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Lachance, Marc-André, Carlos A. Rosa, William T. Starmer y Jane M. Bowles. "Candida ipomoeae, a new yeast species related to large-spored Metschnikowia species". Canadian Journal of Microbiology 44, n.º 8 (1 de agosto de 1998): 718–22. http://dx.doi.org/10.1139/w98-067.
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Numerous strains of an unusual asexual yeast species were isolated from flowers of morning glory (Ipomoea spp., Convolvulaceae) and associated drosophilids and sap beetles of the genus Conotelus sampled in Hawaii and in Brazil. The nutritional profile of this yeast is similar to those of Metschnikowia hawaiiensis and Metschnikowia continentalis, which share the same habitats. The cells are large, hydrophobic, and tend to remain attached after budding, causing the colonies on agar media to have a convoluted appearance, reminiscent of popcorn. The sequences of the D1/D2 domain of large subunit rDNAs of strains from three different localities confirmed that a single species is involved, and that it is related to large-spored Metschnikowia species. The type strain is UWO(PS)91-672.1 (CBS 8466).Key words: Candida ipomoeae, yeast, new species, rDNA.
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Pawlikowska, Ewelina, Monika Szymańska, Joanna Berłowska y Dorota Kręgiel. "Lysates of Metschnikowia yeast with higher content of hydroxyproline". BioResources 15, n.º 2 (20 de marzo de 2020): 3228–36. http://dx.doi.org/10.15376/biores.15.2.3228-3236.
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The chemical characteristics of lysates obtained from yeasts belonging to Metschnikowia spp. were determined. Cell lysis was induced using saponin from Q. saponaria or 5% NaCl. The process was conducted at 50 °C for 24 for 48 h. The enzymatic profiles of the resulting lysates were analyzed. The mannose and glucose contents were also investigated, as well as the concentrations of proteins, free amino nitrogen (FAN), and free amino acids. The results were compared to the characteristics of lysates from conventional industrial strains of Saccharomyces spp. obtained under analogous conditions. The Metschnikowia lysates showed different chemical profiles and the pool of individual amino acids was generally smaller. However, the content of hydroxyproline HPro was 4 to 5 times higher. The results of this study show that yeast lysates are an attractive supplement for numerous applications.
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Pawlikowska, Ewelina, Monika Szymańska, Joanna Berłowska y Dorota Kręgiel. "Lysates of Metschnikowia yeast with higher content of hydroxyproline". BioResources 15, n.º 2 (20 de marzo de 2020): 3228–36. http://dx.doi.org/10.15376/biores.15.2.3228-3236.
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The chemical characteristics of lysates obtained from yeasts belonging to Metschnikowia spp. were determined. Cell lysis was induced using saponin from Q. saponaria or 5% NaCl. The process was conducted at 50 °C for 24 for 48 h. The enzymatic profiles of the resulting lysates were analyzed. The mannose and glucose contents were also investigated, as well as the concentrations of proteins, free amino nitrogen (FAN), and free amino acids. The results were compared to the characteristics of lysates from conventional industrial strains of Saccharomyces spp. obtained under analogous conditions. The Metschnikowia lysates showed different chemical profiles and the pool of individual amino acids was generally smaller. However, the content of hydroxyproline HPro was 4 to 5 times higher. The results of this study show that yeast lysates are an attractive supplement for numerous applications.
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Mažeika K, Pakštas V, Melvydas V y Jagminas A. "Amino acid-assisted synthesis and characterization of zero-Valente iron nanoparticles for research on the bio-interactions with yeast". GSC Advanced Engineering and Technology 4, n.º 1 (30 de junio de 2022): 001–11. http://dx.doi.org/10.30574/gscaet.2022.4.1.0043.
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The wet synthesis of uniformly sized zero-Valente iron nanoparticles (NPs) for application in nanomedicine and biology is still a challenging because of magnetic interaction, oxidation and corrosion. In this study, various Fe-containing NPs were synthesized using amino acids as their size stabilizing agents to investigate their bio-interactions with Metschnikowia spp. yeast strains. For this, D-glutamic, DL-cysteine, DL-methionine, and taurine amino acids were tested. In this way, NPs in size from several to 40 nm, composed of a-Fe0, a-FeB, Fe2O3 and lepidocrocite, g-FeOOH, were synthesized and characterized using X-ray diffraction and Mössbauer spectroscopy, and HRTEM investigations. The surprising influence of amino acid nature and DL-cysteine concentration on the NP size and composition has been revealed allowing fabrication of quite pure lepidocrocite as well as a-Fe0 NPs containing boron. As-synthesized NPs were cultivated in a YEPD growth media for research on the formation of insoluble red pigment pulcherrimin by several Metschnikowia spp. yeast strains. For comparison, the behavior of M. pulcherrima yeast with metallic iron plate and Fe0 NPs has been visualized.
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Пескова, И. В. "Prospects of using non- in winemaking". Magarach Vinogradstvo i Vinodelie, n.º 2(116) (25 de junio de 2021): 190–200. http://dx.doi.org/10.35547/im.2021.23.2.014.
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Изменение климата приводит к повышению содержания сахара в виноградном сусле, снижению концентрации органических кислот, прекурсоров ароматобразующих веществ и т.д. и, как следствие, к повышение содержания алкоголя, нарушению баланса вкуса и искажению аромата вина и другие проблемы. Технологические подходы, предлагаемые для их решения, хотя и позволяют достичь цели, но часто негативно влияют на качество вина. Перспективной альтернативой является использование микроорганизмов, не относящихся к Saccharomyces , продукты метаболизма которых - глицерин, кислоты, маннопротеины, полисахариды и др. - оказывают влияние на органолептические характеристики вина. Так, использование дрожжей Candida spp., Metschnikowia spp., Lachancea spp. способствует снижению содержания этанола в винах на 1,5-2,0% об. Hansensiaspora spp., Pichia spp., Starmerella spp., Torulaspora spp. и др. отличаются высокой способностью к синтезу глицерина и полисахаридов. Использования консорциума дрожжей Saccharomyces и не- Saccharomyces для брожения сусла приводит к усилению ароматических и вкусовых характеристик вин. Отмечено, что среди не сахаромицетов присутствуют организмы, синтезирующие малые количества уксусной кислоты и ацетальдегида, что благоприятно влияет на качество получаемых вин. Настоящая работа является результатом систематизации информации, касающейся некоторых аспектов использования дрожжей несахаромицетов в винодельческой промышленности, их влияния на химический состав вин. Climate change leads to an increase in the sugar content of grape must, a decrease in the concentration of organic acids, precursors of aroma-producing substances, etc. and, as a consequence, to an increase in the alcohol content, flavor imbalance and distortion of wine aroma and other problems. Even though technological approaches proposed for solution allow to achieve the goal, they often negatively affect the quality of wine. A promising alternative is using of non- Saccharomyces microorganisms with their metabolic products - glycerin, acids, mannoproteins, polysaccharides, etc. affecting the organoleptic characteristics of wine. So, using of yeast Candida spp., Metschnikowia spp., Lachancea spp. helps to reduce ethanol content in wines by 1.5-2.0% by volume. Hansensiaspora spp., Pichia spp., Starmerella spp., Torulaspora spp. and others are distinguished by a high ability to synthesize glycerin and polysaccharides. Using of yeast consortium of Saccharomyces and non- Saccharomyces for must fermentation leads to an increase in the aroma and flavor characteristics of wines. It was noted that among the non-saccharomycetes there are organisms that synthesize small amounts of acetic acid and acetaldehyde, favorably affecting the quality of wines obtained. This work is the result of information systematization concerning some aspects of using non-Saccharomyces in winemaking industry, their effect on the chemical composition of wines.
