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Foods (Basel, Switzerland) Sep 2023One approach towards maintaining healthy microbiota in the human gastrointestinal tract is through the consumption of probiotics. Until now, the majority of probiotic...
One approach towards maintaining healthy microbiota in the human gastrointestinal tract is through the consumption of probiotics. Until now, the majority of probiotic research has focused on probiotic bacteria, but over the last few years more and more studies have demonstrated the probiotic properties of yeast, and also of species besides the well-studied var. . Probiotic strains have to present the ability to survive in harsh conditions of the host body, like the digestive tract. Must fermentation might be an example of a similar harsh environment. In the presented study, we examined the probiotic potential of 44 yeast strains isolated from Polish wines. The tested isolates belonged to six species: and . The tested strains were subjected to an assessment of probiotic properties, their safety and their other properties, such as enzymatic activity or antioxidant properties, in order to assess their potential usefulness as probiotic yeast candidates. Within the most promising strains were representatives of three species: , and . strains 15 and 16, as well as strain 37, showed, among other features, survivability in gastrointestinal tract conditions exceeding 100%, high hydrophobicity and autoaggregation, had no hemolytic activity and did not produce biogenic amines. The obtained results show that Polish wines might be a source of potential probiotic yeast candidates with perspectives for further research.
PubMed: 37761101
DOI: 10.3390/foods12183392 -
Food Science and Biotechnology Jan 2024Biogenic amines are produced during fermentation and can act as harmful substances. Strains related to the fermentation of extract were identified and and were...
UNLABELLED
Biogenic amines are produced during fermentation and can act as harmful substances. Strains related to the fermentation of extract were identified and and were selected to investigate the relationship between biogenic amines and precursors, NaCl or ethanol. Biogenic amines were analyzed by high-performance liquid chromatography. Among precursors added, arginine was most effective for the biogenic amines formation. After 24 h incubation, the content of total biogenic amines increased from 37.60 to 51.75 mL/L for and from 2.60 to 33.30 mL/L for in arginine-added medium. The number of yeast decreased in both NaCl- and ethanol-YM broth added with arginine, but there was no correlation between the number of yeast and biogenic amines. These results suggested that the formation of biogenic amines by yeast was affected by various factors and their interactions rather than a single factor, such as decarboxylase activity and stress factor.
SUPPLEMENTARY INFORMATION
The online version contains supplementary material available at 10.1007/s10068-023-01328-8.
PubMed: 38186610
DOI: 10.1007/s10068-023-01328-8 -
Applied and Environmental Microbiology Jan 2016Microbial starter cultures have extensively been used to enhance the consistency and efficiency of industrial fermentations. Despite the advantages of such controlled...
Microbial starter cultures have extensively been used to enhance the consistency and efficiency of industrial fermentations. Despite the advantages of such controlled fermentations, the fermentation involved in the production of chocolate is still a spontaneous process that relies on the natural microbiota at cocoa farms. However, recent studies indicate that certain thermotolerant Saccharomyces cerevisiae cultures can be used as starter cultures for cocoa pulp fermentation. In this study, we investigate the potential of specifically developed starter cultures to modulate chocolate aroma. Specifically, we developed several new S. cerevisiae hybrids that combine thermotolerance and efficient cocoa pulp fermentation with a high production of volatile flavor-active esters. In addition, we investigated the potential of two strains of two non-Saccharomyces species that produce very large amounts of fruity esters (Pichia kluyveri and Cyberlindnera fabianii) to modulate chocolate aroma. Gas chromatography-mass spectrometry (GC-MS) analysis of the cocoa liquor revealed an increased concentration of various flavor-active esters and a decrease in spoilage-related off-flavors in batches inoculated with S. cerevisiae starter cultures and, to a lesser extent, in batches inoculated with P. kluyveri and Cyb. fabianii. Additionally, GC-MS analysis of chocolate samples revealed that while most short-chain esters evaporated during conching, longer and more-fat-soluble ethyl and acetate esters, such as ethyl octanoate, phenylethyl acetate, ethyl phenylacetate, ethyl decanoate, and ethyl dodecanoate, remained almost unaffected. Sensory analysis by an expert panel confirmed significant differences in the aromas of chocolates produced with different starter cultures. Together, these results show that the selection of different yeast cultures opens novel avenues for modulating chocolate flavor.
