Transcriptome and Metabolome Analyses of Aroma Differences between Chardonnay and a Chardonnay Bud Sport.

Chardonnay is one of the most popular white grape wine varieties in the world, but this wine lacks typical aroma, considered a sensory defect. Our research group identified a Chardonnay bud sport with typical muscat characteristics. The goal of this work was to discover the key candidate genes related to muscat characteristics in this Chardonnay bud sport to reveal the mechanism of muscat formation and guide molecular design breeding. To this end, HS-SPME-GC-MS and RNA-Seq were used to analyze volatile organic compounds and the differentially expressed genes in Chardonnay and its aromatic bud sport. Forty-nine volatiles were identified as potential biomarkers, which included mainly aldehydes and terpenes. Geraniol, linalool, and phenylacetaldehyde were identified as the main aroma components of the mutant. The GO, KEGG, GSEA, and correlation analysis revealed HMGR, TPS1, TPS2, TPS5, novel.939, and CYP450 as key genes for terpene synthesis. MAO1 and MAO2 were significantly downregulated, but there was an increased content of phenylacetaldehyde. These key candidate genes provide a reference for the development of functional markers for muscat varieties and also provide insight into the formation mechanism of muscat aroma.

Curse or blessing: Growth- and laccase-modulating properties of polyphenols and their oxidized derivatives on Botrytis cinerea.

Infection of grapevines with the grey mold pathogen Botrytis cinerea results in severe problems for winemakers worldwide. Browning of wine is caused by the laccase-mediated oxidation of polyphenols. In the last decades, Botrytis management has become increasingly difficult due to the rising number of resistances and the genetic variety of Botrytis strains. During the search for sustainable fungicides, polyphenols showed great potential to inhibit fungal growth. The present study revealed two important aspects regarding the effects of grape-specific polyphenols and their polymerized oxidation products on Botrytis wild strains. On the one hand, laccase-mediated oxidized polyphenols, which resemble the products found in infected grapes, showed the same potential for inhibition of growth and laccase activity, but differed from their native forms. On the other hand, the impact of phenolic compounds on mycelial growth is not correlated to the effect on laccase activity. Instead, mycelial growth and relative specific laccase activity appear to be modulated independently. All phenolic compounds showed not only inhibitory but also inductive effects on fungal growth and/or laccase activity, an observation which is reported for the first time. The simultaneous inhibition of growth and laccase activity demonstrated may serve as a basis for the development of a natural botryticide. Yet, the results showed considerable differences between genetically distinguishable strains, impeding the use of a specific phenolic compound against the genetic variety of wild strains. The present findings might have important implications for future understanding of Botrytis cinerea infections and sustainable Botrytis management including the role of polyphenols.

Organoleptic modulation functions and physiochemical characteristics of mannoproteins: Possible correlations and precise applications in modulating color evolution and orthonasal perception of wines.

Mannoproteins have traditionally been recognized as effective wine organoleptic modulators, however, ambiguous understanding of the relationship between their organoleptic functions and physiochemical characteristics often lead to inappropriate application in winemaking. To reveal the possible role the physiochemical characteristics of mannoproteins play in modulating wine color and aroma properties, three water-soluble mannoproteins (MP1, MP2, MP3) with different physiochemical characteristics have been prepared, and accelerated red wine aging, malvidin pigments formation experiments, accelerated aroma release experiments have been designed to observe their organoleptic modulating functions in this research. Results suggest that the phenolic/chromatic stability of red wines could be enhanced by MP3, probably due to its low steric hindrance potential, high reactivity, and good hydro-alcoholic stability conferred by its high Mannan/Glucan ratio (8.68), abundant hydrophobic/hydrophilic amino acids (65.29 % of total protein), and low/medium molecular weight level (30.71-57.77 kDa), respectively, which protected the phenolic compounds and promoted the formation of pyranoanthocyanins. Mannoproteins could modulate the volatility of aroma compounds by expelling or retention effects, which depended on the duration of mannoprotein application (the expelling effect was firstly observed possibly because of the significant adsorption of free H2O by MPs) and the types of mannoproteins. MP1 and MP2 were prone to retain and expel aroma compounds, respectively, probably due to their medium/high molecular weight levels (60.48-135.39 kDa) that conferred abundant interacting sites, and the high proportion of hydrophobic and hydrophilic components in MP1 (97.71 % polysaccharides of total mannoprotein, 34.58 % hydrophobic amino acids of total protein) and MP2 (97.96 % polysaccharides of total mannoprotein, 28.36 % hydrophobic amino acids of total protein) guaranteed a relatively higher interacting frequency with aroma compounds and free H2O molecules, respectively.