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Skotniczny, Magdalena, Paweł Satora, Katarzyna Pańczyszyn y Monika Cioch-Skoneczny. "Growth Dynamics and Diversity of Yeasts during Spontaneous Plum Mash Fermentation of Different Varieties". Foods 9, n.º 8 (4 de agosto de 2020): 1054. http://dx.doi.org/10.3390/foods9081054.
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The influence of fruit varieties on yeast ecology during spontaneous plum mash fermentation was investigated. Yeast colonies were isolated from mashes obtained from four plum varieties throughout fermentation in laboratory conditions during two consecutive years. The yeast strains were differentiated by random amplification of polymorphic DNA (RAPD-PCR) and identified by the 26S rDNA D1/D2 sequence analysis. Hanseniaspora uvarum, Metschnikowia spp. and Pichia kudriavzevii were the dominant yeasts during the early stages of plum mash fermentation, while the middle and end phases were dominated by Saccharomyces cerevisiae. The strains of Candida sake, Nakazawaea ernobii, Pichia kluyveri, Rhodotorula mucilaginosa and Wickerhamomyces anomalus were also detected in fermenting plum mashes. Metschnikowia sp. M1, H. uvarum H1 and H2 strains were detected in all samples, irrespective of the tested variety and year. Investigation of the impact of individual yeast strains on the production of volatile compounds showed the potential possibility of using them as starter cultures.
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Türkel, Sezai y Beyza Ener. "Isolation and Characterization of New Metschnikowia pulcherrima Strains as Producers of the Antimicrobial Pigment Pulcherrimin". Zeitschrift für Naturforschung C 64, n.º 5-6 (1 de junio de 2009): 405–10. http://dx.doi.org/10.1515/znc-2009-5-618.
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Metschnikowia pulcherrima is a highly effective biocontrol yeast due to its pigment pulcherrimin that accumulates in the cells and in the growth medium. Three different strains of M. pulcherrima were isolated from local grapes. The yeast isolates were characterized on the basis of their biochemical, physiological and ITS1-5.8 s rDNA-ITS2 region. Based on the obtained results, the M. pulcherrima isolates were identifi ed as new strains of M. pulcherrima. Strong antagonistic activities of the M. pulcherrima strains on the human pathogens Proteus vulgaris, Escherichia coli, Candida albicans, Candida parapsilosis, Candida krusei, and Trichosporon mucoides were determined. In addition, antagonistic effects of these M. pulcherrima strains were also tested against Aspergillus fl avus, Aspergillus fumigatus, Aspergillus niger, Trichoderma spp., Paecilomyces spp., and Bipolaris spp. and it was shown that the three different strains of M. pulcherrima also have an antagonistic effect on the growth of these fungal species at different extents. This study showed that all three strains of M. pulcherrima produce the same amount of the pigment pulcherrimin, but their antimicrobial activities on different microorganisms show important variations
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Hall, Megan E., Gregory M. Loeb, Lance Cadle-Davidson, Katherine J. Evans y Wayne F. Wilcox. "Grape Sour Rot: A Four-Way Interaction Involving the Host, Yeast, Acetic Acid Bacteria, and Insects". Phytopathology® 108, n.º 12 (diciembre de 2018): 1429–42. http://dx.doi.org/10.1094/phyto-03-18-0098-r.
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Sour rot, a disease affecting berries of cultivated Vitis spp. worldwide, has not been clearly defined. Reported symptoms of the disease include browning of the berry skin, oozing of disintegrated berry pulp, and the smell of acetic acid, all in the presence of fruit flies (Drosophila spp.). We determined acetic acid concentrations in multiple collections of symptomatic berries, isolated and identified microbes from them, and inoculated commonly isolated organisms into healthy berries with and without concurrent exposure to wild-type or axenic Drosophila melanogaster. Coinoculations combining one of several yeasts (Metschnikowia spp., Pichia spp., and a Saccharomyces sp.) plus an acetic acid bacterium (an Acetobacter sp. and Gluconobacter spp.) reproduced sour rot symptoms, defined here as decaying berries with a loss of turgor and containing acetic acid at a minimum of 0.83 g/liter, based on observed field levels. Symptoms developed only in the presence of D. melanogaster, either wild type or axenic, indicating a nonmicrobial contribution of these insects in addition to a previously suggested microbial role. We conclude that sour rot is the culmination of coinfection by various yeasts, which convert grape sugars to ethanol, and bacteria that oxidize the ethanol to acetic acid, and that this process is mediated by Drosophila spp.
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Janakiev, Tamara, Tanja Berić, Tatjana Stević, Slaviša Stanković, Jasmina Bačić, Helena Majstorović, Djordje Fira y Ivica Dimkić. "The Microbiome of the ‘Williams’ Pear Variety Grown in the Organic Orchard and Antifungal Activity by the Autochthonous Bacterial and Yeast Isolates". Microorganisms 10, n.º 7 (24 de junio de 2022): 1282. http://dx.doi.org/10.3390/microorganisms10071282.
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The total diversity of bacterial and fungal communities associated with the phyllosphere (fruits and leaves) of the ‘Williams’ pear variety was analyzed in two phenological stages during fruit development and maturation. The antagonistic potential of autochthonous bacterial and yeast isolates against phytopathogenic fungi was also evaluated. A metabarcoding approach revealed Pantoea, Sphingomonas, Hymenobacter, Massilia, and Pseudomonas as dominant bacterial constituents of the pear phyllosphere, whilst most abundant among the fungal representatives identified were Metschnikowia, Filobasidium, Aureobasidiumpullulans, Botrytis cinerea, and Taphrina. The traditional culturable approach revealed that the Pseudomonas genus with P. graminis, P. putida, and P. congelans was most prevalent. The most frequently cultivated fungal representatives belonged to the genus Fusarium with six identified species. A broad range of the antagonistic activity was detected for the Hannaella luteola and Metschnikowia pulcherrima yeasts, significantly affecting the growth of many fungal isolates in the range of 53–70%. Fusarium sporotrichioides was the most susceptible fungal isolate. The autochthonous antagonistic yeasts H. luteola and M. pulcherrima might be powerful biological control agents of postharvest diseases caused by Fusarium spp. and common pathogens like Monilinia laxa, Botrytis cinerea, Alternaria tenuissima, and Cladosporium cladosporioides.
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Karabulut, Ozgur Akgun, Joseph L. Smilanick, Franka Mlikota Gabler, Monir Mansour y Samir Droby. "Near-Harvest Applications of Metschnikowia fructicola, Ethanol, and Sodium Bicarbonate to Control Postharvest Diseases of Grape in Central California". Plant Disease 87, n.º 11 (noviembre de 2003): 1384–89. http://dx.doi.org/10.1094/pdis.2003.87.11.1384.
