Search results for "Zygosaccharomyces"
showing 10 items of 20 documents
Microbial Enzymes: Relevance for Winemaking
2017
Production of wine from grape juice is predominantly the result of complex enzymatic reactions. The primary bioconversion of grape sugar to ethanol and CO2 by the yeast Saccharomyces cerevisiae is catalyzed by cytosolic enzymes. In spontaneous must fermentations, also strains of Saccharomyces bayanus or interspecies hybrids may dominate, probably because of better adaptation to specific environmental conditions. In addition, various enzymes released into the must influence the final composition, color, and sensory properties of wines. These enzymes originate from the grape itself, from epiphytic fungi like Botrytis cinerea, and from yeasts and bacteria associated with vineyards and wine cel…
Kluyveromyces osmophilus is not a synonym of Zygosaccharomyces mellis; reinstatement as Zygosaccharomyces osmophilus comb. nov.
2020
Kluyveromyces osmophilus, a single-strain species isolated from Mozambique sugar, has been treated a synonym of Zygosaccharomyces mellis. Analyses of D1/D2 LSU rRNA gene sequences confirmed that the species belongs to the genus Zygosaccharomyces but showed it to be distinct from strains of Z. mellis. During studies of yeasts associated with stingless bees in Brazil, nine additional isolates of the species were obtained from unripe and ripe honey and pollen of Scaptotrigona cfr. bipunctata, as well as ripe honey of Tetragonisca angustula. The D1/D2 sequences of the Brazilian isolates were identical to those of the type strain of K. osmophilus CBS 5499 (=ATCC 22027), indicating that they rep…
A method to discriminate between the Candida stellata and Saccharomyces cerevisiae in mixed fermentation on WLD and lysine agar media
2016
This paper presents a simple method to distinguish between Candida stellata and Saccharomyces cerevisiae yeasts during microbiological analyses. The method is based on differential yeast growth on a medium containing cycloheximide and a medium containing lysine as only nitrogen source (lysine agar). The cycloheximide resistance of 45 yeast strains belonging to Candida stellata, Hanseniaspora uvarum, Hanseniaspora guilliermondii, Metschnikowia pulcherrima, Torulaspora delbrueckii, Zygosaccharomyces bailii, Kluyveromyces thermotolerans and Zygoascus hellenicus, and 14 strains of Saccharomyces cerevisiae and Saccharomyces bayanus on WL nutrient agar, was assayed. Cycloheximide resistance is ch…
The glucose-dependent transport of L-malate in Zygosaccharomyces bailii.
1984
Zygosaccharomyces bailii possesses a constitutive malic enzyme, but only small amounts of malate are decomposed when the cells ferment fructose. Cells growing anaerobically on glucose (glucose cells) decompose malate, whereas fructose cells do not. Only glucose cells show an increase in the intracellular concentration of malate when suspended in a malate-containing solution. The transport system for malate is induced by glucose, but it is repressed by fructose. The synthesis of this transport system is inhibited by cycloheximide. Of the two enantiomers L-malate is transported preferentially. The transport of malate by induced cells is not only inhibited by addition of fructose but also inac…
Rapid characterization of wild and collection strains of the genus Zygosaccharomyces according to mitochondrial DNA patterns
1997
Several wild and collection strains of the genus Zygosaccharomyces were characterized using a rapid and simple method of restriction analysis of mitochondrial DNA. Patterns obtained with three endonucleases (HaeIII, HinfI and RsaI) made it possible to differentiate each species and to identify the wild strains, isolated from the same spoiled concentrated must, as belonging to the species Z. rouxii. The HinfI restriction enzyme produced a strain-specific pattern which allowed us to recognize that the seven wild isolates belonged to only three strains.
Molecular characterisation of the species of the genus Zygosaccharomyces.
2003
The restriction fragments polymorphisms of the mitochondrial DNA and the PCR fragment that comprised the internal transcribes spacers and the 5.8S rRNA gene, together with the electrophoretic karyotypes of 40 strains from the 10 species of the genus Zygosaccharomyces, including the new species Z. lentus were examined. The RFLP's of the ITS-5.8S region showed a specific restriction pattern for each species, including the new species Z. lentus. The only exception were the species Z. cidri and Z. fermentati that produced identical restriction profiles. The electrophoretic chromosome patterns confirmed the differences between the species of this genus, including the phylogenetic closest species…
Transgenic Expression of a Toxin-Coding Killer Virus of the Yeast Zygosaccharomyces bailii in Saccharomyces cerevisiae: Genetic Evidence for a Possib…
1996
The killer toxin-secreting yeast Zygosaccharomyces bailii 412 contains two cytoplasmically inherited double-stranded RNA (dsRNA) viruses (ZbV-L, ZbV-M) responsible for the expression of a killer phenotype in its infected host. While ZbV-L functions as a classical helpervirus by providing capsid (cap) and RNA polymerase functions (cap/pol) necessary for packaging and replication of both viruses, M-dsRNA-containing killer viruses (ZbV-M) are satellites of ZbV-L that contain the genetic information for toxin production only. Both viruses were shown to be sufficient to confer the Z. bailii killer phenotype upon transfected spheroplasts of a S. cerevisiae non-killer strain, resulting in toxin-se…
Production of the Sicilian distillate “ Spiritu re fascitrari ” from honey by-products: An interesting source of yeast diversity
2017
The “Spiritu re fascitrari” (SRF) is a typical Sicilian distillate obtained from the by-products of traditional process of honey production. Although some alcoholic fermentation of honey based products have been described, the present research represents the first investigation on the yeast ecology and the physico-chemical characteristics of honey by-products subjected to an alcoholic fermentation followed by distillation. All samples collected during manufacturing process were analysed for the count of total, osmophilic and osmotolerant yeasts. The honeycombs and equipment surfaces showed the presence of yeasts that was 1.7 and 1.1 Log (CFU/mL), respectively. After enrichment, yeast popula…
How hexoses and inhibitors influence the malate transport system in Zygosaccharomyces bailii
1988
When grown in fructose or glucose the cells of Zygosaccharomyces bailii were physiologically different. Only the glucose grown cells (glucose cells) possessed an additional transport system for glucose and malate. Experiments with transport mutants had lead to the assumption that malate and glucose were transported by one carrier, but further experiments proved the existence of two separate carrier systems. Glucose was taken up by carriers with high and low affinity. Malate was only transported by an uptake system and it was not liberated by starved malate-loaded cells, probably due to the low affinity of the intracellular anion to the carrier. The uptake of malate was inhibited by fructose…
Insights Into the Cultivable Microbial Ecology of “Manna” Ash Products Extracted From Fraxinus angustifolia (Oleaceae) Trees in Sicily, Italy
2019
Microbial communities characterizing a specific food matrix, generally, strongly contribute to both its composition, and properties for food applications. To our knowledge, this is the first study to investigate the cultivable microbial ecology of Sicilian "Manna" ash products in order to acquire new information on the hygienic quality, shelf-life and potential application of this traditional food. To this purpose, several manna samples belonging to different commercial categories were collected and subjected to the analysis of bacteria, yeasts, and filamentous fungi. Furthermore, an investigation of the sugar content and physicochemical parameters was performed. The results of our study fo…