• Marcha
• ethanol production attributes
• stress exclusion tests
• yeasts

• Antioxidant capacity
• Non-Saccharomyces yeast
• Oenology
• Yeast derivatives

• Antioxidants/chemistry
• Antioxidants/analysis
• Antioxidants/metabolism
• Metabolome
• Saccharomyces cerevisiae/metabolism
• Chromatography, High Pressure Liquid
• Biphenyl Compounds/chemistry
• Picrates/antagonists & inhibitors
• Glutathione/metabolism
• Glutathione/analysis

• aroma formation
• co-inoculation
• enological parameters
• sensory profile
• volatile compounds

• Wine/analysis
• Saccharomyces cerevisiae
• Torulaspora
• Odorants
• Bentonite
• Fermentation
• Acetates/analysis

• Byproducts
• Ethanol
• Fermentation
• Non-Saccharomyces
• Wine

Cell membranes provide a selective semi-permeable barrier to the passive transport of molecules. This property differs greatly between organisms. While the cytoplasmic membrane of bacterial cells is highly permeable for weak acids and glycerol, yeasts can maintain large concentration gradients. Here we show that such differences can arise from the physical state of the plasma membrane. By combining stopped-flow kinetic measurements with molecular dynamics simulations, we performed a systematic analysis of the permeability of a variety of small molecules through synthetic membranes of different lipid composition to obtain detailed molecular insight into the permeation mechanisms. While membrane thickness is an important parameter for the permeability through fluid membranes, the largest differences occur when the membranes transit from the liquid-disordered to liquid-ordered and/or to gel state, which is in agreement with previous work on passive diffusion of water. By comparing our results with in vivo measurements from yeast, we conclude that the yeast membrane exists in a highly ordered and rigid state, which is comparable to synthetic saturated DPPC-sterol membranes.

Membrane permeability of small molecules depends on the composition of the lipid bilayer. Here, authors compare permeability measured on membranes in different physical states and conclude that the yeast membrane exists in a highly ordered phase.

The use of yeast starter cultures consisting of a blend of Saccharomyces cerevisiae and non-Saccharomyces yeasts has increased in recent years as a mean to address consumers’ demands for diversified wines. However, this strategy is currently limited by the lack of a comprehensive knowledge regarding the factors that determine the balance between the yeast-yeast interactions and their responses triggered in complex environments. Our previous studies demonstrated that the strain Hanseniaspora guilliermondii UTAD222 has potential to be used as an adjunct of S. cerevisiae in the wine industry due to its positive impact on the fruity and floral character of wines. To rationalize the use of this yeast consortium, this study aims to understand the influence of production factors such as sugar and nitrogen levels, fermentation temperature, and the level of co-inoculation of H. guilliermondii UTAD222 in shaping fermentation and wine composition. For that purpose, a Central Composite experimental Design was applied to investigate the combined effects of the four factors on fermentation parameters and metabolites produced. The patterns of variation of the response variables were analyzed using machine learning methods, to describe their clustered behavior and model the evolution of each cluster depending on the experimental conditions. The innovative data analysis methodology adopted goes beyond the traditional univariate approach, being able to incorporate the modularity, heterogeneity, and hierarchy inherent to metabolic systems. In this line, this study provides preliminary data and insights, enabling the development of innovative strategies to increase the aromatic and fermentative potential of H. guilliermondii UTAD222 by modulating temperature and the availability of nitrogen and/or sugars in the medium. Furthermore, the strategy followed gathered knowledge to guide the rational development of mixed blends that can be used to obtain a particular wine style, as a function of fermentation conditions.

• aroma production
• central composite design
• nitrogen
• non-Saccharomyces yeasts
• sugar
• supervised and unsupervised machine learning
• temperature

• Chardonnay wine
• Inoculation time
• Metabolomics
• Sequential fermentation
• Yeast-yeast interaction