Emotional response to sherry wines and its relationship with emotional intelligence, level of expertise and gender.

Emotional elicitation during wine consumption is a complex fenomena based on subjective experience and influence by physiological, cognitive and behavioural changes. The present study used a quasi-experimental design to examine consumers' emotional responses during blind tastings of sherry wines, considering variables such as consumer experience, gender and Emotional Intelligence (EI). 66 participants were classified as non-expert (34) and expert (32) consumers to participate in blind tastings. Their emotional responses were measured using the EsSense25 Scale and the Perceived Emotional Intelligence was assessed through the Trait Meta-Mood Scale. Few differences were observed on emotional elicitation based on gender or consumer experience (non-expert vs expert), however the interaction of these variables was a good predictor of emotional response variance. Wine type also has an effect on emotional response, emphasising the role of sherry wine characteristics in consumer emotions. Furthermore, the Emotional Attention, one of the three dimensions of Emotional Intelligence, was found as a good predictor for the emotional responses to wine consumption. This relationship may be a key factor in understanding the differences between responsible consumption and excessive consumption, as indicated by research focused on binge drinking.

Exploring the Potential Mechanisms of Zhu-Ye-Qing Wine in Preventing Cardiovascular and Cerebrovascular Diseases Based on Network Pharmacology.

Cardiovascular and cerebrovascular disease (CCVD) is a complex disease with a long latency period, and the most effective diagnosis and treatment methods are risk assessment and preventive interventions before onset. According to traditional Chinese medicine (TCM), Zhu-Ye-Qing wine (ZYQW) has the effect of invigorating blood and removing blood stasis. However, whether ZYQW can improve the progression of CCVD has not been reported. This study aims to explore the possible mechanism of ZYQW on CCVD through network pharmacology, and finally 249 potential targets of ZYQW and 2080 potential targets of CCVD are obtained. The key targets mainly include MAPK3, TP53, RELA, MAPK1 and AKT1. The main KEGG pathways include TNF signaling pathway, lipid and atherosclerosis pathway signaling pathway. The components in ZYQW are identified by ultra-performance liquid chromatography-mass spectrometry (UHPLC-CQE-CQE-MS/MS). Through network pharmacology, molecular docking and molecular dynamics simulation, the potential key components and prevention mechanisms of ZYQW in the prevention of CCVD are determined. ZYQW may be an effective and safe health food for the prevention of CCVD, providing guidance and basis for the further development of medicinal foods.

Amelioration of Smoke Taint in Wine via Addition of Molecularly Imprinted Polymers during or after Fermentation.

The adsorbents used to remove taint compounds from wine can also remove constituents that impart desirable color, aroma, and flavor attributes, whereas molecularly imprinted polymers (MIPs) are tailor-made to selectively bind one or more target compounds. This study evaluated the potential for MIPs to ameliorate smoke taint in wine via removal of volatile phenols during or after fermentation. The addition of MIPs to smoke-tainted Pinot Noir wine (for 24 h with stirring) achieved 35-57% removal of guaiacol, 4-methylguaiacol, cresols, and phenol, but <10% of volatile phenol glycoconjugates were removed and some wine color loss occurred. Of the MIP treatments that were subsequently applied to Semillon and Merlot fermentations or wine, MIP addition post-inoculation of yeast yielded the best outcomes, both in terms of volatile phenol removal and wine sensory profiles. Despite some impact on other aroma volatiles and red wine color, the findings demonstrate that MIPs can ameliorate smoke-tainted wine.

Eco-friendly solvent-based liquid-liquid extraction of phenolic acids from winery wastewater streams.