Topics: Acetates; Cacao; Esters; Fermentation; Flavoring Agents; Hot Temperature; Humans; Saccharomyces cerevisiae; Taste
PubMed: 26590272
DOI: 10.1128/AEM.02556-15 -
Journal of Applied Microbiology Feb 2018The purpose of this study was to evaluate the effect of warehouse storage conditions on the composition of the fungal community of green coffee beans (GCB) that were...
AIMS
The purpose of this study was to evaluate the effect of warehouse storage conditions on the composition of the fungal community of green coffee beans (GCB) that were stored in jute sacks for 1 year.
METHODS AND RESULTS
Molecular characterization of the fungal community composition and population dynamics obtained by Q-PCR, CE-SSCP (Simpson's diversity index D) and Illumina MiSeq sequencing indicated that Saccharomycetales dominated during the first 6 months of storage period with species as Meyerozyma guilliermondii and Pichia kluyveri. However, after 6 months of storage, the filamentous genus Wallemia became dominant. Principal components analysis correlated this fungal dynamic with storage conditions and other variables as chromaticity (colour), water activity, moisture content, reducing sugars concentration, fungal infection and ochratoxin A production.
CONCLUSIONS
This study demonstrated that GCB stored in jute sacks after 6 months of storage lead to fungal population dynamics, decreased chromaticity in GCB by bleaching and, then, affected overall quality.
SIGNIFICANCE AND IMPACT OF THE STUDY
Storage plays an important role in the quality evolution during the handling of the GCB. In this context, the composition of the microbial community could be considered a marker to assess the trade value of the coffee beans.
Topics: Biodiversity; Coffea; Food Storage; Fungi; Ochratoxins; Seeds
PubMed: 29215772
DOI: 10.1111/jam.13656 -
Microorganisms Jun 2019The goal of this study is to assess to what extent non- yeasts can introduce aromatic changes of industrial interest in fermentative, varietal and aged aromas of wine....
The goal of this study is to assess to what extent non- yeasts can introduce aromatic changes of industrial interest in fermentative, varietal and aged aromas of wine. Aroma precursors from Riesling and Garnacha grapes were extracted and used in two independent sequential experiments. Synthetic musts were inoculated, either with (Sc) or with (Pk), (Td) or (Lt), followed by Sc. The fermented samples were subjected to anoxic aging at 50 °C for 0, 1, 2 or 5 weeks before an aroma analysis. The fermentative aroma profiles were consistently changed by non-: all strains induced smaller levels of isoamyl alcohol; Pk produced huge levels of aromatic acetates and can induce high levels of fatty acids (FA) and their ethyl esters (EE); Td produced large levels of branched acids and of their EE after aging, and induced smaller levels of FA and their EE; Lt produced reduced levels of FA and their EE. The varietal aroma was also deeply affected: TDN (1,1,6-trimethyl-1,2- dihydronaphthalene) levels in aged wines were reduced by Pk and enhanced by Lt in Garnacha; the levels of vinylphenols can be much reduced, particularly by Lt and Pk. TD and Lt can increase linalool and geraniol in young, but not in aged wines.
PubMed: 31174281
DOI: 10.3390/microorganisms7060164 -
Yeast (Chichester, England) Oct 2018Antagonistic yeasts suppress plant pathogenic fungi by various mechanisms, but their biocontrol efficacy also depends on the ability to compete and persist in the...
