Papers by Marcela Sangorrin
Análisis por ICP MS de seis marcas de Vacunas contra COVID-19, Sep 1, 2024
Como consecuencia de la elevada toxicidad de los productos inyectables, en fase experimental, den... more Como consecuencia de la elevada toxicidad de los productos inyectables, en fase experimental, denominados “vacunas contra COVID-19”, cuyo uso ha sido impulsado vehementemente mediante una masiva campaña mundial de vacunación iniciada a finales del año 2020, la población global ha desarrollado y sufrido innumerables y variadas afecciones a su salud en grados leves, moderados y graves. El número de muertes y efectos adversos asociados a estos inyectables supera con creces a aquellos producidos por la suma de todas las vacunas anteriores. Al respecto, fue notable el aumento atípico de muertes súbitas y también de muertes provocadas por otras dolencias. Este incremento de trastornos en la salud de la población comenzó a manifestarse en concomitancia con el número de personas inoculadas y de dosis administradas por persona, afectando a la población inoculada en particular. Por lo cual, desde el año 2021 queda en evidencia que el incremento en la cantidad y variedad de patologías está claramente asociado a la aplicación de estos productos experimentales. En base a los 24 elementos químicos no declarados detectados hasta finales del año 2023, mediante el empleo de SEM-EDX y otras metodologías, por diferentes grupos de investigadores independientes, para obtener información más precisa sobre el contenido de los viales de las diferentes marcas de “vacunas contra COVID-19”, y considerando el alcance limitado de cada metodología empleada para tal fin, el objetivo de este estudio fue corroborar estos hallazgos, identificar posibles elementos adicionales a los ya descubiertos y cuantificar la cantidad de todos los elementos encontrados. Para tal fin, se analizaron los contenidos de viales de diferentes lotes de las marcas AstraZeneca/Oxford, CanSino Biologics, Pfizer/BioNTech, Sinopharm, Moderna y Sputnik V. Se identificaron con gran precisión y se cuantificaron por ICP-MS 55 elementos químicos no declarados.
Brazilian Journal of Biology, Feb 1, 2018
Although invasive infections and mortality caused by Candida species are increasing among comprom... more Although invasive infections and mortality caused by Candida species are increasing among compromised patients, resistance to common antifungal agents is also an increasing problem. We analyzed 60 yeasts isolated from patients with invasive candidiasis using a PCR/RFLP strategy based on the internal transcribed spacer (ITS2) region to identify different Candida pathogenic species. PCR analysis was performed from genomic DNA with a primer pair of the ITS2-5.8S rDNA region. PCR-positive samples were characterized by RFLP. Restriction resulted in 23 isolates identified as C. albicans using AlwI, 24 isolates as C. parapsilosis using RsaI, and 13 as C. tropicalis using XmaI. Then, a group of all isolates were evaluated for their susceptibility to a panel of previously described killer yeasts, resulting in 75% being susceptible to at least one killer yeast while the remaining were not inhibited by any strain. C. albicans was the most susceptible group while C. tropicalis had the fewest inhibitions. No species-specific pattern of inhibition was obtained with this panel of killer yeasts. Metschnikowia pulcherrima, Pichia kluyveri and Wickerhamomyces anomalus were the strains that inhibited the most isolates of Candida spp.
