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Journal of Dairy Science Dec 2023The possible contribution of brine-derived microflora to the sensory attributes of cheese is still a rather unexplored field. In this study, 365 bacteria and 105 yeast...
The possible contribution of brine-derived microflora to the sensory attributes of cheese is still a rather unexplored field. In this study, 365 bacteria and 105 yeast strains isolated from 11 cheese brines were qualitatively tested for proteolytic and lipolytic activities, and positive strains were identified by sequencing. Among bacteria, Staphylococcus equorum was the most frequent, followed by Macrococcus caseolyticus and Corynebacterium flavescens. As for yeasts, Debaryomyces hansenii, Clavispora lusitaniae, and Torulaspora delbrueckii were most frequently identified. A total of 38% of bacteria and 59% of yeasts showed at least 1 of the metabolic activities tested, with lipolytic activity being the most widespread (81% of bacteria and 95% of yeasts). Subsequently 15 strains of bacteria and 10 yeasts were inoculated in a curd-based medium and assessed via headspace-solid phase microextraction coupled with gas chromatography-mass spectrometry to determine their volatilome. After a 30-d incubation at 12°C, most strains showed a viability increase of about 2 log cfu/mL, suggesting good adaptability to the cheese environment. A total of 26 compounds were detected in the headspace, carbonyl compounds and alcohols being the major contributors to the volatile profile of the curd-based medium. Multivariate analysis was carried out to elucidate the overall differences in volatiles produced by selected strains. Principal component analysis and hierarchical clustering analysis demonstrated that the brine-related microorganisms were separated into 3 different groups, suggesting their different abilities to produce volatile compounds. Some of the selected strains have been shown to have interesting aromatic potential and to possibly contribute to the sensory properties of cheese.
Topics: Animals; Salts; Yeasts; Bacteria; Gas Chromatography-Mass Spectrometry; Cheese
PubMed: 37641243
DOI: 10.3168/jds.2022-23051 -
Journal of Fungi (Basel, Switzerland) Aug 2023Native wild yeasts from forest ecosystems represent an interesting potential source of biocontrol organisms in synergy with disease-tolerant forest materials. Yeasts...
Native wild yeasts from forest ecosystems represent an interesting potential source of biocontrol organisms in synergy with disease-tolerant forest materials. Yeasts have a combination of competitive mechanisms and low requirements for their biotechnological application as biocontrol agents. The current study aimed to increase the number of biocontrol candidates against and . The enzymatic and antagonistic activities of the biocontrol candidates were evaluated using different screening methods, in which the direct impact on the growth of the pathogen was measured as well as some properties such as cellulose and lignin degradation, tolerance to biocides, volatile compound production, or iron effect, which may be of interest in biotechnological processes related to the management of forest diseases. A total of 58 yeast strains belonging to 21 different species were obtained from oak forest and vineyard ecosystems and evaluated. The application of yeast treatment behaved differently depending on the pathogen and the plant clone. The 2g isolate () showed the highest inhibitory activity for and 25q and 90q () for . Clones IN416 and IN216 were the most susceptible and the most tolerant to , respectively, while the opposite was observed for .
PubMed: 37623611
DOI: 10.3390/jof9080840 -
International Journal of Food... Nov 2023Progress in oenological biotechnology now makes it possible to control alcoholic (AF) and malolactic (MLF) fermentation processes for the production of wines. Key...
Comparative study of inoculation strategies of Torulaspora delbrueckii and Saccharomyces cerevisiae on the performance of alcoholic and malolactic fermentations in an optimized synthetic grape must.