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The yeast Metschnikowia fructicola, ethanol, and sodium bicarbonate (SBC), alone or in combinations, were applied to table grapes on vines 24 h before harvest to control the incidence of postharvest diseases. In four experiments, all significantly reduced the total number of decayed berries caused by Botrytis cinerea, Alternaria spp., or Aspergillus niger after storage for 30 days at 1°C followed by 2 days at 20°C. In three experiments, a mean gray mold incidence (caused by B. cinerea) of 34.2 infected berries per kilogram among untreated grape was reduced by Metschnikowia fructicola at 2 × 107 CFU/ml, ethanol at 50% (vol/vol), or SBC at 2% (wt/vol) to 12.9, 8.1, or 10.6 infected berries per kilogram, respectively. Ethanol, SBC, and SO2 generator pads were similarly effective. M. fructicola effectiveness was not improved when combined with ethanol or SBC treatments. Ethanol and yeast treatments did not harm the appearance of the grapes. M. fructicola and SBC left noticeable residues, and SBC caused some visible phytotoxicity to the rachis and berries. Ethanol applied at 50% (vol/vol) reduced epiphytic fungal and bacterial populations by about 50% compared with controls. M. fructicola populations persisted on berries during storage when applied alone or after ethanol treatments, whereas SBC reduced its population significantly.
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Robledo-Leal, E., L. G. Rivera-Morales, M. P. Sangorrín, G. M. González, G. Ramos-Alfano, J. M. Adame-Rodriguez, J. M. Alcocer-Gonzalez, E. T. Arechiga-Carvajal y C. Rodriguez-Padilla. "Identification and susceptibility of clinical isolates of Candida spp. to killer toxins". Brazilian Journal of Biology 78, n.º 4 (1 de febrero de 2018): 742–49. http://dx.doi.org/10.1590/1519-6984.175635.
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Abstract 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.
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Benito, Calderón y Benito. "The Influence of Non-Saccharomyces Species on Wine Fermentation Quality Parameters". Fermentation 5, n.º 3 (30 de junio de 2019): 54. http://dx.doi.org/10.3390/fermentation5030054.
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In the past, some microbiological studies have considered most non-Saccharomyces species to be undesirable spoilage microorganisms. For several decades, that belief made the Saccharomyces genus the only option considered by winemakers for achieving the best possible wine quality. Nevertheless, in recent decades, some strains of non-Saccharomyces species have been proven to improve the quality of wine. Non-Saccharomyces species can positively influence quality parameters such as aroma, acidity, color, and food safety. These quality improvements allow winemakers to produce innovative and differentiated wines. For that reason, the yeast strains Torulaspora delbrueckii, Lachancea thermotolerans, Metschnikowia pulcherrima, Schizosaccharomyces pombe, and Pichia kluyveri are now available on the market. Other interesting species, such as Starmerella bacillaris, Meyerozyma guilliermondii, Hanseniospora spp., and others, will probably be available in the near future.
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Tufariello, Maria, Mariagiovanna Fragasso, Joana Pico, Annarita Panighel, Simone Diego Castellarin, Riccardo Flamini y Francesco Grieco. "Influence of Non-Saccharomyces on Wine Chemistry: A Focus on Aroma-Related Compounds". Molecules 26, n.º 3 (26 de enero de 2021): 644. http://dx.doi.org/10.3390/molecules26030644.
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Wine fermentation processes are driven by complex microbial systems, which comprise eukaryotic and prokaryotic microorganisms that participate in several biochemical interactions with the must and wine chemicals and modulate the organoleptic properties of wine. Among these, yeasts play a fundamental role, since they carry out the alcoholic fermentation (AF), converting sugars to ethanol and CO2 together with a wide range of volatile organic compounds. The contribution of Saccharomyces cerevisiae, the reference organism associated with AF, has been extensively studied. However, in the last decade, selected non-Saccharomyces strains received considerable commercial and oenological interest due to their specific pro-technological aptitudes and the positive influence on sensory quality. This review aims to highlight the inter-specific variability within the heterogeneous class of non-Saccharomyces in terms of synthesis and release of volatile organic compounds during controlled AF in wine. In particular, we reported findings on the presence of model non-Saccharomyces organisms, including Torulaspora delbrueckii, Hanseniaspora spp,Lachancea thermotolerans, Metschnikowia pulcherrima, Pichia spp. and Candida zemplinina, in combination with S. cerevisiae. The evidence is discussed from both basic and applicative scientific perspective. In particular, the oenological significance in different kind of wines has been underlined.
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Borren, Elliot y Bin Tian. "The Important Contribution of Non-Saccharomyces Yeasts to the Aroma Complexity of Wine: A Review". Foods 10, n.º 1 (23 de diciembre de 2020): 13. http://dx.doi.org/10.3390/foods10010013.
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Non-Saccharomyces yeast plays an important role in the initial stages of a wild ferment, as they are found in higher abundance in the vineyard than Saccharomyces cerevisiae. As such, there has been a focus in recent years to isolate these yeast species and characterize their effect on wine fermentation and subsequent aroma. This effect on wine aroma is often species and strain dependent, as the enzymatic profile of each yeast will determine which aroma compounds are formed as secondary metabolites. Semi-fermentative yeast, such as Hanseniaspora spp., Candida spp. and Metschnikowia pulcherrima, are commonly in high abundance in fresh grape must and have diverse enzymatic profiles, however they show a weak tolerance to ethanol, limiting their impact to the initial stages of fermentation. Fully fermentative non-Saccharomyces yeast, characterized by high ethanol tolerance, are often found at low abundance in fresh grape must, similar to Saccharomyces cerevisiae. Their ability to influence the aroma profile of wine remains high, however, due to their presence into the final stages of fermentation. Some fermentative yeasts also have unique oenological properties, such as Lanchancea thermotolerans and Schizosaccharomyces pombe, highlighting the potential of these yeast as inoculants for specific wine styles.
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Melvydas, Vytautas, Jurgita Svediene, Grazina Skridlaite, Jurate Vaiciuniene y Rasa Garjonyte. "In vitro inhibition of Saccharomyces cerevisiae growth by Metschnikowia spp. triggered by fast removal of iron via two ways". Brazilian Journal of Microbiology 51, n.º 4 (11 de agosto de 2020): 1953–64. http://dx.doi.org/10.1007/s42770-020-00357-3.
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Escribano-Viana, Rocío, Lucía González-Arenzana, Patrocinio Garijo, Rosa López, Pilar Santamaría y Ana Rosa Gutiérrez. "Selection Process of a Mixed Inoculum of Non-Saccharomyces Yeasts Isolated in the D.O.Ca. Rioja". Fermentation 7, n.º 3 (10 de agosto de 2021): 148. http://dx.doi.org/10.3390/fermentation7030148.