This study proposes liquid-liquid extraction (LLE) for the recovery of phenolic acids from winery wastewater replacing common volatile organic compounds (VOCs) with environmentally friendly solvents. On one hand, terpenes (α-pinene and p-cymene) and terpenoids (eucalyptol and linalool) were selected as green solvents and compared to common VOCs (ethyl acetate or 1-butanol). On the other hand, gallic acid (GA), vanillic acid (VA), syringic acid (SA) and caffeic acid (CA) were selected as phenolic acids to be recovered. The extraction performance was evaluated under different operation conditions: solvent-to-feed ratio, initial concentration of phenolic acids and temperature. This work also evaluated the back-extraction whole process global recovery and solvent regeneration, by means of aqueous NaOH solution. Eucalyptol has shown the highest overall global extraction performance (21.07 % for GA, 93.21 % for VA, 78.79 % for SA, and 80.57 % for CA) and lower water solubility compared to the best performing VOC solvent (1-butanol). Therefore, eucalyptol can be a potential eco-friendly solvent to replace VOCs for sustainable phenolic acid recovery from winery wastewater. Finally, to ensure a clean water stream after the LLE, the traces of solvent were completely removed by electrooxidation with boron-doped diamond anode at a current density of 422.54 A/m2.

Pesticides and winemaking: A comprehensive review of conventional and emerging approaches.

The use of pesticides in viticulture may play a crucial role in ensuring the health and quality of grapes. This review analyzes the most common pesticides used, illustrating their classification and toxicity, and their variations throughout the winemaking process. Fungicides are generally harmless or mildly toxic, whereas insecticides are classified as either highly or moderately hazardous. Potential alternatives to synthetic pesticides in wine production are also reviewed, thereby including biopesticides and biological agents. Analytical methods for detecting and quantifying pesticide residues in wine are then described, including liquid chromatography and gas chromatography coupled with mass spectrometry. This review also discusses the impact of the winemaking process on pesticide content. Pesticides with strong hydrophobicity were more likely to accumulate in solid byproducts, whereas hydrophilic pesticides were distributed more in the liquid phase. Grape's skin contains lipids, so hydrophobic pesticides adsorb strongly on grape surfaces and the clarification has been shown to be effective in the reduction of hydrophobic compounds. Therefore, the final wine could have more quantities of hydrophilic pesticides. Alcoholic fermentation has been shown to be crucial in pesticide dissipation. However, pesticide residues in wine have been shown an antagonistic effect on yeasts, affecting the safety and quality of wine products. Therefore, proteomic and genomic analyses of yeast growth are reviewed to understand the effects of pesticides on yeast during fermentation. The last section describes new effective methods used in removing pesticides from grapes and wine, thereby improving product quality and reducing harmful effects.

Engineering a GPCR-based yeast biosensor for a highly sensitive melatonin detection from fermented beverages.

Melatonin is a multifunctional molecule with diverse biological roles that holds great value as a health-promoting bioactive molecule in any food product and yeast's ability to produce it has been extensively demonstrated in the last decade. However, its quantification presents costly analytical challenges due to the usual low concentrations found as the result of yeast metabolism. This study addresses these analytical challenges by optimizing a yeast biosensor based on G protein-coupled receptors (GPCR) for melatonin detection and quantitation. Strategic genetic modifications were employed to significantly enhance its sensitivity and fluorescent signal output, making it suitable for detection of yeast-produced melatonin. The optimized biosensor demonstrated significantly improved sensitivity and fluorescence, enabling the screening of 101 yeast strains and the detection of melatonin in various wine samples. This biosensor's efficacy in quantifying melatonin in yeast growth media underscores its utility in exploring melatonin production dynamics and potential applications in functional food development. This study provides a new analytical approach that allows a rapid and cost-effective melatonin analysis to reach deeper insights into the bioactivity of melatonin in fermented products and its implications for human health. These findings highlight the broader potential of biosensor technology in streamlining analytical processes in fermentation science.

Activation of the yeast Retrograde Response pathway by adaptive laboratory evolution with S-(2-aminoethyl)-L-cysteine reduces ethanol and increases glycerol during winemaking.

