Search results for "Zygosaccharomyces"
showing 10 items of 20 documents
Investigation of a Killer Strain of Zygosaccharomyces Bailii
1993
Summary: The yeast Zygosaccharomyces bailii strain 412 was found to liberate a killer toxin (KT412) lethal to sensitive strains of Saccharomyces cerevisiae and Candida glabrata. Culture supernatants of the killer strain were concentrated by ultrafiltration and the extracellular protein was purified by gel filtration and ion-exchange chromatography. Gel filtration and SDS-PAGE of the electrophoretically homogeneous killer protein indicated an apparent molecular mass of 10 kDa. The killer toxin KT412 is probably not glycosylated since it did not show any detectable carbohydrate structures. KT412 was bound to sensitive but not to resistant yeast cells. The mannan, and not the glucan, fraction …
Non-conventional yeasts from fermented honey by-products: Focus on Hanseniaspora uvarum strains for craft beer production
2021
The increasing interest in novel beer productions focused on non-Saccharomyces yeasts in order to pursue their potential in generating groundbreaking sensory profiles. Traditional fermented beverages represent an important source of yeast strains which could express interesting features during brewing. A total of 404 yeasts were isolated from fermented honey by-products and identified as Saccharomyces cerevisiae, Wickerhamomyces anomalus, Zygosaccharomyces bailii, Zygosaccharomyces rouxii and Hanseniaspora uvarum. Five H. uvarum strains were screened for their brewing capability. Interestingly, Hanseniaspora uvarum strains showed growth in presence of ethanol and hop and a more rapid growth…
Selection and molecular characterization of wine yeasts isolated from the ‘El Penedès’ area (Spain)
2000
Abstract A study of the microbiota present during the wine fermentation of five grape varieties from the ‘El Penedes’ area (Spain) was carried out to select autochthonous yeast strains for industrial wine production. In this study we identified members of the genera Candida, Dekkera, Hanseniaspora, Kluyveromyces, Torulaspora, Zygosaccharomyces and Saccharomyces in wine fermentation microbiota. Strains of Saccharomyces cerevisiae, as responsible agents of the alcoholic fermentation, were considered for a selection protocol. In this work we applied different enological criteria for selection, but previously we have characterized and differentiated Saccharomyces isolates by molecular methods t…
Rational selection of non-Saccharomyces wine yeasts for mixed starters based on ester formation and enological traits
2008
Thirty-eight yeast strains belonging to the genera Candida, Hanseniaspora, Pichia, Torulaspora and Zygosaccharomyces were screened for ester formation on synthetic microbiological medium. The genera Hanseniaspora and Pichia stood out as the best acetate ester producers. Based on the ester profile Hanseniaspora guilliermondii 11027 and 11102, Hanseniaspora osmophila 1471 and Pichia membranifaciens 10113 and 10550 were selected for further characterization of enological traits. When growing on must H. osmophila 1471, which displayed a glucophilic nature and was able to consume more than 90% of initial must sugars, produced levels of acetic acid, medium chain fatty acids and ethyl acetate, wit…
Killer toxin-secreting double-stranded RNA mycoviruses in the yeasts Hanseniaspora uvarum and Zygosaccharomyces bailii.