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The use of non-Saccharomyces yeasts in sequential fermentations with S. cerevisiae has been proposed to improve the organoleptic characteristics involved in the quality of wine. The present study set out to select a non-Saccharomyces inoculum from the D.O.Ca. Rioja for use in winemaking. Strains included in the study belonged to Torulaspora delbrueckii, Lachancea thermotolerans, Metschnikowia pulcherrima, Zygosaccharomyces bailii, Williopsis pratensis, Debaryomyces hansenii, Pichia kluyveri, Sporidiobolus salmonicolor, Candida spp., Cryptococcus spp. and two mixed inocula of Lachancea thermotolerans-Torulaspora delbrueckii in a 30/70 ratio. In the first stage of the process, SO2 resistance and presence of enzymatic activities related to wine aroma and wine color and fining (esterase, esterase-lipase, lipase, leucine arylamidase, valine arylamidase, cystine arylamidase, β-glucosidase, pectinase, cellulose, xylanase and glucanase) were studied. In the later stages, selection criteria such as fermentative behavior, aroma compound production or influence on phenolic compounds were studied in laboratory scale vinifications. Taking into account the results obtained in the different stages of the process, a mixed inoculum of Lachancea thermotolerans-Torulaspora delbrueckii in a 30/70 ratio was finally selected. This inoculum stood out for its high implantation capacity, the production of compounds of interest such as glycerol and lactic acid and the consequent modulation of wine acidity. Given these characteristics, the selected inoculum is suitable for the production of quality wines.
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Siavoshi, Farideh, Marzieh Sahraee, Samira Heydari, Abdolfattah Sarrafnejad, Parastoo Saniee, Atefeh Tavakolian y Sheida Heidarian. "Sugar-Rich Foods Carry Osmotolerant Yeasts with Intracellular Helicobacter Pylori and Staphylococcus spp". Middle East Journal of Digestive Diseases 12, n.º 3 (19 de julio de 2020): 182–93. http://dx.doi.org/10.34172/mejdd.2020.181.
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BACKGROUND Sugar-rich foods are of the main components of daily human meals. These foods with high sugar and low water content kill bacteria. However, osmotolerant yeasts survive and multiply. The aim of this study was to examine the occurrence of intracellular Helicobacter pylori(H. pylori) and Staphylococcus spp. in yeast isolates from sugar-rich foods. METHODS Thirty-two yeast isolates from fresh fruits, dried fruits, commercial foods, and miscellaneous foods were identified by the sequencing of amplified products of 26S rDNA. Fluorescence microscopy and LIVE/DEAD bacterial viability kit were used to examine the occurrence of live bacteria inside the yeast’s vacuole. Immunofluorescence assay was used to confirm the identity of intracellular bacteria as H. pylori and Staphylococcus. Polymerase chain reaction (PCR) was used for the detection of 16S rDNA of H. pylori and Staphylococcus in the total DNA of yeasts. RESULTS Yeasts were identified as members of seven genera; Candida, Saccharomyces, Zygosaccharomyces, Pichia, Meyerozyma, Metschnikowia, and Wickerhamomyces. Intravacuolar bacteria were stained green with a bacterial viability kit, revealing that they were alive. Immunofluorescence assay confirmed the identity of intracellular H. pylori and Staphylococcus spp. PCR results revealed that among the 32 isolated yeasts, 53% were H. pylori-positive, 6% were Staphylococcus-positive, 18.7% were positive for both, and 21.8% were negative for both. CONCLUSION Detection of H. pylori- and Staphylococcus-16S rDNA in yeast isolates from dried fruits, and commercial foods showed the occurrence of more than one kind of endosymbiotic bacterium in yeasts’ vacuoles. While the establishment of H. pylori and Staphylococcus in yeast is a sophisticated survival strategy, yeast serves as a potent bacterial reservoir.
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Blanco, Pilar y David Castrillo. "Influence of vintage, geographical location and agricultural management on yeast populations in Galician grape musts (NW Spain)". OENO One 56, n.º 4 (2 de noviembre de 2022): 65–79. http://dx.doi.org/10.20870/oeno-one.2022.56.4.4898.
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The influence of vintage, geographical location and farming system on yeast populations was evaluated in grape musts from Galicia (NW Spain) in three consecutive years. Grape samples were taken in organic and conventional vineyards from four Denominations of Origin (DOs) during the 2013, 2014 and 2015 vintages. Cultivable yeast populations were characterised at the quantitative and qualitative level. The general results show the existence of significant differences for yeast counts in musts among vintages and DOs, but not between farming systems. Given the geographical location of the grapes, the influence of vintage was significant in all DOs; however, the farming system only had a significant impact on viable yeasts in Rías Baixas, although the number of yeasts tended to be higher in organic samples than in conventional ones in most cases. Species richness was location dependent, with Rías Baixas and Ribeira Sacra showing the highest values. In addition, the type of yeasts varied between Denominations of Origin. From a total of 39 different yeast species identified, Metschnikowia spp., Hanseniaspora uvarum and Aureobasidium spp. were the prevailing species. These major yeasts were found to be widely distributed. However, species such as Issatchenkia terricola, Starmerella bacillaris and different species of Candida, Pichia and Zygosaccharomyces genera were mainly found in Rías Baixas and Ribeira Sacra DOs. In contrast, Lachancea thermotolerans was isolated in Monterrei and Ribeiro DOs only. Accordingly, the ANOSIM and PERMANOVA analyses evidenced significant differences in species richness among different DOs and, to a lesser extent, among vintages, but not between farming systems.
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Berbegal, Carmen, Mariagiovanna Fragasso, Pasquale Russo, Francesco Bimbo, Francesco Grieco, Giuseppe Spano y Vittorio Capozzi. "Climate Changes and Food Quality: The Potential of Microbial Activities as Mitigating Strategies in the Wine Sector". Fermentation 5, n.º 4 (23 de septiembre de 2019): 85. http://dx.doi.org/10.3390/fermentation5040085.
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Climate change threatens food systems, with huge repercussions on food security and on the safety and quality of final products. We reviewed the potential of food microbiology as a source of biotechnological solutions to design climate-smart food systems, using wine as a model productive sector. Climate change entails considerable problems for the sustainability of oenology in several geographical regions, also placing at risk the wine typicity. The main weaknesses identified are: (i) The increased undesired microbial proliferation; (ii) the improved sugars and, consequently, ethanol content; (iii) the reduced acidity and increased pH; (iv) the imbalanced perceived sensory properties (e.g., colour, flavour); and (v) the intensified safety issues (e.g., mycotoxins, biogenic amines). In this paper, we offer an overview of the potential microbial-based strategies suitable to cope with the five challenges listed above. In terms of microbial diversity, our principal focus was on microorganisms isolated from grapes/musts/wines and on microbes belonging to the main categories with a recognized positive role in oenological processes, namely Saccharomyces spp. (e.g., Saccharomyces cerevisiae), non-Saccharomyces yeasts (e.g., Metschnikowia pulcherrima, Torulaspora delbrueckii, Lachancea thermotolerans, and Starmerella bacillaris), and malolactic bacteria (e.g., Oenococcus oeni, Lactobacillus plantarum).