BACKGROUND: Global warming causes an increase in the levels of sugars in grapes and hence in ethanol after wine fermentation. Therefore, alcohol reduction is a major target in modern oenology. Deletion of the MKS1 gene, a negative regulator of the Retrograde Response pathway, in Saccharomyces cerevisiae was reported to increase glycerol and reduce ethanol and acetic acid in wine. This study aimed to obtain mutants with a phenotype similar to that of the MKS1 deletion strain by subjecting commercial S. cerevisiae wine strains to an adaptive laboratory evolution (ALE) experiment with the lysine toxic analogue S-(2-aminoethyl)-L-cysteine (AEC). RESULTS: In laboratory-scale wine fermentation, isolated AEC-resistant mutants overproduced glycerol and reduced acetic acid. In some cases, ethanol was also reduced. Whole-genome sequencing revealed point mutations in the Retrograde Response activator Rtg2 and in the homocitrate synthases Lys20 and Lys21. However, only mutations in Rtg2 were responsible for the overactivation of the Retrograde Response pathway and ethanol reduction during vinification. Finally, wine fermentation was scaled up in an experimental cellar for one evolved mutant to confirm laboratory-scale results, and any potential negative sensory impact was ruled out. CONCLUSIONS: Overall, we have shown that hyperactivation of the Retrograde Response pathway by ALE with AEC is a valid approach for generating ready-to-use mutants with a desirable phenotype in winemaking.

Investigating biological mechanisms of colour changes in sustainable food systems: The role of Starmerella bacillaris in white wine colouration using a combination of genomic and biostatistics strategies.

This study explores the biological mechanisms behind colour changes in white wine fermentation using different strains of Starmerella bacillaris. We combined food engineering, genomics, machine learning, and physicochemical analyses to examine interactions between S. bacillaris and Saccharomyces cerevisiae. Significant differences in total polyphenol content were observed, with S. bacillaris fermentation yielding 6 % higher polyphenol content compared to S. cerevisiae EC1118. Genomic analysis identified 12 genes in S. bacillaris with high variant counts that could impact phenotypic properties related to wine color. Notably, SNP analysis revealed numerous missense and synonymous variants, as well as stop-gained and start-lost variants between PAS13 and FRI751, suggesting changes in metabolic pathways affecting pigment production. Besides that, high upstream gene variants in SSK1 and HIP1R indicated potential regulatory changes influencing gene expression. Fermentation trials revealed FRI751 consistently showed high antioxidant activity and polyphenol content (Total Polyphenol: 299.33 ± 3.51 mg GAE/L, DPPH: 1.09 ± 0.01 mmol TE/L, FRAP: 0.95 ± 0.02 mmol TE/L). PAS13 exhibited a balanced profile, while EC1118 had lower values, indicating moderate antioxidant activity. The Weibull model effectively captured nitrogen consumption dynamics, with EC1118 serving as a reliable benchmark. The scale parameter delta for EC1118 was 23.04 ± 2.63, indicating moderate variability in event times. These findings highlight S. bacillaris as a valuable component in sustainable winemaking, offering an alternative to chemical additives for maintaining wine quality and enhancing colours profiles. This study provides insights into the biotechnological and fermented food systems applications of yeast strains in improving food sustainability and supply chain, opening new avenues in food engineering and microbiology.

The color stability of artificial white spot lesions treated with resin infiltration after exposure to staining beverages.

BACKGROUND: To evaluate the effect of staining beverages on the color-changing of resin-infiltrated artificial white spot lesions (WSLs). METHODS: Thirty-five artificial WSLs were created by pH cycling on flat bovine teeth specimens. The WSLs were treated with resin infiltration and were divided into five groups based on staining beverages: artificial saliva, coffee, wine, green tea, and Coca-Cola. These specimens were subjected to a 28-day exposure to the respective beverages. Color stability was assessed using a spectrophotometer at different time points: baseline, after 7, 14, 21, and 28 days of exposure, and repolishing. The color difference (∆E) between each time point and the baseline was calculated. Statistical analysis was performed using two-way measures ANOVA with a significance level of p = 0.05. RESULTS: All resin-infiltrated specimens exposed to staining beverages for 7 days exhibited more significant color changes than those exposed to artificial saliva. The color change patterns varied based on the type of beverage. The color alterations intensified with extended immersion in the wine and Coca-Cola groups, while there were no significant differences in the color of specimens after 28 days of immersion in the coffee and green tea groups. However, after cleaning with pumice powder, all specimens showed significantly reduced color changes compared to those observed after 28 days of immersion, except those immersed in coffee. CONCLUSIONS: Exposure of resin-infiltrated bovine tooth specimens to staining beverages resulted in a significant color alteration as the immersion time increased. However, the staining effect could be minimized by cleaning with pumice powder, except for the coffee group. CLINICAL RELEVANCE: After resin infiltration treatment, patients should be advised to minimize the consumption of colored beverages to prevent staining that could impact esthetic appearance.