Antagonistic yeasts suppress plant pathogenic fungi by various mechanisms, but their biocontrol efficacy also depends on the ability to compete and persist in the environment. The goal of the work presented here was to quantify the composition of synthetic yeast communities in order to determine the competitiveness of different species and identify promising candidates for plant protection. For this purpose, colony counting of distinct species and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS; MALDI biotyping) were used to distinguish different yeast species and to quantify the composition of a synthetic community of six yeasts (Aureobasidium pullulans, Candida subhashii, Cyberlindnera sargentensis, Hanseniaspora sp., Metschnikowia pulcherrima and Pichia kluyveri) over time, on apples and in soil, and in different growth media. These studies revealed important characteristics that predispose the different species for particular applications. For example, the competitiveness and antagonistic activity of C. subhashii was strongly increased in the presence of N-acetylglucosamin as the sole carbon source, M. pulcherrima and A. pullulans were the strongest competitors on apple, and C. sargentensis competed the best in soil microcosms. Based on these laboratory studies, M. pulcherrima and A. pullulans are promising candidates for biocontrol applications against fungal phyllosphere diseases, while C. sargentensis may hold potential for use against soilborne fungal pathogens. These results document the potential of MALDI-TOF MS for the quantitative analysis of synthetic yeast communities and highlight the value of studying microorganisms with relevant functions in moderately complex, synthetic communities and natural substrates rather than as individual isolates.
Topics: Antibiosis; Biological Control Agents; Candida; Culture Media; Malus; Microbial Consortia; Pichia; Saccharomyces cerevisiae; Soil Microbiology; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Yeasts
PubMed: 29752875
DOI: 10.1002/yea.3321 -
AMB Express Dec 2021In total, 16 yeast were isolated from Chinese strong flavour Daqu samples and underwent RAPD analysis and identification. Totally, 11 different species were identified...
In total, 16 yeast were isolated from Chinese strong flavour Daqu samples and underwent RAPD analysis and identification. Totally, 11 different species were identified among these isolates including Saccharomyces cerevisiae, Hanseniaspora vineae, Pichia kluyveri, Trichosporon asahii, Wickerhamomyces anomalus, Kluyveromyces lactis, Yarrowia lipolytica, Wickerhamomyces mori, Galactomyces geotrichum, Dabaryomyces hansenii, and Saccharomyces kudriavzevii. To understand the impact of these yeast strains on the quality and flavour of Daqu, we then assessed volatile compounds associated with Daqu samples fermented with corresponding strains. These analyses revealed strain YE006 exhibited the most robust ability to produce ethanol via fermentation but yielded relatively low quantities of volatile compounds, whereas strain YE010 exhibited relatively poor fermentation efficiency but produced the greatest quantity of volatile compounds. These two yeast strains were then utilized in a mixed culture to produce fortified Daqu, with the optimal inoculum size being assessed experimentally. These analyses revealed that maximal fermentation, saccharifying, liquefying, and esterifying power as well as high levels of volatile compounds were achieved when using a 2% inoculum composed of YE006/YE010 at a 1:2 (v/v) ratio. When the liquor prepared using this optimized fortified Daqu was compared to unfortified control Daqu, the former was found to exhibit significantly higher levels of flavour compounds and better sensory scores. Overall, our findings may provide a reliable approach to ensuring Daqu quality and improving the consistency and flavour of Chinese strong-flavour liquor through bioaugmentation.
PubMed: 34952959
DOI: 10.1186/s13568-021-01337-y -
Foods (Basel, Switzerland) Feb 2024Non-alcoholic beer (NAB) and low-alcoholic beer (LAB) are taking over the market with growing sales. Sustainable recycling and valorization of exhausted brewer's spent...