The conversion of grape juice to wine starts with complex yeast communities consisting of strains that have colonised the harvested grape and/or reside in the winery environment. As the conditions in the fermenting juice gradually become inhibitory for most species, they are rapidly overgrown by the more adaptable Saccharomyces strains, which then complete the fermentation. However, there are environmental factors that even Saccharomyces cannot cope with. We show that when the sugar content is extremely high, osmotolerant yeasts, usually considered as “spoilage yeasts“, ferment the must. The examination of the yeast biota of 22 botrytised Tokaj Essence wines of sugar concentrations ranging from 365 to 752 g∙L⁻¹ identified the osmotolerant Zygosaccharomyces rouxii, Candida (Starmerella) lactis-condensi and Candida zemplinina (Starmerella bacillaris) as the dominating species. Ten additional species, mostly known as osmotolerant spoilage yeasts or biofilm-producing yeasts, were detected as minor components of the populations. The high phenotypical and molecular (karyotype, mtDNA restriction fragment length polymorphism (RFLP) and microsatellite-primed PCR (MSP-PCR)) diversity of the conspecific strains indicated that diverse clones of the species coexisted in the wines. Genetic segregation of certain clones and interactions (antagonism and crossfeeding) of the species also appeared to shape the fermenting yeast biota.

• Candida
• Tokaj
• Zygosaccharomyces
• antagonism
• fermentation
• genetic diversity
• osmotolerant
• wine
• yeast

• Bioethanol
• Biorefinery
• Fermentation
• Microalgae
• Nitrogen source

• cider
• fermentation
• gas chromatography
• hydrogen sulfide
• juice concentrate
• volatile esters

The aim of this study was to evaluate the application of cocoa pulp as an adjunct for malt in beer production. The cocoa pulp was analyzed for humidity, proteins, lipids, sugars, total soluble solids, organic acids, and minerals. A study was carried out to reduce the cocoa pulp viscosity by enzymatic depectinization, making its use viable in beer production. The cocoa pulp showed relevant quantities of compounds important in fermentation, such as sugars, acids, and minerals. In fermentation using the adjunct, the proportions of pulp used were 10, 30, and 49%. A significant difference was found between the adjunct and all-malt worts. The 30% cocoa pulp concentration as an adjunct for malt in the fermentation medium contributed the most to the fermentative performance of the yeasts at both 15 and 22°C based on the consumption of apparent extract (°Plato), ethanol production, and cellular growth.

Membrane lipids act as solvents and functional cofactors for integral membrane proteins. The yeast plasma membrane is unusual in that it may have a high lipid order, which coincides with low passive permeability for small molecules and a slow lateral diffusion of proteins. Yet, membrane proteins whose functions require altered conformation must have flexibility within membranes. We have determined the molecular composition of yeast plasma membrane lipids located within a defined diameter of model proteins, including the APC-superfamily lysine transporter Lyp1. We now use the composition of lipids that naturally surround Lyp1 to guide testing of lipids that support the normal functioning of the transporter, when reconstituted in vesicles of defined lipid composition. We find that phosphatidylserine and ergosterol are essential for Lyp1 function, and the transport activity displays a sigmoidal relationship with the concentration of these lipids. Non-bilayer lipids stimulate transport activity, but different types are interchangeable. Remarkably, Lyp1 requires a relatively high fraction of lipids with one or more unsaturated acyl chains. The transport data and predictions of the periprotein lipidome of Lyp1 support a new model in which a narrow band of lipids immediately surrounding the transmembrane stalk of a model protein allows conformational changes in the protein.

• APC superfamily
• Saccharomyces cerevisiae
• amino acids
• membrane transport
• yeast plasma membrane

Yeast tolerates a low pH and high solvent concentrations. The permeability of the plasma membrane (PM) for small molecules is low and lateral diffusion of proteins is slow. These findings suggest a high degree of lipid order, which raises the question of how membrane proteins function in such an environment. The yeast PM is segregated into the Micro-Compartment-of-Can1 (MCC) and Pma1 (MCP), which have different lipid compositions. We extracted proteins from these microdomains via stoichiometric capture of lipids and proteins in styrene-maleic-acid-lipid-particles (SMALPs). We purified SMALP-lipid-protein complexes by chromatography and quantitatively analyzed periprotein lipids located within the diameter defined by one SMALP. Phospholipid and sterol concentrations are similar for MCC and MCP, but sphingolipids are enriched in MCP. Ergosterol is depleted from this periprotein lipidome, whereas phosphatidylserine is enriched relative to the bulk of the plasma membrane. Direct detection of PM lipids in the 'periprotein space' supports the conclusion that proteins function in the presence of a locally disordered lipid state.