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Fernandes, Paulo, Isabel Maria Afonso, Jéssica Pereira, Rui Rocha y Ana Sofia Rodrigues. "Epiphitic Microbiome of Alvarinho Wine Grapes from Different Geographic Regions in Portugal". Biology 12, n.º 2 (18 de enero de 2023): 146. http://dx.doi.org/10.3390/biology12020146.
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Geographic location and, particularly, soil and climate exert influence on the typicality of a wine from a specific region, which is often justified by the terroir, and these factors also influence the epiphytic flora associated with the surface of the grape berries. In the present study, the microbiome associated with the surface of berries obtained from ten vineyards of the Alvarinho variety located in different geographical locations in mainland Portugal was determined and analyzed. The removal of microbial flora from the surface of the berries was carried out by washing and sonication, after which the extraction and purification of the respective DNA was carried out. High-throughput short amplicon sequencing of the fungal ITS region and the bacterial 16S region was performed, allowing for the determination of the microbial consortium associated with Alvarinho wine grapes. Analysis of α-diversity demonstrated that parcels from the Monção and Melgaço sub-region present a significantly (p < 0.05) lower fungal diversity and species richness when compared to the plots analyzed from other regions/sub-regions. The ubiquitous presence of Metschnikowia spp., a yeast with enologic potential interest in all parcels from Monção and Melgaço, was also observed.
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Checchia, Ilaria, Renato L. Binati, Eleonora Troiano, Maurizio Ugliano, Giovanna E. Felis y Sandra Torriani. "Unravelling the Impact of Grape Washing, SO2, and Multi-Starter Inoculation in Lab-Scale Vinification Trials of Withered Black Grapes". Fermentation 7, n.º 1 (23 de marzo de 2021): 43. http://dx.doi.org/10.3390/fermentation7010043.
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Wine quality is strongly affected by chemical composition and microbial population of grape must, which, in turn, are influenced by several post-harvest treatments, including grape withering. Different strategies have been suggested to manage the fermenting must microbiota, as it plays a central role in the outcomes of both spontaneous and guided fermentations. This study aimed at evaluating the impact of grape washing, SO2 addition, and selected starter culture inoculation on population dynamics, fermentation kinetics, and main oenological parameters in lab-scale trials, focusing on withered grapes usually used for Amarone production. Although grape washing treatment was effective in removing heavy metals and undesirable microorganisms from grape berry surface, inoculation of multi-starter cultures impacted more fermentation rates. Further, both grape washing and starter inoculation procedures had a remarkable impact on wine chemical characteristics, while 30 mg/L SO2 addition did not significantly affect the fermentation process. In summary, the best strategy in terms of limiting off-flavors and potentially reducing the need for SO2 addition in wine from withered grapes was the use of yeast starters, particularly mixed cultures composed by selected strains of Metschnikowia spp. and Saccharomyces cerevisiae. Application of a washing step before winemaking showed a potential to improve organoleptic characteristics of wine.
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Blanco, Pilar, David Castrillo, María José Graña, María José Lorenzo y Elvira Soto. "Evaluation of Autochthonous Non-Saccharomyces Yeasts by Sequential Fermentation for Wine Differentiation in Galicia (NW Spain)". Fermentation 7, n.º 3 (7 de septiembre de 2021): 183. http://dx.doi.org/10.3390/fermentation7030183.
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Non-Saccharomyces yeasts constitute a useful tool in winemaking because they secrete hydrolytic enzymes and produce metabolites that enhance wine quality; in addition, their ability to reduce alcohol content and/or to increase acidity can help to mitigate the effects of climatic change on wines. The purpose of this study was to evaluate the oenological traits of non-Saccharomyces yeast strains autochthonous from Galicia (NW Spain). To do that, we carried out sequential fermentation using 13 different species from the yeast collection of Estación de Viticultura e Enoloxía de Galicia (Evega) and Saccharomyces cerevisiae EC1118. The fermentation kinetics and yeast implantation were monitored using conventional methods and genetic techniques, respectively. The basic chemical parameters of wine were determined using the OIV official methodology, and the fermentative aroma compounds were determined by GC–FID. The results evidenced the limited fermentative power of these yeasts and the differences in their survival after the addition of S. cerevisiae to complete fermentation. Some strains reduced the alcohol and/or increased the total acidity of the wine. The positive effect on sensory wine properties as well as the production of desirable volatile compounds were confirmed for Metschnikowia spp. (Mf278 and Mp176), Lachancea thermotolerans Lt93, and Pichia kluyveri Pkl88. These strains could be used for wine diversification in Galicia.
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Binati, Renato L., Wilson J. F. Lemos Junior, Giovanni Luzzini, Davide Slaghenaufi, Maurizio Ugliano y Sandra Torriani. "Contribution of non-Saccharomyces yeasts to wine volatile and sensory diversity: A study on Lachancea thermotolerans, Metschnikowia spp. and Starmerella bacillaris strains isolated in Italy". International Journal of Food Microbiology 318 (abril de 2020): 108470. http://dx.doi.org/10.1016/j.ijfoodmicro.2019.108470.
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Gschwend, Florian, Andrea Braun-Kiewnick, Franco Widmer y Cosima Pelludat. "Apple Blossoms from a Swiss Orchard with Low-Input Plant Protection Regime Reveal High Abundance of Potential Fire Blight Antagonists". Phytobiomes Journal 5, n.º 2 (enero de 2021): 145–55. http://dx.doi.org/10.1094/pbiomes-04-20-0033-r.
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Erwinia amylovora causes fire blight, a serious disease of Rosaceae plants, including apple and pear. A predominant path of bacterial infection is entry through nectartodes after multiplication on the stigma. Depending on the inhibitory abilities of the native blossom microbiota, it may control the outbreak of fire blight and, therefore, may bar potential plant protection with reduced input of synthetic chemicals. Blossoms of five apple varieties in a low-input orchard, which had no fire blight history despite disease outbreaks in close proximity, were analyzed to assess bacterial and fungal communities. Metabarcoding indicated low microbial diversity and the presence of a few dominant operational taxonomic units (OTUs), including known fire blight antagonists such as Metschnikowia pulcherrima and Aureobasidium pullulans. The most dominant bacterial taxon (bOTU_01) was classified as Erwinia spp. To resolve sequences of species within bOTU_01, we used analyses of sequence variants and DNA signatures (i.e., nucleotide polymorphisms that are indicative for different species or species groups). These analyses revealed that >94.5% of the sequences of bOTU_01 derived from E. tasmaniensis, a potential E. amylovora antagonist. The latter was represented by up to 0.006% of the sequences. Cultivation-based analyses confirmed the prevalence of E. tasmaniensis. The high abundance of native potential E. amylovora antagonists likely indicates that this special set of native apple blossom microbiota counteracted the establishment of E. amylovora in this low-input orchard. This may allow for a new approach to assess possible components of synthetic apple blossom communities to mitigate fire blight infections.
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MUSGROVE, M. T., D. R. JONES, A. HINTON, K. D. INGRAM y J. K. NORTHCUTT. "Identification of Yeasts Isolated from Commercial Shell Eggs Stored at Refrigerated Temperatures". Journal of Food Protection 71, n.º 6 (1 de junio de 2008): 1258–61. http://dx.doi.org/10.4315/0362-028x-71.6.1258.