DOAJ (DOAJ: Directory of Open Access Journals), Sep 1, 2009
Fil: Sosa, Maria Cristina. Universidad Nacional del Comahue. Facultad de Ciencias Agrarias; Argen... more Fil: Sosa, Maria Cristina. Universidad Nacional del Comahue. Facultad de Ciencias Agrarias; Argentina
PubMed, Oct 17, 2009
Yeasts belonging to the genus Dekkera/Brettanomyces, especially the species Dekkera bruxellensis,... more Yeasts belonging to the genus Dekkera/Brettanomyces, especially the species Dekkera bruxellensis, have long been associated with the production of volatile phenols responsible for off-flavour in wines. According to recent reports, the species Pichia guilliermondii could also produce these compounds at the initial stages of fermentation. Based on the abundance of P. guilliermondii in Patagonian winemaking, we decided to study the relevance of indigenous isolates belonging to this species as wine spoilage yeast. Twenty-three indigenous isolates obtained from grape surfaces and red wine musts were analyzed in their capacity to produce volatile phenols on grape must. The relationship between molecular Random Amplified Polymorphic DNA (RAPD) and physiological (killer biotype) patterns detected in indigenous populations of P. guilliermondii and volatile phenol production was also evaluated. Different production levels of 4-ethylphenol, 4-vinylguaiacol and 4-ethylguaiacol were detected among the isolates; however, the values were always lower than those produced by the D. bruxellensis reference strain in the same conditions. High levels of 4-vinylphenol were detected among P. guilliermondii indigenous isolates. The combined use of RAPD and killer biotype allowed us to identify the isolates producing the highest volatile phenol levels.
Fems Yeast Research, Dec 23, 2016
Phylogenetic data on Saccharomyces uvarum strains, isolated for the first time from Patagonian ap... more Phylogenetic data on Saccharomyces uvarum strains, isolated for the first time from Patagonian apple chicha suggest that these strains might have been introduced in Patagonia during the domestication of apples by Mapuche communities.
International Journal of Food Microbiology, Nov 1, 2007
The diversity and killer behaviour of the yeast biota associated with surfaces of four Patagonian... more The diversity and killer behaviour of the yeast biota associated with surfaces of four Patagonian wineries were analyzed in the present study. These wineries were different in their technological and ecological features. Following liquid enrichment of samples from fermentation vat surfaces yeast isolates were identified by pheno-and genotyping and characterized using killer sensitivity patterns. Out of 92 isolated yeasts, 25% were Saccharomyces cerevisiae; 18% were Kloeckera apiculata and 11% were Pichia anomala; other six species representing a low percentage were also found. A particular biota composed mainly by S. cerevisiae (57%) and P. anomala (37%) was found in the winery located far from the other three wineries. As a whole, the wineries using spontaneous fermentation showed a major percentage of S. cerevisiae and a minor percentage of K. apiculata. The present study showed a pronounced heterogeneity in killer behaviour: killer, 35%, neutral, 25% and sensitive, 40%. In particular, S. cerevisiae isolates showed a higher sensitivity to killer reference yeasts than non-Saccharomyces isolates. On the other hand, most of the non-Saccharomyces yeasts isolated from fermentation vats were resistant to Saccharomyces toxins.
Antonie Van Leeuwenhoek International Journal of General and Molecular Microbiology, Jan 22, 2019
The juicing industry generates large amounts of waste that mostly lack commercial value and, in t... more The juicing industry generates large amounts of waste that mostly lack commercial value and, in the absence of waste treatment policies, produces environmental pollution. Also, microbiological spoilage is a major concern in the wine industry and control tools are limited. Taking these challenges into account, agro-industrial waste coming from ultrafiltrated apple and pear juice were used to grow Saccharomyces eubayanus and to produce its killer toxin (SeKT). A Plackett-Burman screening was performed in order to optimize SeKT production in ultrafiltrated apple and pear juice. The optimized medium was characterized: 75% v/v WUJ, 0.5% m/v KH 2 PO 4 , 0.5% m/v MgSO 4 , 0.5% m/v (NH 4)SO 4 , 0.5% g/L urea, 10% v/v glycerol and 0.1% v/v Triton X-100. SeKT produced in WUJ optimised medium was used to perform killer assays against wine spoilage yeasts and showed antagonistic activity against Brettanomyces bruxellensis, Pichia guilliermondii, Pichia manshurica and Pichia membranifaciens. Different inhibition percentages against spoilage species in a wine environment (49-69%) were detected and preserved for at least 48 h. For the first time, this work reports the ability of S. eubayanus to produce a killer toxin with potential use as a biocontrol tool in winemaking. Producing SeKT using agro-industrial waste as an alternative medium to cultivate S. eubayanus would have industrial, economic and ecological benefits.
