthonous strains of Oenococcus oeni for vinification in Priorat (Catalonia, Spain)

The use of autochthonous strains of Oenococcus oeni for inducing malolactic fermentation (MLF) in wines is increasing because they are well adapted to the conditions of a specific area. The main aim of this work was to select O. oeni strains from Priorat (Catalonia, Spain) wines that would be able to carry out the MLF while maintaining the characteristics of the wine. Forty-five autochthonous strains were selected based on their degradation of L-malic acid, resistance to low pH and high ethanol, and the absence of biogenic amine genes. The three strains with the best characteristics were inoculated and MLF was carried out successfully with the final wines showing good characteristics. One of the inoculated O. oeni strains would be a good candidate to study as possible starter culture. It shows that autochthonous O. oeni strains, once selected, have the potential to be used as an inoculum for wines.Multi-strain indigenous Yeast and Bacterial starters for ‘Wild-ferment’ Wine productio

La Recerca en Conservació des de la Visió del Conservador-Restaurador II

Seguint la línia de divulgació científica iniciada durant la Setmana de la Ciència 2013, des de la Secció de Conservació-Restauració de la Facultat de Belles Arts (Universitat de Barcelona volem continuar difonent les investigacions que duem a terme. Des d'aquest any, a més, també volem donar cabuda a la recerca que es desenvolupa des dels Treballs Finals del Master Universitari de Direcció de Projectes de Conservació-Restauraració

Transcriptomic and proteomic analysis of Oenococcus oeni adaptation to wine stress conditions

Oenococcus oeni, the main lactic acid bacteria responsible for malolactic fermentation in wine, has to adapt to stressful conditions, such as low pH and high ethanol content. In this study, the changes in the transcriptome and the proteome of O. oeni PSU-1 during the adaptation period before MLF start have been studied. DNA microarrays were used for the transcriptomic analysis and two complementary proteomic techniques, 2-D DIGE and iTRAQ labeling were used to analyze the proteomic response. One of the most influenced functions in PSU-1 due to inoculation into wine-like medium (WLM) was translation, showing the over-expression of certain ribosomal genes and the corresponding proteins. Amino acid metabolism and transport was also altered and several peptidases were up regulated both at gene and protein level. Certain proteins involved in glutamine and glutamate metabolism showed an increased abundance revealing the key role of nitrogen uptake under stressful conditions. A strong transcriptional inhibition of carbohydrate metabolism related genes was observed. On the other hand, the transcriptional up-regulation of malate transport and citrate consumption was indicative of the use of L-malate and citrate associated to stress response and as an alternative energy source to sugar metabolism. Regarding the stress mechanisms, our results support the relevance of the thioredoxin and glutathione systems in the adaptation of O. oeni to wine related stress. Genes and proteins related to cell wall showed also significant changes indicating the relevance of the cell envelop as protective barrier to environmental stress. The differences found between transcriptomic and proteomic data suggested the relevance of post-transcriptional mechanisms and the complexity of the stress response in O. oeni adaptation. Further research should deepen into the metabolisms mostly altered due to wine conditions to elucidate the role of each mechanism in the O. oeni ability to develop MLF.This work was supported by grants AGL2009-07369ALI and AGL2012-34866ALI from the Spanish Ministry of Economy and Competitiveness. MM is grateful to the pre-doctoral fellowship from the Universitat Rovira i Virgili. JB wish to thank to the Spanish Government for his “Ayuda para la Formación Posdoctoral” research contract.Peer Reviewe

The use of Torulaspora delbrueckii to improve malolactic fermentation

Abstract The potential use of Torulaspora delbrueckii as a starter culture for wine alcoholic fermentation has become a subject of interest in oenological research. The use of this non‐Saccharomyces yeast can modulate different wine attributes, such as aromatic substances, organic acids and phenolic compound compositions. Thus, the obtained wines are different from those fermented with Saccharomyces cerevisiae as the sole starter. Nevertheless, information about the possible effects of T. delbrueckii chemical modulation on subsequent malolactic fermentation is still not fully explained. In general, T. delbrueckii is related to a decrease in toxic compounds that negatively affect Oenococcus oeni and an increase in others that are described as stimulating compounds. In this work, we aimed to compile the changes described in studies using T. delbrueckii in wine that can have a potential effect on O. oeni and highlight those works that directly evaluated O. oeni performance in T. delbrueckii fermented wines