[Effect of compatibility of Corni Fructus before and after wine-processing with Astragali Radix on plasma metabolomics in diabetic nephropathy rats based on UHPLC-Q-TOF-MS/MS].

Based on the processing and compatibility, this study explored the effects of components in Corni Fructus(CF) and Astragali Radix(AR) on plasma metabolomics in diabetic nephropathy rats. SD rats were randomly divided into four groups and diabetic nephropathy rat model was induced by high-fat diet combined with 30 mg·kg~(-1) streptozotocin(STZ). Histopathological observations of kidney tissue sections of rats in each group were conducted using HE, PAS, and Masson staining. Ultra-high performance liquid chromatography-quadrupole time-of-flight tandem mass spectrometry(UHPLC-Q-TOF-MS/MS) metabolomics method was employed to investigate the effects of CF before and after wine-processing combined with AR-related components on plasma metabolites in diabetic nephropathy rats. After drug treatment, kidney tissue damage and interstitial collagen fiber deposition area in diabetic nephropathy rats were improved to varying degrees(P<0.001). The detection results of plasma metabolomics showed that 71 biomarkers related to the pathogenesis of diabetic nephropathy were identified in diseased rats, mainly involving linoleic acid metabolism, caffeine metabolism, glycerophospholipid metabolism, phenylalanine, tyrosine and tryptophan biosynthesis, arachidonic acid metabolism, phenylalanine metabolism, retinol metabolism, and ether lipid metabolism. After drug intervention, 26 of them were significantly downregulated, with better efficacy observed in precision processed herb-pair group(P-CG_5). This study elucidated from the perspective of plasma metabolomics that P-CG_5 could improve metabolic disorders in diabetic nephropathy through pathways such as phenylalanine, tyrosine and tryptophan biosynthesis, phenylalanine metabolism, and caffeine metabolism, providing theoretical support and experimental basis for the clinical application of CF and AR compatibility in traditional Chinese medicine.

Cu2(OH)3NO3 nanozyme sensor array for the discrimination of multiple sulfides in food.

In the food industry, sulfides are commonly used as preservatives and flavor regulators. However, long-term excessive intake of sulfides can lead to serious health problems. Therefore, developing efficient sulfide detection methods is particularly important. Here, we have effectively synthesized a novel bifunctional copper hydroxide nitrate (Cu2(OH)3NO3) nanozyme with outstanding peroxidase-like and laccase-like behaviors in basic deep eutectic solvents (DES). Because the various types of sulfides have diverse regulatory effects on the two catalytic behaviors of Cu2(OH)3NO3, a two channel nanozyme sensor array based on the peroxidase-like and laccase-like behaviors of Cu2(OH)3NO3 was constructed and successfully used for the identification of six kinds of sulfides (Na2S, Na2S2O3, Na2SO3, Na2SO4, NaHSO3, and Na2S2O8). Remarkably, the sensor array has achieved successful discrimination among six sulfides present in wine, egg, and milk samples. Finally, the sensor array has successfully distinguished and differentiated three actual samples (wine, egg, and milk). This study is of great significance in promoting the efficient construction of array units and improving the effective identification of sulfides in complex food samples.

Smartphone-Assisted and Optical Quantification of Copper and Glucose Using Palm Wine-Tailored Carbon Dots and Their Multiple Logic Gate Application.