Letters in Applied Microbiology, Jun 21, 2010
To investigate whether the presence of Pichia guilliermondii impacts on the production of volatil... more To investigate whether the presence of Pichia guilliermondii impacts on the production of volatile phenols from mixed wine fermentations with Dekkera bruxellensis and Saccharomyces cerevisiae. Four inoculation strategies were performed in small-scale fermentations involving P. guilliermondii, D. bruxellensis and S. cerevisiae using Syrah grape juice supplemented with 100 mg l(-1) of p-coumaric acid. High pressure liquid chromatography was used for the quantification or volatile phenols. Significant high levels of 4-ethylphenol and 4-ethylguaicol (720 and 545 microg l(-1), respectively), as well as the highest levels of 4-vinylphenol (>4500 microg l(-1)), were observed when P. guilliermondii species was inoculated from the beginning of the fermentation. The metabolic interaction occurring between the high vinylphenol producer species P. guilliermondii and D. bruxellensis exhibiting a high vinylphenol reductase activity resulted in an increased production of volatile phenols in wine. Pichia guilliermondii must be considered a very important spoilage yeast in the wine industry capable of producing large amounts of volatile phenols.
Biological Control, Jun 1, 2018
Vishniacozyma victoriae and Pichia membranifaciens were selected in a previous work for their bio... more Vishniacozyma victoriae and Pichia membranifaciens were selected in a previous work for their biocontrol effectiveness against Penicillium expansum and Botrytis cinerea, the causal agents of blue and grey mold of pear fruits. The objective of this study was to determine the effects of different nutrient or additives on the growth of the two antagonist yeasts and of the two fungal pathogens in order to develop a rational selection based on nutritional profiles to be used in biocontrol enhancement of decay in pear fruits. Twentysix different nutrient sources including 18 amino acids, five sugars, three inorganic nitrogen and one iron source were tested in vitro for their effect on the growth of the two yeasts and the two pathogens. Nutrients that promoted the growth of the yeasts and inhibited the growth of pathogens were applied with the antagonist to wounded fruits to evaluate their effect on enhancing biocontrol in cold storage. In general, the effect of each additive was specific to the yeasts and pathogens used in the in situ assays. The combination of the yeast and some additives resulted in a significantly higher activity with respect to the single treatments applied separately, producing synergistic effects. The effect of the exogenous application of CaCl 2 and chitosan together with the antagonist yeasts was also evaluated against the two pathogens. The most effective mixtures were the CaCl 2 with the two antagonist yeasts. Our research demonstrates that manipulating the chemical environment by adding several amino acid and/or Cl 2 Ca results in improved antagonistic activity of Vishniacozyma victoriae and Pichia membranifaciens against two postharvest diseases of pear fruits.
Fems Yeast Research, Aug 4, 2014
Mudai is a traditional fermented beverage, made from the seeds of the Araucaria araucana tree by ... more Mudai is a traditional fermented beverage, made from the seeds of the Araucaria araucana tree by Mapuche communities. The main goal of the present study was to identify and characterize the yeast microbiota responsible of Mudai fermentation as well as from A. araucana seeds and bark from different locations in Northern Patagonia. Only Hanseniaspora uvarum and a commercial bakery strain of Saccharomyces cerevisiae were isolated from Mudai and all Saccharomyces isolates recovered from A. araucana seed and bark samples belonged to the cryotolerant species Saccharomyces eubayanus and Saccharomyces uvarum. These two species were already reported in Nothofagus trees from Patagonia; however, this is the first time that they were isolated from A. araucana, which extends their ecological distribution. The presence of these species in A. araucana seeds and bark samples, led us to postulate a potential role for them as the original yeasts responsible for the elaboration of Mudai before the introduction of commercial S. cerevisiae cultures. The molecular and genetic characterization of the S. uvarum and S. eubayanus isolates and their comparison with European S. uvarum strains and S. eubayanus hybrids (S. bayanus and S. pastorianus), allowed their ecology and evolution us to be examined.
