1,720,963 research outputs found
Isolation and identification of lactic acid bacteria from grape must
Get PDFEl objetivo de este trabajo fue el de aislar e identificar bacterias ácido-lácticas (BAL) a partir de uvas de tres variedades(Malbec, Cabernet Franc y Cabernet Sauvignon), provenientes de un viñedo localizado en Mendoza, Argentina. Se aislaroncolonias bacterianas del mosto de Cabernet Sauvignon obtenido luego de estrujar las uvas y posterior cultivo en medio MRS suplementado a pH 5.0. La tipificación se efectuó por la técnica RAPD-PCR con el primer M13 y se observó un patrón similar indicando que las colonias pertenecían a la misma especie. Por lo tanto, una de estas muestras se envió para secuenciación y se identificó mediante el análisis de secuencia del gen 16S rDNA como Lactiplantibacillus plantarum. No se logró aislamiento de BAL del mosto de uvas de las variedades Malbec y Cabernet Franc siguiendo los mismos procedimientos.The aim of this work was to isolate and identify lactic acid bacteria from grapes of three vine varieties (Malbec, Cabernet Franc and Cabernet Sauvignon) from a vineyard located in Mendoza, Argentina. We were able to isolate lactic acid bacteria colonies from Cabernet Sauvignon from the grapes after crushing and cultivation in MRS supplemented medium at pH 5.0. The bacterial colonies were typed using RAPD-PCR with M13 primer and a similar pattern was observed indicating it that colonies belonged to the same species. Therefore, one of these samples was submitted for sequencing and identified by the sequence analysis of the 16S rDNA gen as Lactiplantibacillus plantarum. We were not able to isolate lactic acid bacteria from Malbec and Cabernet Franc from crushed grapes nor during alcoholic fermentation.Fil: Pose, Eugenia. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Microbiología Molecular; ArgentinaFil: Rivas, Gabriel Alejandro. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Microbiología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Delfederico, Lucrecia. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Microbiología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Olguin, Nair Temis. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Microbiología Molecular; Argentina. Universidad de Morón; Argentin
Microbial diversity of the soil, rhizosphere and wine from an emerging wine-producing region of Argentina
Get PDFThe aim of this study was to characterize the microbial communities of Malbec vineyards recently established in a re-emerging wine region of Argentina. We studied the wine microbiota at different fermentation stages and the soil and rhizosphere microbial communities of two vineyards. A next-generation sequencing (NGS) approach was used to identify bacterial and fungal communities. The soil and rhizosphere samples showed a predominance of the phyla Proteobacteria and Actinobacteria. The order Rhizobiales stood out in the soil and rhizosphere of the two vineyards analyzed. Members of this order are recognized for their plant-growth promotion properties. Regarding fungal communities, Ascomycota and Basidiomycota were the most abundant phyla. The high abundance of the genus Ilyonectria in one of the vineyards may have impact on the health of vines. In wine samples, we detected low levels of lactic acid bacteria and the persistence of acetic acid bacteria (AAB) throughout the fermentation process, although there were no discernible effects on the acidity of wine. The results achieved could allow winemakers to improve the vineyard management practices and the fermentation process to favor the growth of microorganisms potentially beneficial for the health of the vines and the wine quality, while maintaining the regional microbial biodiversity.Fil: Rivas, Gabriel Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Microbiología Molecular; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Instituto de Microbiología Básica y Aplicada; ArgentinaFil: Semorile, Liliana Carmen. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Microbiología Molecular; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Instituto de Microbiología Básica y Aplicada; ArgentinaFil: Delfederico, Lucrecia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Microbiología Molecular; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Instituto de Microbiología Básica y Aplicada; Argentin
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Biodiversity Study by Dependent and Independent Culture Techniques of a Winery located in a Re-emerging Winegrowing Region of Argentina
Get PDFArgentina se ubica entre los países “top 10” del planeta en lo referido a industria vitivinícola, siendo el 7º productor mundial de vino, el 8º exportador, y el 9º consumidor. Las regiones vitivinícolas tradicionales han sido extensamente estudiadas mediante técnicas que dependen del cultivo de microorganismos en el laboratorio, y en menor medida por técnicas independientes del mismo. Sin embargo, regiones que han estado relegadas por razones políticas, económicas y sociales, hoy son reconocidas como re-emergentes a nivel productivo, pero se encuentran estudiadas muy pobremente o permanecen sin estudiar. La provincia de Buenos Aires se ubica como una región re-emergente de interés socio-económico y cultural debido a su crecimiento en vitivinicultura durante los últimos 20 años. El objetivo del presente trabajo consistió en estudiar por técnicas dependientes e independientes de cultivo, una muestra de mosto de la vendimia 2018 de una bodega bonaerense, con especial énfasis en la comparación de las bacterias del ácido láctico (BAL) detectadas mediante ambos tipos de estudios. Se lograron obtener 6 cepas de BAL: 4 cepas de Lactiplantibacillus plantarum, 1 cepa de Enterococcus mundtii y 1 cepa de Enterococcus durans. La caracterización inicial de las cepas de Lpb. plantarum mediante el estudio de sus