• S. cerevisiae
• Saccharomyces cerevisiae
• biochemistry
• chemical biology
• eisosome
• lipidomics
• membrane domains
• membrane proteins
• plasma membrane

• applied microbiology
• microbial ecology

• Fermentation
• Food Microbiology
• Fruit and Vegetable Juices/microbiology
• Microbiota
• Saccharomyces cerevisiae/classification
• Saccharomyces cerevisiae/metabolism
• Temperature
• Vitis
• Wine

• YeSVitE consortium (FP7-IRSES-2013-GA no. 612441)
• Wine Industry Network for Expertise and Technology (Winetech), grant SU IWBT 16/02 National Research Foundation-Technology and Human Resources for Industry Programme (grant number TP14080184824)

In winemaking, non-Saccharomyces yeast species contribute important organoleptic complexity. Current interest focuses on abundant and dominant strains characteristically present in the early phase of spontaneous alcoholic fermentations. Non-Saccharomyces species are particularly relevant in Port wine production such that the fermentation is prematurely stopped, after the metabolism of only one half of the available sugar, through fortification with aguardente. This work aimed to isolate, identify and characterize non-Saccharomyces species present in spontaneously fermenting Port. To accomplish these goals, yeasts were isolated from a selection of frozen must samples (2012–2016 harvests), using a pre-screening process choosing only the best candidates based on the organoleptic quality of the corresponding fortified wine. From five hundred non-Saccharomyces isolates, twelve species were identified. The three most abundant species, Hanseniaspora uvarum, Lachancea thermotolerans, and Metschnikowia pulcherrima, representing 89% of the isolates, exhibited particularly high diversity with high growth performance variability when exposed to typical stress conditions associated with common enological parameters. Less abundant species included Issatchenkia orientalis, Torulaspora delbrueckii, Hanseniaspora vineae, Hanseniaspora osmophila, Candida zemplinina, Rhodotorula mucilaginosa, Hanseniaspora guilliermondii, Issatchenkia occidentalis, and Zygosaccharomyces bisporus. This is the first study providing insights into the identification and characterization of non-Saccharomyces species responsible for spontaneous Port wine production.

• Port wine
• native yeasts
• non-Saccharomyces
• strain characterization
• wine yeasts

Non-Saccharomyces yeasts have received increased attention by researchers and winemakers, due to their particular contributions to the characteristics of wine. In this group, Saccharomycodes ludwigii is one of the less studied species. In the present study, a native S. ludwigii strain, UTAD17 isolated from the Douro wine region was characterized for relevant oenological traits. The genome of UTAD17 was recently sequenced. Its potential use in winemaking was further evaluated by conducting grape-juice fermentations, either in single or in mixed-cultures, with Saccharomyces cerevisiae, following two inoculation strategies (simultaneous and sequential). In a pure culture, S. ludwigii UTAD17 was able to ferment all sugars in a reasonable time without impairing the wine quality, producing low levels of acetic acid and ethyl acetate. The overall effects of S. ludwigii UTAD17 in a mixed-culture fermentation were highly dependent on the inoculation strategy which dictated the dominance of each yeast strain. Wines whose fermentation was governed by S. ludwigii UTAD17 presented low levels of secondary aroma compounds and were chemically distinct from those fermented by S. cerevisiae. Based on these results, a future use of this non-Saccharomyces yeast either in monoculture fermentations or as a co-starter culture with S. cerevisiae for the production of wines with greater expression of the grape varietal character and with flavor diversity could be foreseen.

• Saccharomycodes ludwigii
• mixed-culture
• non-Saccharomyces
• wine aroma
• wine fermentation

• Glycerol
• Non-Saccharomyces
• Sequential fermentation
• Unripe grape must

• Aroma
• Cold fermentation
• Ethanol reduction
• Glycerol
• Hybridization, mixed populations yeasts
• S. uvarum, S. kudriavzevii, winemaking
• Saccharomyces yeast

• Climate Change
• Fermentation
• Food Technology
• Fruit
• Vitis
• Wine/analysis
• Wine/microbiology
• Yeasts/classification
• Yeasts/physiology