Acta horticulturae, Oct 1, 2011
Canadian Journal of Microbiology, Jul 1, 2009
Pichia guilliermondii can produce volatile phenols in the initial stages of wine fermentation; ho... more Pichia guilliermondii can produce volatile phenols in the initial stages of wine fermentation; however, its response to different wine stress conditions has been poorly studied. In this work, we present an analysis of the response of 23 P. guilliermondii indigenous isolates to physical and chemical wine stress factors and to indigenous wine killer yeasts. Principal coordinates analysis (PCoA), based on data obtained from response patterns, was carried out to evaluate the relationships among the isolates. Major differences among the isolates were detected in media plates containing 8% ethanol and in those containing 280 g/L glucose. PCoA identified 3 clusters of isolates with different stress response patterns, indicating a relationship between the tolerance to these compounds and the origin of the isolates. Pichia guilliermondii isolates were sensitive to the toxins produced by the species Hanseniaspora uvarum , Metschnikowia pulcherrima , Wickerhamomyces anomala (ex Pichia anomala ), and Pichia kluyveri , with a maximum level of sensitivity against W. anomala (91% on average). Those isolates obtained from fermenting must proved to be more resistant to killer yeasts than those obtained from grape surfaces. The combined evaluation of the response to physico-chemical and biological factors presented in this work could be a useful standard protocol for the evaluation of the potential spoilage capacity of yeasts in winemaking.
Revista Argentina De Microbiologia, Oct 1, 2010
A new optimized semiquantitative yeast killer assay is reported for the first time. The killer ac... more A new optimized semiquantitative yeast killer assay is reported for the first time. The killer activity of 36 yeast isolates belonging to three species, namely, Metschnikowia pulcherrima, Wickerhamomyces anomala andTorulaspora delbrueckii, was tested with a view to potentially using these yeasts as biocontrol agents against the wine spoilage species Pichia guilliermondii and Pichia membranifaciens. The effectiveness of the classical streak-based (qualitative method) and the new semiquantitative techniques was compared. The percentage of yeasts showing killer activity was found to be higher by the semiquantitative technique (60%) than by the qualitative method (45%). In all cases, the addition of 1% NaCl into the medium allowed a better observation of the killer phenomenon. Important differences were observed in the killer capacity of different isolates belonging to a same killer species. The broadest spectrum of action was detected in isolates of W. anomala NpCC 1023 and 1025, and M. pulcherrima NpCC 1009 and 1013. We also brought experimental evidence supporting the importance of the adequate selection of the sensitive isolate to be used in killer evaluation. The new semiquantitative method proposed in this work enables to visualize the relationship between the number of yeasts tested and the growth of the inhibition halo (specific productivity). Hence, this experimental approach could become an interesting tool to be taken into account for killer yeast selection protocols.
International Journal of Food Microbiology, Jun 1, 2011
This article appeared in a journal published by Elsevier. The attached copy is furnished to the a... more This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues. Other uses, including reproduction and distribution, or selling or licensing copies, or posting to personal, institutional or third party websites are prohibited. In most cases authors are permitted to post their version of the article (e.g. in Word or Tex form) to their personal website or institutional repository. Authors requiring further information regarding Elsevier's archiving and manuscript policies are
International Journal of Food Microbiology, Jun 1, 2013
Putative mechanisms of action associated with the biocontrol capacity of four yeast strains (Cryp... more Putative mechanisms of action associated with the biocontrol capacity of four yeast strains (Cryptoccocus albidus NPCC 1248, Pichia membranifaciens NPCC 1250, Cryptoccocus victoriae NPCC 1263 and NPCC 1259) against Penicillium expansum and Botrytis cinerea were studied by means of in vitro and in situ assays. C. albidus (YP) , a commercial yeast was also evaluated for comparative purposes. The yeast strains exhibited a variety of different mechanisms including: wound colonization, germination inhibition, biofilm formation, secretion of killer toxins, competition for nutrient and secretion of hydrolytic enzymes (protease, chitinase and glucanase). The relationship between strains (and their associated antagonist mechanisms) and in situ antagonist activity was also evaluated. Results indicate that mechanisms such as production of hydrolytic enzymes, the ability for colonization of wounds, production of killer toxin and inhibition of germination are the most important for biocontrol activity. Our study indicate that multiple modes of action may explain why P. membranifaciens NPCC 1250 and C. victoriae NPCC 1263 provided excellent control of postharvest pears disease.