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Yeasts and molds can grow on or in eggs, causing spoilage. Washed and unwashed eggs (treatments) were collected aseptically on three separate days (replications) from a commercial processing facility and stored for 10 weeks at 4°C. Ten eggs from each treatment were sampled weekly (110 eggs per treatment per replication). Yeasts and molds were enumerated from external shell rinses by plating onto acidified potato dextrose agar. Yeast colonies were picked randomly and stored for subsequent identification by gas chromatographic analysis of fatty acid methyl esters using the MIDI Microbial Identification System. Of 688 isolates analyzed, 380 were identified to genus or species. Genera identified by this method included Candida, Cryptococcus, Hansenula, Hyphopichia, Metschnikowia, Rhodotorula, Sporobolomyces, and Torulaspora. Candida spp. accounted for 84.5% (321 of 380) of the isolate identifications. Candida famata was the most prevalent species (n = 120), followed by Candida lusitaniae (n = 38). A group of 20 isolates was subjected to molecular or biochemical analyses for comparison with the MIDI results. Biochemical tests were performed using automatic and mini systems. Results of biochemical tests and ribosomal DNA sequencing were in agreement for 11 of the isolates, but only 7 of the 20 MIDI-identified isolates were in agreement with the sequencing results. C. famata, an anamorph of Debaryomyces hansenii var. hansenii, was the most commonly identified isolate by all methods. These data indicate that there was limited correlation between results obtained with the MIDI system and the information obtained from molecular databases. However, both systems were able to correctly identify C. famata, the species most often isolated throughout egg storage.
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Martins, Viviana, Luís Costa, Rafaela Soares, Peter Ayogu, António Teixeira y Hernâni Gerós. "A catalogue of cultivable yeasts from the microbiota of grape berries cv. Vinhão and Loureiro". OENO One 56, n.º 3 (8 de agosto de 2022): 247–60. http://dx.doi.org/10.20870/oeno-one.2022.56.3.5462.
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The relevance of non-Saccharomyces native yeasts for improving the complexity of wine aroma is increasingly recognised, besides their use in a range of biotechnological applications. Previously, we used a metagenomic approach to assess the effects of vineyard calcium sprays on the microbiota of grape berries cv. Vinhão and Loureiro. In this study, we aimed at assembling a catalogue of the cultivable yeasts from grape berries of these cultivars and to investigate the direct effect of calcium and other elicitors on the isolated taxa. Seventeen unique colony morphologies were identified, and the sequencing of the region spanning the rDNA internal transcribed spacers or the rDNA D1/D2 domain revealed that they are distributed into 13 different genera. Although the cultivar and vintage influenced the taxa abundance and diversity, Aureobasidium pullulans and Hanseniaspora uvarum were the most abundant species, ubiquitously populating the fruits together with Pichia terricola, Rhodotorula glutinis, Starmerella bacillaris and Vishniacozyma heimaeyensis. The rarest genera comprised Candida, Trichosporon and Zygoascus. Analysis of yeast growth in the presence of specific elicitors revealed that Pichia spp. are the most sensitive to exogenous calcium, while Sporobolomyces roseus is the most sensitive to copper exposure. Moreover, A. pullulans, H. uvarum and S. bacillaris displayed the highest sensitivity to osmotic stress. In turn, Wickerhamomyces anomalus, Metschnikowia pulcherrima, P. fermentans, P. kluyveri and P. kudriavzevii showed mild resistance to ethanol, unlike the remaining non-Saccharomyces yeasts. Correlation networks expressing the overall yeast performance showed that H. uvarum and S. bacillaris share the strongest positive interspecies correlation, followed by the pairs P. fermentans–P. kluyveri, B. albus–R. glutinis and A. pullulans–V. heimaeyensis. The strongest negative correlations were found for the pairs P. kluyveri–S. roseus, P. terricola–W. anomalus, P. kudriavzevii–V. heimayensis, P. kluyveri–V. heimayensis, and A. pullulans–P. kluyveri. This study exposed microbial niches with a predictably common response to abiotic stress.
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Dygas, Dawid, Paulina Janicka, Joanna Berłowska y Dorota Kręgiel. "Conventional and unconventional yeasts able to grow on rapeseed meal hydrolysates". BioResources 17, n.º 2 (18 de abril de 2022): 3082–94. http://dx.doi.org/10.15376/biores.17.2.3082-3094.
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Yeast strains and appropriate hydrolysis conditions were selected for efficient single cell protein (SCP) production from waste rapeseed meal. High potential for effective biomass production was observed for Yarrowia lipolytica LOCK0264 with 10 g of rapeseed meal at 4.9 × 108 ± 1.5 × 108 (2.91 logarithmic units). The highest yeast multiplication rate was obtained for Metschnikowia pulcherrima NCYC747 with 12.5 g of rapeseed meal and with 15 g of rapeseed meal at 1.6 × 108 ± 3.8 × 107 and 4.5 × 108 ± 4.0 × 107 (2.75 and 2.86 logarithmic units, respectively).
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Vieira, Regine Helena Silva dos Fernandes, Rafael Dos Santos Rocha, Edirsana Maria Ribeiro de Carvalho, Oscarina Viana Sousa y Tereza Cristina Vasconcelos Gesteira. "Vibrio na água e sedimento de viveiros de quatro fazendas de carcinicultura no estado do Ceará, Brasil". Brazilian Journal of Veterinary Research and Animal Science 47, n.º 6 (1 de diciembre de 2010): 454. http://dx.doi.org/10.11606/issn.1678-4456.bjvras.2010.26807.
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Foram realizadas 16 coletas, oito no período chuvoso e oito no período de estio, em quatro fazendas de carcinicultura do Estado do Ceará, nos estuários dos rios Jaguaribe (fazendas A e B) e Acaraú (fazendas C e D), totalizando 32 amostras. O objetivo da pesquisa foi quantificar e identificar Vibrio spp. nas amostras de água e sedimento. Os valores máximos da Contagem Padrão em Placas (CPP) de Vibrio spp. encontrados para as amostras de água, no período chuvoso, foram de 5.10³ UFC/mL est. e, para o sedimento, de 7,5.10³ UFC/g est. No período de estio, a CPP máxima para água foi de 4,35.10² UFC/mL est. e de 3,55.10³ UFC/g est. para as amostras de sedimento. Foram obtidos 36 isolados de Vibrio: Vibrio spp. (17), V. vulnificus B1(3); V. calviensis (2), V. cholerae (2), V. litoralis (2), V. metschnikovii (2), V. agarivorans (1), V. alginolyticus (1), V. campbellii (1), V. coralliilyticus (1), V. diazotrophicus (1), V. logei (1), V. mediterranei (1), V. vulnificus B2 (1). O conhecimento da presença de espécies, nunca anteriormente isoladas em viveiros de fazendas de carcinicultura, tais como o V. coralliilyticus, V. agarivorans, V. litoralis e V. calviensis são importantes para o monitoramento microbiológico contínuo desses ambientes.