Progress in oenological biotechnology now makes it possible to control alcoholic (AF) and malolactic (MLF) fermentation processes for the production of wines. Key factors in controlling these processes and enhancing wine quality include the use of selected strains of non-Saccharomyces species, Saccharomyces cerevisiae, and Oenococcus oeni, as well as the method of inoculation (co-inoculation or sequential) and the timing of inoculation. In the present work, we investigated the effects of different inoculation strategies of two Torulaspora delbrueckii (Td-V and Td-P) strains followed by S. cerevisiae. Times (two, four, and six days) and types (co-inoculation and sequential) of inoculation were evaluated on the AF of a synthetic grape must. Furthermore, this synthetic medium was optimized by adding linoleic acid and β-sitosterol to simulate the natural grape must and facilitate reproducible results in potential assays. Subsequently, the wines obtained were inoculated with two strains of Oenococcus oeni to carry out MLF. Parameters after AF were analysed to observe the impact of wine composition on the MLF performance. The results showed that the optimization of the must through the addition of linoleic acid and β-sitosterol significantly enhanced MLF performance. This suggests that these lipids can positively impact the metabolism of O. oeni, leading to improved MLF efficiency. Furthermore, we observed that a 4-day contact period with T. delbrueckii leads to the most efficient MLF process and contributed to the modification of certain AF metabolites, such as the reduction of ethanol and acetic acid, as well as an increase in available nitrogen. The combination of Td-P with Oo-VP41 for 4 or 6 days during MLF showed that it could be the optimal option in terms of efficiency. By evaluating different T. delbrueckii inoculation strategies, optimizing the synthetic medium and studying the effects on wine composition, we aimed to gain insights into the relationship between AF conditions and subsequent MLF performance. Through this study, we aim to provide valuable insights for winemakers and researchers in the field of wine production and will contribute to a better understanding of the complex interactions between these species in the fermentation process.
Topics: Vitis; Fermentation; Saccharomyces cerevisiae; Torulaspora; Linoleic Acid; Culture Media
PubMed: 37597274
DOI: 10.1016/j.ijfoodmicro.2023.110367 -
Foods (Basel, Switzerland) Jul 2023has attracted renewed interest in recent years, for its biotechnological potential linked to its ability to enhance the flavor and aroma complexity of wine. Sequential...
has attracted renewed interest in recent years, for its biotechnological potential linked to its ability to enhance the flavor and aroma complexity of wine. Sequential fermentations with a selected native strain of (DiSVA 130) and low-sulfite native strain of (DiSVA 709) were carried out to establish their contribution in biocontrol and the aroma profile. A first set of trials were conducted to evaluate the effect of the sulfur dioxide addition on pure and / sequential fermentations. A second set of sequential fermentations without SO addition were conducted to evaluate the biocontrol and aromatic effectiveness of . Native showed a biocontrol action in the first two days of fermentation (wild yeasts reduced by c.a. 1 log at the second day). Finally, trials with the combination of both native and commercial / led to distinctive aromatic profiles of wines, with a significant enhancement in isoamyl acetate, phenyl ethyl acetate, supported by positive appreciations from the tasters, for ripe and tropical fruits, citrus, and balance. The whole results indicate that native could be a potential biocontrol tool against wild yeasts in the first phase of fermentation, contributing to improving the final wine aroma.
PubMed: 37569169
DOI: 10.3390/foods12152899 -
Food Microbiology Oct 2023Considering the growing interest in non-Saccharomyces wine yeasts, and notably in the context of mixed fermentations with S. cerevisiae, understanding their nutritional...
Considering the growing interest in non-Saccharomyces wine yeasts, and notably in the context of mixed fermentations with S. cerevisiae, understanding their nutritional behaviors is essential to ensure better management of these fermentations. The vitaminic consumption of three non-Saccharomyces yeasts (Starmerella bacillaris, Metschnikowia pulcherrima and Torulaspora delbrueckii) was investigated during their growth in wine-like conditions, providing initial evidence that they consume different vitamers. The vitamin consumption profiles during their growth highlighted releases of certain vitamers by the yeasts before re-assimilation, strongly suggesting the existence of synthesis pathways. Not only did the essential character of vitamin B1, in particular, appear to be a trait common to these yeasts, since all its vitamers are consumed, this investigation also provided evidence of the existence of species-dependent preferences for their vitaminic sources. These different behaviors were quite striking in certain vitamers, as was observed in nicotinamide: while it was consumed by T. delbrueckii, it was left untouched by S. bacillaris and produced by M. pulcherrima during growth. Furthermore, this offers grounds for further investigation into these yeasts' requirements, and provides the first tool for managing vitamin resources during mixed fermentations with S. cerevisiae, and for preventing nutritive deficiencies from occurring.