Non-alcoholic beer (NAB) and low-alcoholic beer (LAB) are taking over the market with growing sales. Sustainable recycling and valorization of exhausted brewer's spent grain (BSG) coming from craft beer is a relevant issue in the brewing process. In this work, recycled BSG and BSG + GJ (supplemented with 10% grape juice) were used as a wort substrate to inoculate , , and non-conventional yeasts to produce NABLAB craft beer. Results showed that wort composed of only recycled BSG produced appreciated NAB beers (ethanol concentration from 0.12% to 0.54% /), while the addition of 10% grape juice produced LAB beers (ethanol concentration from 0.82 to 1.66% /). As expected, volatile compound production was highest with the addition of grape juice. showed lactic acid production, characterizing both worts with the production of ethyl butyrate and isoamyl acetate. exhibited relevant amounts of hexanol, phenyl ethyl acetate and β-phenyl ethanol (BSG + GJ). and showed consistent volatile production, but only in BSG + GJ where fermentation activity was exhibited. The overall results indicated that reused BSGs, non-conventional yeasts and grape juice are suitable bioprocesses for specialty NABLAB beer.
PubMed: 38397482
DOI: 10.3390/foods13040505 -
Polish Journal of Microbiology Mar 2017Microbes have evolved ways of interference competition to gain advantage over their ecological competitors. The use of secreted antagonistic compounds by yeast cells is...
Microbes have evolved ways of interference competition to gain advantage over their ecological competitors. The use of secreted antagonistic compounds by yeast cells is one of the prominent examples. Although this killer behavior has been thoroughly studied in laboratory yeast strains, our knowledge of the antagonistic specificity of killer effects in nature remains limited. In this study, yeast strains were collected from various niches and screened for antagonistic activity against one toxin-sensitive strain of Saccharomyces cerevisiae and three pathogenic fungi. We demonstrate that some strains with antagonistic activity against these pathogenic fungi can be found in antagonist culture tests. These yeasts were identified as members of Trichosporon asahii, Candida stellimalicola, Wickerhamomyces anomalus, Ustilago esculenta, Aureobasidium pullulans, and Pichia kluyveri. The results indicated that the antagonistic activity of these killer yeasts has a narrow optimal pH range. Furthermore, we found that the antagonistic activity of some species is strain-dependent.
Topics: Antibiosis; Candida; Hydrogen-Ion Concentration; Pichia; Yeasts
PubMed: 29359688
DOI: 10.5604/17331331.1234997 -
Journal of Food Protection Oct 2006The potential use of the commercial biocontrol products Serenade (Bacillus subtilis QST-713) and Trichodex (Trichoderma harzianum Rifai strain T39) to inhibit the...
The potential use of the commercial biocontrol products Serenade (Bacillus subtilis QST-713) and Trichodex (Trichoderma harzianum Rifai strain T39) to inhibit the postharvest pathogenic molds Penicillium crustosum and Mucor circinelloides was investigated. Both products exhibited antagonistic activity in vitro against the pathogens, reducing their growth at different levels. In addition, epiphytic yeasts isolated from peaches were identified as Candida maltosa, Pichia fermentans, and Pichia kluyveri by PCR-restriction fragment length polymorphism of internal transcribed spacer regions and screened for antagonistic activity against the same molds. The efficacy of biocontrol in vitro was dependent on the concentration of the yeast cells. Optimal yeast concentrations were above 10(7) CFU ml(-1). However, C. maltosa and P. fermentans were more effective than P. kluyveri in inhibiting molds. The exclusion of antifungal metabolite production and direct competition for nutrients or space with the pathogens was proposed as the mechanism of biocontrol. Application of biocontrol agents directly on artificially wounded peach fruits significantly reduced the incidence of mold rot during storage at 20 degrees C.
Topics: Antibiosis; Bacillus subtilis; Colony Count, Microbial; DNA, Fungal; Food Preservation; Fungi; Humans; Mucor; Penicillium; Pest Control, Biological; Prunus; Species Specificity; Time Factors; Trichoderma; Yeasts
PubMed: 17066929
DOI: 10.4315/0362-028x-69.10.2465