In this work, potassium, sulfur, nitrogen, and chlorine self-doped carbon dots (CDs) were hydrothermally synthesized using palm wine as a carbon source. The palm wine-derived CDs (PW-CDs) are amorphous in nature and displayed an average particle size of 4.19 ± 0.89 nm. The as-synthesized CDs are used to fabricate a photoluminescent sensing probe to simultaneously detect Cu2+ and glucose via the "Turn ON-OFF-ON" mechanism. The PL quenching mechanism of PW-CDs enables the selective and sensitive detection of Cu2+ ions with a detection limit (LOD) of 0.8 ppb (4.7 nM). The sensing probe quantified Cu2+ in tap water, drinking water, and e-waste samples to prove its viability. Using CDs to quantify copper in e-waste leachate samples is a novel approach as no prior instances of such application have been reported. The system's performance is considered to be highly reproducible due to the relative standard deviation being <6.64%, along with excellent recoveries within the range of 93.24-109.86%. The quenched PL can be recovered by introducing glucose into the PW-CD + Cu2+ system; this strategy is employed to quantify glucose with a LOD of 0.11 ppm (0.61 µM). The feasibility of this sensor was confirmed by the determination of glucose in actual human plasma specimens of diabetic patients. It is to be noted that these samples were neither diluted nor spiked with glucose. The developed PW-CD + Cu2+ sensing system yields satisfactory recoveries of 93.45-107.37%. This probe was also incorporated into a smartphone-based sensing platform to detect Cu2+ and glucose with desirable recoveries. The proposed smartphone-based sensing platform is flexible, reliable, and accurate, making it suitable for resource-constrained areas. Furthermore, based on the effect of Cu2+ ions and glucose on the PL response and absorbance spectra of PW-CDs, four logic gates (YES, IMPLICATION, NOT, and OR) were designed, and PW-CDs were also used for cell imaging applications.

Fishwaste Derived Hydroxyapatite Nanostructure Combined with Black Rice Wine for Potential Antioxidant and Antimicrobial Response.

Hospital-acquired infection remains a serious threat globally, due to development of resistance to conventional antibiotics, which necessitates the urge for alternative therapy. Green nanotechnology has emerged as a holistic approach to address antibiotic resistance by combining environmental sustainability with improved therapeutic outcome. Nanostructure hydroxyapatite (HAP) has received significant attention in therapeutic and regenerative purposes due to its porous scaffold structure and biocompatible nature. In the present study, hydroxyapatite (HAP) nanoparticle was fabricated from the fish scale waste of red snapper fish. Black rice wine (BRW) was extracted from black rice commonly termed as Karupu kavuni/forbidden rice known for its nutritious effects. The present study focused on encapsulation of BRW within HAP nanoparticles (HAP@BRW) and evaluated its potential against nosocomial infections. Spectral and microscopic characterization of HAP@BRW revealed uniform encapsulation of BRW in HAP nanoparticles, aggregated irregular-shaped morphology of size 117.6 nm. Maximum release of BRW (72%) within 24 h indicates HAP as suitable drug delivery system suitable for biomedical applications. Antimicrobial studies revealed that HAP@BRW exhibited potent bactericidal effect against MRSA, MSSA, and Pseudomonas aeruginosa. Furthermore, HAP@BRW significantly inhibited the biofilm forming ability of MSSA and P. aeruginosa. Rich antioxidant property of HAP@BRW might be due to the presence of rich source of total polyphenolic, flavonoid, and anthocyanin content in BRW. In vitro and in vivo toxicity studies revealed biocompatible nature of HAP@BRW. Antibiofilm, antimicrobial, antioxidant, and biocompatible nature of HAP@BRW makes it a promising candidate for coating medical implants to avoid implant-associated infections and nosocomial infections.

Detailed three-dimensional analyses of tyloses in oak used for bourbon and wine barrels through X-ray computed tomography.

American white (Quercus alba L.) oak casks have been used for liquid storage for centuries. Their use in aged spirits is critical to imparting flavor and mouthfeel to the final product. The reason that barrels retain liquid has been hypothesized to be the result of abundant physiological structures called tyloses in parenchyma tissues and medullary rays in white oak. Using non-destructive X-ray computed tomography (XRCT) imaging, we reveal an unprecedented view of tylose structure and quantify the pore-filling capacity of tyloses in white oak that underscores the liquid retention we observe in casks. We show that pores of white oaks are filled with sevenfold higher tylose volume compared to northern red oak (Q. rubra), consistent with prior literature that casks made from white oak retain liquid while red oak fails to do so. We propose that XRCT represents a methodological standard for observing these complex structures and should be employed to understand the many questions related to liquid losses from casks, cultural treatment of casks, and the influence of climate change on oak tyloses in the future.

Physical cell-cell contact elicits specific transcriptomic responses in wine yeast species.