PubMed: 37567637
DOI: 10.1016/j.fm.2023.104332 -
Food Chemistry Jan 2024In this work, three mannoprotein extracts were obtained from T. delbrueckii by enzymatic and chemical treatments. The obtained mannoprotein extracts showed important...
In this work, three mannoprotein extracts were obtained from T. delbrueckii by enzymatic and chemical treatments. The obtained mannoprotein extracts showed important differences in their molecular weight distribution and monosaccharide composition, although no significant differences were found in their protein content. In order to evaluate the possible influence of mannoprotein characteristics in the interaction with flavanols, mannoprotein-flavanol interactions were studied by HPLC-DAD-MS and ITC. The results obtained indicate that the mannoprotein extracts were able to precipitate flavanols to a different extent. Furthermore, the degree of flavanol precipitation seemed not to be related to the affinity of the interaction but to the type of intermolecular forces. In this sense, a higher proportion of hydrogen bonding could favor a greater crosslinking between aggregates promoting flavanol precipitation. This, in turn, could be related to the MP characteristics since the presence of β-glucan moieties might have an effect on the formation of hydrogen bonds.
Topics: Torulaspora; Wine; Polyphenols; Plant Extracts; Fermentation
PubMed: 37536068
DOI: 10.1016/j.foodchem.2023.137044 -
Antioxidants (Basel, Switzerland) Jul 2023The resurgence of mead, a honey-based fermented beverage, is attributed to the increasing consumption of fermented foods and beverages, driven by its distinct flavors...
The resurgence of mead, a honey-based fermented beverage, is attributed to the increasing consumption of fermented foods and beverages, driven by its distinct flavors and perceived health benefits. This study investigates the influence of different yeast strains, namely var. , and , on the volatile and phenolic compounds of these beverages. Analytical techniques, including HPLC-DAD and GS/MS, were employed to analyze the chemical composition of the beverages. ANOVA analysis of variance was conducted to assess differences in the volatile and phenolic compounds. The findings reveal that yeast selection significantly impacts the chemical profiles of the beverages. fermentation preserves rosehip-specific flavonoids and phenolic acids. Sequential fermentation with demonstrated proficiency in generating esters, contributing to fruity and floral aromas in the beverages. This study investigates the importance of yeast selection in shaping the chemical composition of rosehip mead, providing insights into the distinct characteristics conferred by different yeast strains. By optimizing yeast selection and fermentation techniques, the overall quality and diversity of these beverages can be enhanced.
PubMed: 37507995
DOI: 10.3390/antiox12071457 -
International Journal of Food... Nov 2023Bioprotection by yeast addition is increasingly used in oenology as an alternative to sulfur dioxide (SO). Recent studies have also shown that it is likely to consume...
Bioprotection by yeast addition is increasingly used in oenology as an alternative to sulfur dioxide (SO). Recent studies have also shown that it is likely to consume dissolved O. This ability could limit O for other microorganisms and the early oxidation of the grape must. However, the ability of yeasts to consume O in a context of bioprotection was poorly studied so far considering the high genetic diversity of non-Saccharomyces. The first aim of the present study was to perform an O consumption rate (OCR) screening of strains from a large multi species collection found in oenology. The results demonstrate significant inter and intra species diversity with regard to O consumption. In the must M. pulcherrima consumes O faster than Saccharomyces cerevisiae and then other studied non-Saccharomyces species. The O consumption was also evaluate in the context of a yeast mix used as industrial bioprotection (Metschnikowia pulcherrima and Torulaspora delbrueckii) in red must. These non-Saccharomyces yeasts were then showed to limit the growth of acetic acid bacteria, with a bioprotective effect comparable to that of the addition of sulfur dioxide. Laboratory experiment confirmed the negative impact of the non-Saccharomyces yeasts on Gluconobacter oxydans that may be related to O consumption. This study sheds new lights on the use of bioprotection as an alternative to SO and suggest the possibility to use O consumption measurements as a new criteria for non-Saccharomyces strain selection in a context of bioprotection application for the wine industry.