Social Science Research Network, 2022
Springer eBooks, Oct 8, 2013
ABSTRACT After harvest, many fruits are kept in cold storage in order to prolong their availabili... more ABSTRACT After harvest, many fruits are kept in cold storage in order to prolong their availability and shelf life. Often, this requires the application of a chemical fungicide to prevent postharvest decay from decay fungi. An alternative approach for preventing postharvest fungal decay during storage could be based on the treatment of the commodity with antagonistic yeasts. In this regard, the use of cold-adapted yeasts may offer a distinct advantage. Numerous cold-adapted yeast species have been isolated from artificial cold environments, as well as cold-stored fruits. Since the method employed to isolate potential antagonists has a major impact on the type and properties of the antagonist to be identified, it is important to evaluate the consequences of the methods that are presently being utilized and to appraise whether or not they can be improved. Although the mechanism(s) by which yeast antagonists suppress postharvest diseases can be quite variable, competition for nutrients and space plays a major role in their antagonistic activity. Additionally, production of antibiotics, direct parasitism and the induction of resistance in the harvested commodity are other modes of action that have been documented and suggested to play a role in how yeasts suppress postharvest pathogens in harvested fruits. While a few yeast-based products have been on the market, this field of study is still in its infancy and it is likely that several new 441 products will enter the market in near future. Nonetheless, it is necessary to continue to identify new potential microorganisms and to develop a better understanding of the biology of yeast biocontrol systems by involving yeasts, pathogens and host commodity, in order to increase the potential of postharvest biocontrol as a viable alternative to synthetic postharvest fungicides. While the results of this technology are encouraging, we need to continue to explore the potential use of appropriate yeasts worldwide where management practices, types of fruit and decay pathogens can vary considerably.
The International Journal of Biochemistry & Cell Biology, Dec 1, 2000
Myofibrillar proteins, like all other intracellular proteins, are in a dynamic state of continual... more Myofibrillar proteins, like all other intracellular proteins, are in a dynamic state of continual degradation and resynthesis. The proteolytic system responsible for degrading myofibrillar proteins in skeletal muscle is not well defined. A proteolytic activity associated to myofibrils was found in mouse skeletal muscle, as show electrophoretic patterns, and denominated by us, as protease M. During incubation of whole myofibrils at 37°C, myosin heavy chain, h actinin, actin and troponin T suffered degradation. These effects were inhibited selectively by serine protease inhibitors (soybean trypsin inhibitor, di-isopropyl phosphofluoridate, phenylmethanesulfonyl fluoride). Using myofibrils as protease M source, azocaseinolytic activity was also detected. Endogenous inhibitor and various compounds effects on protease M activity were also quantified by trichloroacetic acid soluble products formation, using radiolabeled myofibrils. An endogenous trypsin inhibitor isolated from the muscle cytoplasmic fraction could inhibit protease M activity on myofibrillar proteins and on azocasein. While K + increased protease M activity, the presence of Ca 2 + did not show any effect. Data presented in this study suggest that reported protease M may be implicated in myofibrillar degradation in vivo and isolated endogenous inhibitor may provide a mechanism to control its action in mouse skeletal muscle.
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Papers by Marcela Sangorrin