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Bühlmann, Andreas, Sandrine Kammerecker, Laurin Müller, Maja Hilber-Bodmer, Sarah Perren y Florian M. Freimoser. "Stability of Dry and Liquid Metschnikowia pulcherrima Formulations for Biocontrol Applications against Apple Postharvest Diseases". Horticulturae 7, n.º 11 (3 de noviembre de 2021): 459. http://dx.doi.org/10.3390/horticulturae7110459.
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The yeast Metschnikowia pulcherrima is frequently isolated from environmental samples and has often been reported to exhibit strong antagonistic activity against plant pathogens. In order to assess the potential of this species for its development into a plant protection product, the survival during formulation and storage were quantified and field efficacy was assessed over a period of five years. Freeze dried and liquid M. pulcherrima formulations (i.e., with skim milk powder (SMP), sucrose, glycerol, xanthan, without additives) were prepared and the number of viable cells was quantified during storage at different temperatures. Field trials against apple postharvest diseases (Neofabreae) were performed with different dry formulations. M. pulcherrima proved exceptionally stable for many months and even years. Five years of field trials with the yeast revealed variable effects, but reduced Neofabreae infections of stored apples were observed in some years. M. pulcherrima applications after prior fungicide treatments repeatedly showed an additive effect as compared to the fungicide treatments alone. In summary, M. pulcherrima exhibited highly advantageous storage properties and encouraging activity against apple postharvest rots. Further studies to identify the factors responsible for antagonistic activity in the field and survival during storage are expected to lay the foundation for the future development of a plant protection product.
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Páll, Emöke, Mihaela Niculae, Gheorghe F. Brudașcă, Rustam Kh Ravilov, Carmen Dana Șandru, Constantin Cerbu, Diana Olah et al. "Assessment and Antibiotic Resistance Profiling in Vibrio Species Isolated from Wild Birds Captured in Danube Delta Biosphere Reserve, Romania". Antibiotics 10, n.º 3 (22 de marzo de 2021): 333. http://dx.doi.org/10.3390/antibiotics10030333.
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Antimicrobial and multidrug-resistant bacteria are a major problem worldwide and, consequently, the surveillance of antibiotic-resistant bacteria and assessment of the dissemination routes are essential. We hypothesized that migratory birds, coming from various environments, would carry more numerous Vibrio strains than sedentary species, with increased risk to be passed to their contacts or environment in habitats they transit or nest in. Similarly, we presumed that strains from migratory birds will show multidrug resistance. A total of 170 oral and rectal swabs were collected from wild birds captured in different locations of the Danube Delta (Malic, Sfantu-Gheorghe, Letea Forest) and processed using standardized selective media. V. cholerae strains were confirmed by serology and molecular methods and, subsequently, their susceptibility was evaluated. The prevalence of Vibrio species by host species, habitat type, and location was interpreted. The isolated Vibrio species were identified as Vibrio cholerae 14.33%, V. fluvialis 13.33%, V. alginolyticus 12%, V. mimicus 17.33%, V. vulnificus 10.88%, with V. parahaemolyticus and V. metschnikovii (16%) also being prevalent. Of the 76 Vibrio spp. isolates, 18.42% were resistant towards at least three antimicrobials, and 81.57% demonstrated a multidrug resistance phenotype, including mainly penicillins, aminoglycosides, and macrolides. The results of the present study indicate higher numbers of Vibrio strains in migratory (74.66%) than in sedentary birds (25.33%), confirming our hypothesis. Furthermore, the increased pathogenicity of Vibrio spp. strains, isolated from wild migratory and sedentary birds, was confirmed by their increased multiple antibiotic resistance (MAR) index (0.09–0.81).
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Corrales Ramírez MSC, Lucía Constanza, María Angélica Álvarado Ospina, Lady Alexandra Castillo Fonseca y Yury Constanza Camacho Beltran. "Estudio bacteriológico de la calidad del pescado fresco, Bagre (Pseudoplatystoma sp.) y Mojarra Roja (Oreochromis sp.) comercializado en el municipio de El Colegio, Cundinamarca (Colombia)". Nova 9, n.º 16 (15 de diciembre de 2011): 149. http://dx.doi.org/10.22490/24629448.497.
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En el Municipio El Colegio, Cundinamarca, se observa la necesidad de realizar controles periódicos sobre buenas prácticas de manufactura que disminuyan el grado de contaminación que pueda estar presentándose en los expendios de pescado fresco. El análisis bacteriológico permitió confirmar ausencia de los patógenos <em>Salmonella s.p, Staphylococcus aureus, Escherichia coli y Vibrio cholerae</em>, en contraste con la presencia en un alto índice de otro tipo de enterobacterias relacionadas en su mayoría con el agua de donde proviene el pescado, como <em>C. amalonaticus y C. freundii en un 30% de las muestras; K. oxytoca, E. cloacae, </em>y <em>E. tarda</em> <em>en un 10% </em>respectivamente. Para Mojarra Roja se aisló <em>K. oxytoca, K. ozaenae, E. tarda, P. mirabilis </em>en un <em>20% </em>respectivamente <em>y V. metschnikovii </em>en un 10%; microorganismos que en elevadas cantidades pueden representar un alto riesgo para la salud pública.
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Garcia-Gonzalez, Martin, Marina Minguet-Lobato, Francisco J. Plou y Maria Fernandez-Lobato. "Molecular characterization and heterologous expression of two α-glucosidases from Metschnikowia spp, both producers of honey sugars". Microbial Cell Factories 19, n.º 1 (11 de julio de 2020). http://dx.doi.org/10.1186/s12934-020-01397-y.
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Windholtz, Sara, Emmanuel Vinsonneau, Laura Farris, Cécile Thibon y Isabelle Masneuf-Pomarède. "Yeast and Filamentous Fungi Microbial Communities in Organic Red Grape Juice: Effect of Vintage, Maturity Stage, SO2, and Bioprotection". Frontiers in Microbiology 12 (24 de diciembre de 2021). http://dx.doi.org/10.3389/fmicb.2021.748416.
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Changes are currently being made to winemaking processes to reduce chemical inputs [particularly sulfur dioxide (SO2)] and adapt to consumer demand. In this study, yeast growth and fungal diversity were investigated in merlot during the prefermentary stages of a winemaking process without addition of SO2. Different factors were considered, in a two-year study: vintage, maturity level and bioprotection by the adding yeast as an alternative to SO2. The population of the target species was monitored by quantitative-PCR, and yeast and filamentous fungi diversity was determined by 18S rDNA metabarcoding. A gradual decrease of the α-diversity during the maceration process was highlighted. Maturity level played a significant role in yeast and fungal abundance, which was lower at advanced maturity, while vintage had a strong impact on Hanseniaspora spp. population level and abundance. The presence of SO2 altered the abundance of yeast and filamentous fungi, but not their nature. The absence of sulfiting led to an unexpected reduction in diversity compared to the presence of SO2, which might result from the occupation of the niche by certain dominant species, namely Hanseniaspora spp. Inoculation of the grape juice with non-Saccharomyces yeast resulted in a decrease in the abundance of filamentous fungi generally associated with a decline in grape must quality. Lower abundance and niche occupation by bioprotection agents were observed at the overripened stage, thus suggesting that doses applied should be reconsidered at advanced maturity. Our study confirmed the bioprotective role of Metschnikowia pulcherrima and Torulaspora delbrueckii in a context of vinification without sulfites.