1994
Killer toxin-secreting strains of the yeasts Hanseniaspora uvarum and Zygosaccharomyces bailii were shown to contain linear double-stranded RNAs (dsRNAs) that persist within the cytoplasm of the infected host cell as encapsidated virus-like particles. In both yeasts, L- and M-dsRNAs were associated with 85-kDa major capsid protein, whereas the additional Z-dsRNA (2.8 kb), present only in the wild-type Z. bailii killer strain, was capsid protein, whereas the additional Z-dsRNA (2.8 kb), present only in the wild-type Z. bailii killer strain, was shown to be encapsidated by a 35-kDa coat protein. Although Northern (RNA) blot hybridizations indicated that L-dsRNA from Z. bailii is a LA species,…
Exoenzymes of Wine Microorganisms
2008
The production of wine from grape juice is predominantly the result of enzymatic reactions. The enzymes originate from the grape itself, from epiphytic fungi like Botrytis cinerea colonizing the grape surface and finally from yeasts and bacteria growing in the must until termination of alcoholic fermentation. Especially nonSaccharomyces yeasts, also called “wild” yeasts, belonging to the genera Kloeckera, Candida, Debaryomyces, Rhodotorula, Pichia, Zygosaccharomyces, Hanseniaspora, Kluyveromyces, and Metschnikowia produce and secrete several enzymes (esterases, glycosidases, lipases, glucanases, proteases, cellulases, etc.) to the periplasmatic space and the medium where they may interact w…
Formation of l(-)malate by Saccharomyces cerevisiae during fermentation
1988
When grown in a synthetic medium most of the 51 strains of the genera Saccharomyces, Saccharomycodes, Zygosaccharomyces and Schizosaccharomyces investigated formed l-malate during fermentation. The quantity varied between 0.1 and 2.6 g malate per liter. Two strains of Saccharomyces cerevisiae synthesized malate at a rate of about 1.5 g/l. Malate was liberated during the growth phase and not metabolized during the stationary phase. Optimum malate formation was observed at a sugar concentration of about 20% (w/v), at pH 5 and at suboptimal nitrogen concentrations of less than 300 mg N/liter. Of the amino acids aspartate and glutamate were most favourable. If ammonium salts were used as the ni…
Über den Abbau von L-Äpfelsäure durch Hefen verschiedener Gattungen mit Malatenzym
1974
Summary (1) The aerobic assimilation of malic acid is not a character of certain yeast genera or species as was shown by testing more than 300 different strains. Single strains of the following-species were found to grow on malic acid as the only carbon source: Candida pulcherrima, C. utilis, C. mycoderma, Torulopsis famata, Pichia membranaefaciens, P. wickerhamii, Hansenula capsulata, Trigonopsis variabilis , and Zygosaccharomyces chevalieri . (2) During fermentation C. pulcherrima and T. famata decompose up to 40% and C. utilis up to 80% of the L-malic acid that is present in the medium. (3) L-Malic acid is decomposed to CO 2 and the corresponding amounts of ethanol or pyruvate by cell fr…
Impact of Starmerella bacillaris and Zygosaccharomyces bailii on ethanol reduction and Saccharomyces cerevisiae metabolism during mixed wine fermenta…
2021
AbstractThe bulk of grape juice fermentation is carried out by the yeast Saccharomyces cerevisiae, but non-Saccharomyces yeasts can modulate many sensorial aspects of the final products in ways not well understood. In this study, some of such non-conventional yeasts were screened as mixed starter cultures in a fermentation defined medium in both simultaneous and sequential inoculations. One strain of Starmerella bacillaris and another of Zygosaccharomyces bailii were chosen by their distinct phenotypic footprint and their ability to reduce ethanol levels at the end of fermentation, particularly during simultaneous vinification. S. bacillaris losses viability strongly at the end of mixed fer…
Influence of the storage conditions on some physicochemical and mycological parameters of honey
1994
The authors studied the changes in yeast and mould counts, pH, free and lactone acidity, colour and sugar composition undergone by honeys with water contents of 169, 188 and 220 g kg-1 on storage at refrigeration temperature (4–7°C), room temperature and 28°C for two years. Of the solid culture media assayed, honey agar and osmophilic medium fostered yeast growth while malt-extract agar and yeast-extract-malt-extract agar allowed for better development of filamentous fungi. The yeasts isolated belonged to the genera Saccharomyces, Schizosaccharomyces and Zygosaccharomyces, while filamentous moulds were of the genera Aspergillus, Penicillium, Fusarium and Alternaria. The honeys studied under…