cinéticas de crecimiento y resistencia al etanol, permitió sugerirlas como posibles candidatos para la futura formulación de iniciadores de fermentación maloláctica (FML). Por otra parte, mediante la secuenciación masiva del gen 16S rRNA, se observó que los filos más abundantes fueron Proteobacterias, Actinobacterias y Firmicutes, sin embargo, no se lograron encontrar miembros del orden Lactobacillales, al que pertenecen las BAL. Los resultados del presente trabajo refuerzan la necesidad de realizar análisis integrales que permitan incrementar la sensibilidad de detección de BAL en muestras de mosto y vino de estas regiones vitivinícolas re-emergentes. Estudios como el presente, resultan de gran importancia para nuestro país, ya que pueden contribuir con los productores a identificar y resolver inconvenientes, y aportar con sugerencias para mejorar el proceso fermentativo a fin de obtener vinos de mayor calidad e incrementar su valor agregado.Argentina ranks among the "top 10" countries globally in the wine industry, being the 7th largest wine producer, the 8th exporter, and the 9th consumer. Traditional wine regions have been extensively studied using culture-dependent techniques, and to a lesser extent, by cultureindependent techniques. However, regions that have been marginalized due to political, economic, and social reasons are now recognized as re-emerging in terms of productivity but remain poorly studied or unstudied. The province of Buenos Aires is identified as a re-emerging region of socio-economic and cultural interest due to its growth in viticulture over the last 20 years. The objective of this study was to analyze, using both culture-dependent and cultureindependent techniques, a sample of 2018 vintage grape must from a winery in Buenos Aires, with a particular focus on comparing lactic acid bacteria (LAB) detected through both methods. Six LAB strains were isolated: 4 strains of Lactiplantibacillus plantarum, 1 strain of Enterococcus mundtii, and 1 strain of Enterococcus durans. Initial characterization of Lpb. plantarum strains through the study of their growth kinetics and ethanol resistance suggested them as potential candidates for future malolactic fermentation (MLF) starter formulations. Furthermore, amplicon sequencing analysis using the 16S rRNA gene revealed Proteobacteria, Actinobacteria, and Firmicutes as the most abundant phyla; however, members of the Lactobacillales order, to which LAB belong, were not detected. The results of this study emphasize the need for comprehensive analyses to enhance the detection sensitivity of LAB in grape must and wine samples from these re-emerging wine regions. Studies like this one could be relevant for our country, as they can assist producers in identifying and addressing issues and providing suggestions to improve the fermentation process to achieve higher quality wines and increase their added value.Fil: Rivas, Gabriel Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Microbiología Molecular; ArgentinaFil: Pose, Eugenia. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Microbiología Molecular; ArgentinaFil: Delfederico, Lucrecia. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Microbiología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
An indigenous bacterial consortium from Argentinean traditional dry sausages as a pilot-scale fermentation starter
Get PDFIn this work, a fermentation starter involving autochthonous strains obtained from an artisanal dry sausage from Colonia Caroya (Córdoba, Argentina) was formulated, with the aim of preserving the typicity that characterizes this artisanal meat product. Isolates of lactic acid bacteria (LAB) and coagulase-negative-cocci (CNC) were obtained, identified and typified using 16S rRNA gene sequences and RAPD-PCR reactions. Some technological and safety-related properties were also studied: 1-resistance to low pH and high salt concentration, 2-proteolytic and lipolytic activities, 3-antibiotic resistance against tetracycline, kanamycin, vancomycin and ampicillin, and 4-absence of histidine decarboxylase (hdc) gene. A bacterial consortium of one LAB (Latilactobacillus sakei UNQLs16) and five CNC selected strains with the best features was used to formulate a meat fermentation starter (UNQ-MFS), which was compared with a commercial one (C-MFS), in a pilot-scale sausage production. Certain technological parameters (pH and weight reduction, microbial counts, and final texture profiles) were assessed in both batches to ensure the appropriate development of the process. The strains implantation was followed using RAPD-PCR: L. sakei UNQLs16 showed dominance throughout the process and its implantation was confirmed in the batch inoculated with UNQ-MFS, whereas isolates obtained from the C-MFS were not detected in the batch inoculated with this commercial starter. The fermentative starter design with native strains is not only relevant for the regional producers, but also to expand the knowledge and increase the number and diversity of available strains capable of leading the fermentative processes, contributing to safety and quality of foodstuffs.Fil: Rivas, Gabriel Alejandro. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Microbiología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Francioni, Julian. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Microbiología Molecular; ArgentinaFil: Sánchez, Mariana. Instituto Nacional de Tecnología Industrial; ArgentinaFil: Valdés la Hens, Danay. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Microbiología Molecular; ArgentinaFil: Semorile, Liliana Carmen. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Microbiología Molecular; ArgentinaFil: Delfederico, Lucrecia. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Microbiología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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