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Castrillo Cachón, David, Eva Rabuñal Crego, Noemi Neira González y Pilar Blanco Camba. "Yeast diversity on grapes from Galicia, NW Spain: biogeographical patterns and the influence of the farming system". OENO One 53, n.º 3 (9 de septiembre de 2019). http://dx.doi.org/10.20870/oeno-one.2019.53.3.2379.
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Aim: Organic viticulture has increased in recent decades, worldwide. Farming system influences grapes’ yeast populations and, therefore, fermentation dynamics and wine quality. This work aims to study yeast diversity on grapes and musts from organic and conventional production in different areas within Galicia (NW Spain) and to evaluate the existence of yeast geographic patterns (microbial terroir) in this region.Methods and results: During the 2015 vintage, 42 grape samples were collected from four Denominations of Origin (DOs) in Galicia. Representative cultivable yeasts from grapes and must samples were isolated and characterised at the species level in the Estación de Viticultura e Enoloxía de Galicia (EVEGA-AGACAL). Results were compared among DOs and between organic and conventional production. A total of 33 yeast species were identified. Organic production showed27.3% higher species richness than conventional production. Accordingly, diversity indexes (H′ and E) were higher under organic cultures compared to conventional production. The highest yeast diversity was found in Rías Baixas and Ribeira Sacra DOs. The predominant yeasts were Aureobasidium spp., Metschnikowia spp., Hanseniaspora uvarum and Cryptococcus spp., although their proportion varied depending on the farming system and location. Furthermore, important differences were observed in minor species, which appeared mainly in organic cultivation. In addition, a biogeographic pattern was found: Issatchenkia terricola and Starmerella bacillaris were isolated in Rías Baixas and Ribeira Sacra DOs, whereas Lachancea thermotolerans was ligated to Monterrei and Ribeiro DOs. ANOSIM, PERMANOVA and PCA analysis confirmed this differentiation.Conclusions: The results indicated that an organic farming system favoured yeast diversity on grapes and musts. Moreover, species distribution made it possible to establish a biogeographic pattern in the yeast population that could be associated to a particular microbial terroir and wine typicality.Significance and impact of the study: This study reports for the first time a survey on yeast diversity on grapes and musts from organic and conventional production in different areas within Galicia. The results highlighted the role of organic culture as a tool to preserve yeast richness and the existence of biogeographic patterns of yeast communities in vineyards in NW Spain, which could contribute to wine typicality of specific areas.
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Ljunggren, Joel, Felipe Borrero-Echeverry, Amrita Chakraborty, Tobias U. T. Lindblom, Erik Hedenström, Maria Karlsson, Peter Witzgall y Marie Bengtsson. "Yeast Volatomes Differentially Affect Larval Feeding in an Insect Herbivore". Applied and Environmental Microbiology 85, n.º 21 (23 de agosto de 2019). http://dx.doi.org/10.1128/aem.01761-19.
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ABSTRACT Yeasts form mutualistic interactions with insects. Hallmarks of this interaction include provision of essential nutrients, while insects facilitate yeast dispersal and growth on plant substrates. A phylogenetically ancient chemical dialogue coordinates this interaction, where the vocabulary, the volatile chemicals that mediate the insect response, remains largely unknown. Here, we used gas chromatography-mass spectrometry, followed by hierarchical cluster and orthogonal partial least-squares discriminant analyses, to profile the volatomes of six Metschnikowia spp., Cryptococcus nemorosus, and brewer’s yeast (Saccharomyces cerevisiae). The yeasts, which are all found in association with insects feeding on foliage or fruit, emit characteristic, species-specific volatile blends that reflect the phylogenetic context. Species specificity of these volatome profiles aligned with differential feeding of cotton leafworm (Spodoptera littoralis) larvae on these yeasts. Bioactivity correlates with yeast ecology; phylloplane species elicited a stronger response than fruit yeasts, and larval discrimination may provide a mechanism for establishment of insect-yeast associations. The yeast volatomes contained a suite of insect attractants known from plant and especially floral headspace, including (Z)-hexenyl acetate, ethyl (2E,4Z)-deca-2,4-dienoate (pear ester), (3E)-4,8-dimethylnona-1,3,7-triene (DMNT), linalool, α-terpineol, β-myrcene, or (E,E)-α-farnesene. A wide overlap of yeast and plant volatiles, notably floral scents, further emphasizes the prominent role of yeasts in plant-microbe-insect relationships, including pollination. The knowledge of insect-yeast interactions can be readily brought to practical application, as live yeasts or yeast metabolites mediating insect attraction provide an ample toolbox for the development of sustainable insect management. IMPORTANCE Yeasts interface insect herbivores with their food plants. Communication depends on volatile metabolites, and decoding this chemical dialogue is key to understanding the ecology of insect-yeast interactions. This study explores the volatomes of eight yeast species which have been isolated from foliage, from flowers or fruit, and from plant-feeding insects. These yeasts each release a rich bouquet of volatile metabolites, including a suite of known insect attractants from plant and floral scent. This overlap underlines the phylogenetic dimension of insect-yeast associations, which according to the fossil record long predate the appearance of flowering plants. Volatome composition is characteristic for each species, aligns with yeast taxonomy, and is further reflected by a differential behavioral response of cotton leafworm larvae, which naturally feed on foliage of a wide spectrum of broad-leaved plants. Larval discrimination may establish and maintain associations with yeasts and is also a substrate for designing sustainable insect management techniques.
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Munandar, Hendra, Dien Arista Anggorowati, Varian Fahmi y Syafriyadi Hafid. "DIVERSITY AND ABUNDANCE OF CULTURABLE VIBRIONACEAE IN THE REARING TANKS OF THREE DIFFERENT CONSUMER TYPES OF AQUACULTURE COMMODITIES". Marine Research in Indonesia 46, n.º 1 (23 de febrero de 2022). http://dx.doi.org/10.14203/mri.v46i1.582.
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Vibrio spp. bacteria species are heterotrophic and halophilic bacteria, which are commonly found in various habitats such as brackish, marine waters and animals. They are widely used as an indicator of water quality and cultured animal health. This study investigates the diversity and abundance of Vibrionaceae populations in the rearing water of three distinct consumer types of aquaculture commodities, namely abalone, lobster and sea cucumber, during six months sampling. We isolated Vibrionaceae bacteria from the rearing tanks of three different consumer types of aquaculture commodities. We then inoculated 100 µL of undiluted to 10-5 diluted water samples onto petriplate containing selective Thiosulphate Bile Salt Sucrose agar (TCBS). We characterised bacteria colonies based on the biochemical test for identification. Vibrio metschnikovii was the predominant bacteria species in abundance value from the rearing water of cultured lobster and sea cucumber. Meanwhile, Vibrio anguillarum was the most noticeable bacteria species in abundance from the rearing water of cultured abalone. These data provide information and facilitate the risk assessment of these pathogenic Vibrio species in aquaculture commodities.