RIE : revista de investigación educativa

Incluye título, resumen y palabras clave en español e inglésResumen basado en el de la publicaciónSe presenta la aportación en educación emocional del Método La Granja, aplicado en el casal de verano realizado en la granja escuela de Santa María de Palautordera el verano de 2017. Se trata de una experiencia de educación no formal propuesta para favorecer el aprendizaje desde la emoción y la experimentación. El objetivo es valorar el efecto de la participación de 127 niños y niñas entre 8 y 14 años en términos de mejora de sus competencias emocionales, así como su percepción sobre la utilidad de lo aprendido. Se sigue un paradigma pragmático que combina datos recogidos por distintas vías de aproximación. Se incluye la aplicación del Cuestionario de Desarrollo Emocional (CDE-9-13 y CDE-SEC, del GROP) antes y al final, más un cuestionario de preguntas abiertas como postest. En la competencia emocional global, así como sus cinco dimensiones: conciencia, regulación, autonomía, competencias sociales y competencias de vida y bienestar, las puntuaciones aumentan, después de su participación en el Casal, esas diferencias resultaron significativas en todos los casos excepto en la última dimensión. Según los análisis lexicométrico y del contenido de las preguntas abiertas, hay coincidencias entre ambas observaciones, cuantitativas y el significado otorgado a la experiencia en términos de competencias emocionales. La discusión y conclusiones más relevantes giran en torno a la importancia de la reflexión como potenciador del aprendizaje, la duración e intensidad de las intervenciones y la alineación de todos los recursos empleados que interactúan de forma sinérgica en torno al logro de los objetivos, temas recogidos ampliamente en la literatura científica.ES

Emotional education. La Granja Method: an innovation in educational leisure

En este trabajo se presenta la aportación en educación emocional del Método La Granja, aplicado en el casal de verano realizado en la granja escuela de Santa María de Palautordera el verano de 2017. Se trata de una experiencia de educación no formal propuesta para favorecer el aprendizaje desde la emoción y la experimentación. El objetivo principal es valorar el efecto de la participación de 127 niños y niñas entre 8 y 14 años en términos de mejora de sus competencias emocionales, así como su percepción sobre la utilidad de lo aprendido. Sigue un paradigma pragmático que combina datos recogidos por distintas vías de aproximación. Incluye la aplicación del Cuestionario de Desarrollo Emocional (CDE-9-13 y CDE-SEC, del GROP) antes y al final, más un cuestionario de preguntas abiertas como postest. En la competencia emocional global, así como sus cinco dimensiones: conciencia, regulación, autonomía, competencias sociales y competencias de vida y bienestar, las puntuaciones aumentan, después de su participación en el Casal, esas diferencias resultaron significativas en todos los casos excepto en la última dimensión. Según los análisis lexicométrico y del contenido de las preguntas abiertas, hay coincidencias entre ambas observaciones, cuantitativas y el significado otorgado a la experiencia en términos de competencias emocionales. La discusión y conclusiones más relevantes giran en torno a la importancia de la reflexión como potenciador del aprendizaje, la duración e intensidad de las intervenciones y la alineación de todos los recursos empleados que interactúan de forma sinérgica en torno al logro de los objetivos, temas recogidos ampliamente en la literatura científica.This paper presents an innovative methodology in the emotional education field, La Granja, which was developed during a summer camp celebrated in 2017 in Santa María de Palautordera (Barcelona-Spain). It is a non-formal education experience proposed to promote learning from the emotions and experiences. The main goal is to assess the effect of this method on 127 children, between 8 and 14 years of age, in terms of improving their emotional competencies, as well as their perception of the usefulness of what they have learned. It follows a pragmatic paradigm that combines data collected by different approaches. It includes the application of the Emotional Development Questionnaire (CDE-9-13 and CDE-SEC, of the GROP) before and at the end of the summer camp, plus the ad hoc survey with open questions as post-test. In the global emotional competence, as well as its five dimensions: awareness, emotional regulation, emotional autonomy, social competencies, and life and wellbeing competencies, the scores increase, after their participation in the summer camp. These differences were significant in all cases except in the last dimension. According to the lexicometric analysis and the content of the open questions, there are coincidences between both quantitative observations and the meaning given to the experience in terms of emotional competencies. The most relevant discussion and conclusions are based on the importance of reflection as a learning enhancer, the duration and intensity of the interventions and the alignment of all the resources used that interact synergistically around the achievement of the objectives, topics broadly included in the scientific literature

Citrate metabolism in lactic acid bacteria: is there a beneficial effect for Oenococcus oeni in wine?

International audienceLactic acid bacteria (LAB) are Gram positive bacteria frequently used in the food industry for fermentation, mainly transformation of carbohydrates into lactic acid. In addition, these bacteria also have the capacity to metabolize citrate, an organic acid commonly found in food products. Its fermentation leads to the production of 4-carbon compounds such as diacetyl, resulting in a buttery flavor desired in dairy products. Citrate metabolism is known to have several beneficial effects on LAB physiology. Nevertheless, a controversial effect of citrate has been described on the acid tolerance of the wine bacterium Oenococcus oeni . This observation raises questions about the effect of citrate on the capacity of O. oeni to conduct malolactic fermentation in highly acidic wines. This review aims to summarize the current understanding of citrate metabolism in LAB, with a focus on the wine bacterium O. oeni . Metabolism with the related enzymes is detailed, as are the involved genes organized in cit loci. The known systems of cit locus expression regulation are also described. Finally, the beneficial effects of citrate catabolism on LAB physiology are reported and the negative impact observed in O. oeni is discussed