Topics: Saccharomyces cerevisiae; Acetic Acid; Sulfur Dioxide; Wine; Fermentation; Yeasts; Vitis; Bacteria
PubMed: 37506548
DOI: 10.1016/j.ijfoodmicro.2023.110338 -
FEMS Yeast Research Jan 2023Lager yeasts are hybrids between Saccharomyces cerevisiae and S. eubayanus. Wine yeast biodiversity, however, has only recently been discovered to include besides pure...
Lager yeasts are hybrids between Saccharomyces cerevisiae and S. eubayanus. Wine yeast biodiversity, however, has only recently been discovered to include besides pure S. cerevisiae strains also hybrids between different Saccharomyces yeasts as well as introgressions from non-Saccharomyces species. Here, we analysed the genome of the Champagne Epernay Geisenheim (CEG) wine yeast. This yeast is an allotetraploid (4n - 1) hybrid of S. cerevisiae harbouring a substantially reduced S. kudriavzevii genome contributing only 1/3 of a full genome equivalent. We identified a novel oligopeptide transporter gene, FOT4, in CEG located on chromosome XVI. FOT genes were originally derived from Torulaspora microellipsoides and FOT4 arose by non-allelic recombination between adjacent FOT1 and FOT2 genes. Fermentations of CEG in Riesling and Müller-Thurgau musts were compared with the S. cerevisiae Geisenheim wine yeast GHM, which does not carry FOT genes. At low temperature (10°C), CEG completed fermentations faster and produced increased levels of higher alcohols (e.g. isoamyl alcohol). At higher temperature (18°C), CEG produced higher amounts of the pineapple-like alkyl esters i-butyric and propionic acid ethyl esters compared to GHM. The hybrid nature of CEG thus provides advantages in grape must fermentations over S. cerevisiae wine yeasts, especially with regard to aroma production.
Topics: Saccharomyces cerevisiae; Wine; Vitis; Cold Temperature; Fermentation; Esters
PubMed: 37500257
DOI: 10.1093/femsyr/foad033 -
International Journal of Molecular... Jul 2023Hybrid formation and introgressions had a profound impact on fermentative yeasts domesticated for beer, wine and cider fermentations. Here we provide a comparative...
Hybrid formation and introgressions had a profound impact on fermentative yeasts domesticated for beer, wine and cider fermentations. Here we provide a comparative genomic analysis of a British cider yeast isolate (E1) and characterize its fermentation properties. E1 has a genome into which ~102 kb of DNA were introgressed that replaced the endogenous homologous 55 genes of chromosome XIV between and . Sequence analyses indicated that the DNA donor was either a lager yeast or a yet unidentified ancestor. Interestingly, a second introgression event added ~66 kb of DNA from to the left telomere of . This region bears high similarity with the previously described region C introgression in the wine yeast EC1118. Within this region and encode two oligopeptide transporters that promote improved nitrogen uptake from grape must in E1, as was reported for EC1118. Comparative laboratory scale grape must fermentations between the E1 and EC1118 indicated beneficial traits of faster consumption of total sugars and higher glycerol production but low acetic acid and reduced ethanol content. Importantly, the cider yeast strain produced high levels of fruity ester, including phenylethyl and isoamyl acetate.
Topics: Saccharomyces cerevisiae; Wine; Alcoholic Beverages; Fermentation; Beer; Vitis
PubMed: 37446410
DOI: 10.3390/ijms241311232