Yeasts secrete a large diversity of compounds during alcoholic fermentation, which affect growth rates and developmental processes, like filamentous growth. Several compounds are produced during aromatic amino acid metabolism, including aromatic alcohols, serotonin, melatonin, and tryptamine. We evaluated the effects of these compounds on growth parameters in 16 different wine yeasts, including non-Saccharomyces wine strains, for which the effects of these compounds have not been well-defined. Serotonin, tryptamine, and tryptophol negatively influenced yeast growth, whereas phenylethanol and tyrosol specifically affected non-Saccharomyces strains. The effects of the aromatic alcohols were observed at concentrations commonly found in wines, suggesting a possible role in microbial interaction during wine fermentation. Additionally, we demonstrated that aromatic alcohols and ethanol are able to affect invasive and pseudohyphal growth in a manner dependent on nutrient availability. Some of these compounds showed strain-specific effects. These findings add to the understanding of the fermentation process and illustrate the diversity of metabolic communication that may occur among related species during metabolic processes.

• aromatic alcohols
• invasive growth
• non-Saccharomyces
• pseudohyphal growth
• quorum sensing
• serotonin
• tryptamine

• Non-Saccharomyces yeasts
• PCR- DGGE
• Plate count
• Pre-fermentative cold soak
• Quantitative PCR (qPCR)
• Saccharomyces cerevisiae

Hanseniaspora uvarum is one of the most abundant yeast species found on grapes and in grape must, at least before the onset of alcoholic fermentation (AF) which is usually performed by Saccharomyces species. The aim of this study was to characterize the genetic and phenotypic variability within the H. uvarum species. One hundred and fifteen strains isolated from winemaking environments in different geographical origins were analyzed using 11 microsatellite markers and a subset of 47 strains were analyzed by AFLP. H. uvarum isolates clustered mainly on the basis of their geographical localization as revealed by microsatellites. In addition, a strong clustering based on year of isolation was evidenced, indicating that the genetic diversity of H. uvarum isolates was related to both spatial and temporal variations. Conversely, clustering analysis based on AFLP data provided a different picture with groups showing no particular characteristics, but provided higher strain discrimination. This result indicated that AFLP approaches are inadequate to establish the genetic relationship between individuals, but allowed good strain discrimination. At the phenotypic level, several extracellular enzymatic activities of enological relevance (pectinase, chitinase, protease, β-glucosidase) were measured but showed low diversity. The impact of environmental factors of enological interest (temperature, anaerobia, and copper addition) on growth was also assessed and showed poor variation. Altogether, this work provided both new analytical tool (microsatellites) and new insights into the genetic and phenotypic diversity of H. uvarum, a yeast species that has previously been identified as a potential candidate for co-inoculation in grape must, but whose intraspecific variability had never been fully assessed.

• Hanseniaspora uvarum
• intraspecific diversity
• microsatellites
• phenotypic screening
• wine

• Animals
• Anti-Bacterial Agents/biosynthesis
• Biofuels
• Butanols/metabolism
• Ethanol/metabolism
• Fermentation
• Humans
• Saccharomyces cerevisiae/metabolism

• BB/F003471/1 Biotechnology and Biological Sciences Research Council
• BBF0034711 Biotechnology and Biological Sciences Research Council

• Biodiversity
• Candida zemplinina
• Mixed fermentation
• Non-Saccharomyces yeast
• Starmerella bacillaris
• Wine fermentation

• Low temperature
• Prefermentative cold soak
• Red wine
• Sensory analysis
• Yeast

• Aromatized coffee
• Pectinolytic enzymes
• Pichia fermentans
• Saccharomyces sp.
• Wet processing

• Candida
• Helicobacter pylori
• Intracellular
• Vacuole

• Adaptation, Physiological
• Animals
• Bacterial Proteins/genetics
• Bacterial Proteins/metabolism
• Candida/genetics
• Candida/metabolism
• Candida/physiology
• Female
• Food Microbiology
• Gene Expression Regulation, Bacterial
• Gene Expression Regulation, Fungal
• Helicobacter Infections/metabolism
• Helicobacter Infections/microbiology
• Helicobacter Infections/transmission
• Helicobacter pylori/genetics
• Helicobacter pylori/metabolism
• Helicobacter pylori/pathogenicity
• Host-Pathogen Interactions
• Humans
• Infectious Disease Transmission, Vertical
• Microbial Viability
• Mouth/microbiology
• Stomach/microbiology
• Symbiosis
• Vacuoles/microbiology
• Vagina/microbiology
• Virulence
• Virulence Factors/genetics
• Virulence Factors/metabolism