Fermenting grape juice provides a habitat for a well-mapped and evolutionarily relevant microbial ecosystem consisting of many natural or inoculated strains of yeasts and bacteria. The molecular nature of many of the ecological interactions within this ecosystem remains poorly understood, with the partial exception of interactions of a metabolic nature such as competition for nutrients and production of toxic metabolites/peptides. Data suggest that physical contact between species plays a significant role in the phenotypic outcome of interspecies interactions. However, the molecular nature of the mechanisms regulating these phenotypes remains unknown. Here, we present a transcriptomic analysis of physical versus metabolic contact between two wine relevant yeast species, Saccharomyces cerevisiae and Lachancea thermotolerans. The data show that these species respond to the physical presence of the other species. In S. cerevisiae, physical contact results in the upregulation of genes involved in maintaining cell wall integrity, cell wall structural components, and genes involved in the production of H2S. In L. thermotolerans, HSP stress response genes were the most significantly upregulated gene family. Both yeasts downregulated genes belonging to the FLO family, some of which play prominent roles in cellular adhesion. qPCR analysis indicates that the expression of some of these genes is regulated in a species-specific manner, suggesting that yeasts adjust gene expression to specific biotic challenges or interspecies interactions. These findings provide fundamental insights into yeast interactions and evolutionary adaptations of these species to the wine ecosystem.IMPORTANCEWithin the wine ecosystem, yeasts are the most relevant contributors to alcoholic fermentation and wine organoleptic characteristics. While some studies have described yeast-yeast interactions during alcoholic fermentation, such interactions remain ill-defined, and little is understood regarding the molecular mechanisms behind many of the phenotypes observed when two or more species are co-cultured. In particular, no study has investigated transcriptional regulation in response to physical interspecies cell-cell contact, as opposed to the generally better understood/characterized metabolic interactions. These data are of direct relevance to our understanding of microbial ecological interactions in general while also creating opportunities to improve ecosystem-based biotechnological applications such as wine fermentation. Furthermore, the presence of competitor species has rarely been considered an evolutionary biotic selection pressure. In this context, the data reveal novel gene functions. This, and further such analysis, is likely to significantly enlarge the genome annotation space.

Influence of different stress factors during the elaboration of grape must's pieddecuve on the dynamics of yeast populations during alcoholic fermentation.

The pieddecuve (PdC) technique involves using a portion of grape must to undergo spontaneous fermentation, which is then used to inoculate a larger volume of must. This allows for promoting autochthonous yeasts present in the must, which can respect the typicality of the resulting wine. However, the real impact of this practice on the yeast population has not been properly evaluated. In this study, we examined the effects of sulphur dioxide (SO2), temperature, ethanol supplementation, and time on the dynamics and selection of yeasts during spontaneous fermentation to be used as PdC. The experimentation was conducted in a synthetic medium and sterile must using a multi-species yeast consortium and in un-inoculated natural grape must. Saccharomyces cerevisiae dominated both the PdC and fermentations inoculated with commercial wine yeast, displaying similar population growth regardless of the tested conditions. However, using 40 mg/L of SO2 and 1% (v/v) ethanol during spontaneous fermentation of Muscat of Alexandria must allowed the non-Saccharomyces to be dominant during the first stages, regardless of the temperature tested. These findings suggest that it is possible to apply the studied parameters to modulate the yeast population during spontaneous fermentation while confirming the effectiveness of the PdC methodology in controlling alcoholic fermentation.

Development of a qPCR method for classification of botrytized grape berries originated from Tokaj wine region.

One of the best-known Hungarian products on world wine market is Aszú, which belongs to the family of Tokaj wine specialties and is made from aszú berries. An important condition for the formation of aszú berries is the noble rot of technologically mature grapes, which is caused by Botrytis cinerea. At the same time botrytized sweet wines are produced not only in Hungary, but in many locations of wine-producing areas of Europe as well as in certain wine growing regions of other continents. The determination of botrytization is mostly based on sensory evaluations, which is a highly subjective procedure and largely depends on the training and experience of the evaluator. Currently, the classification of aszú berries (class I and class II) is based only on visual inspection and determination of sugar content. Based on these facts the primary goal of our work was to develop a qPCR assay capable for objective rating and classification of aszú berries. The developed qPCR is highly specific and sensitive as can clearly distinguish between B. cinerea and other filamentous fungi and yeast species occur on grapes. Moreover, it is suitable for categorizing berries colonized by B. cinerea to varying degrees. Thus, the developed qPCR method can be a useful technique for classification of the grape berries into four quality groups: healthy, semi-shrivelled, Aszú Class II and Aszú Class I.