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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 Research International (Ottawa,... Oct 2023In this study, Pichia kluyveri (P. kluyveri) and Lactobacillus plantarum (L. plantarum) were sequentially inoculated into a plant-based beverage consisting of bananas,...
In this study, Pichia kluyveri (P. kluyveri) and Lactobacillus plantarum (L. plantarum) were sequentially inoculated into a plant-based beverage consisting of bananas, broccoli, and wolfberries. The physicochemical characteristics, functional components, and taste of it at different stages were determined. After 8-d fermentation, the viable counts of P. kluyveri and L. plantarum were 6.50 log CFU/mL and 8.43 log CFU/mL, respectively. The ethanol was <0.5 % (v/v). Compared with control group, the superoxide dismutase (SOD) activity increased by 96.08 folds and total phenolics content increased by 1.09 folds. The contents of lactic acid, protocatechuic acid, and chlorogenic acid exhibited an upgrade trend, whereas the contents of caffeic acid and malic acid presented a downward tendency. Some organic acids had positive correlations with sensory quality, especially sourness. In addition, the γ-amino butyric acid (GABA) concentration and antioxidant activity were also improved during fermentation. Results showed the nutritional functional properties and sensory quality of this beverage could be improved through co-fermentation of P. kluyveri and L. plantarum.
Topics: Lactobacillus plantarum; Fermentation; Fermented Beverages; Pichia
PubMed: 37689854
DOI: 10.1016/j.foodres.2023.113060 -
Frontiers in Microbiology 2023The organoleptic profile and quality of wine are affected by the presence of different non-s species and strains. Therefore, the identification and characterization of...
The organoleptic profile and quality of wine are affected by the presence of different non-s species and strains. Therefore, the identification and characterization of non-s yeasts are the first step to understand their function, and to develop a better strain selection program for winemaking. This study investigated the biodiversity of non- yeasts associated with spontaneous fermentation of Cabernet Sauvignon wines from five sub-regions (Shi Zuishan, Yinchuan, Yu Quanying, Qing Tongxia and Hong Sibu) in Ningxia, China. Yeast species were identified by sequencing the 26S rRNA D1/D2 region, and strains at the subspecies level were discriminated using tandem repeat-tRNA (TRtRNA) PCR analysis. A total of 524 yeast colonies were isolated, and 19 non- yeast species belonging to 10 genera were identified, including , , sp., , , , , , sp., , , , , , , and . , , and were the three most dominated species, while other non- species were only present in the early stage of spontaneous fermentations at different levels. Further, for the yeast discrimination at strain level, 34 profiles were obtained by amplification with primer pairs TtRNASC/5CAG, while 40 profiles were obtained with primer pairs TtRNASC/ISSR-MB. This study explored the diversity of non- species in Ningxia, China, and made an important contribution of genetic resources for further strain development.
PubMed: 37664125
DOI: 10.3389/fmicb.2023.1253969 -
Letters in Applied Microbiology Sep 2023Film-forming yeasts are potential sources of defects in alcoholic beverages. The aim of this study is to assess the growth capacity of Pichia and Candida film-forming...
Film-forming yeasts are potential sources of defects in alcoholic beverages. The aim of this study is to assess the growth capacity of Pichia and Candida film-forming yeasts in cider and wine and the effects on their chemical composition. Cider, partially and fully fermented wine were inoculated with strains of C. californica, P. fermentans, P. kluyveri, P. kudriavzevii, P. manshurica, and P. membranifaciens to simulate a post-fermentative contamination. The former three species grew only in cider. Pichia manshurica and P. kudriavzevii displayed high viability in wine up to 13.18% (v v-1) ethanol. Significant changes in odour-active molecules from different chemical groups were observed in cider and wine in the inoculated samples, compared to the non-inoculated ones. Cider is more susceptible to contamination by all of the species tested, due to its low alcohol content, while P. membranifaciens, P. manshurica, and P. kudriavzevii are additionally potential spoilage agents of wine. This study highlights the risk of cider and wine contamination by film-forming yeasts. Their impact on aroma profiles depends on their ability to grow and their metabolism. This study contributes to an understanding of the possible physiological and metabolic mechanisms responsible for film formation and chemical changes in alcoholic beverages.
Topics: Wine; Fermentation; Pichia; Alcoholic Beverages; Candida
PubMed: 37656878
DOI: 10.1093/lambio/ovad099 -
Data in Brief Aug 2023strain APC 11.10 B was isolated from apple bark in Switzerland and exhibited strong antagonistic activity against plant pathogenic fungi (e.g., or isolates). In...
strain APC 11.10 B was isolated from apple bark in Switzerland and exhibited strong antagonistic activity against plant pathogenic fungi (e.g., or isolates). In order to identify the mechanisms underlying this antagonism, we have sequenced the genome of this isolate by long- and short-read sequencing technologies. The sequence data were assembled into nine scaffolds and a fully resolved circularized mitogenome. The total genome size was 10.9 Mbp and 7451 potential open reading frames (ORFs) and 202 tRNA genes were predicted. In comparison to two genomes deposited at the NCBI (of strains X31-10 and CBA6002), the APC 11.10 B strain seemed to represent a hybrid because backmapping of sequencing reads resulted in a high rate of heterozygous and structural variants in the nuclear genome (this was not observed for the mitochondrial genome). The (APC 11.10 B) draft genome represents a first step and resource for genome mining, comparative and functional genomics (e.g., identifying the biocontrol mode of action), and evolutionary studies. Since the genus comprises many biotechnologically relevant yeasts, the genome data may be used in a variety of fields and disciplines.
PubMed: 37496519
DOI: 10.1016/j.dib.2023.109394 -
Microorganisms Apr 2023Drinking wine is a processed beverage that offers high nutritional and health benefits. It is produced from grape must, which undergoes fermentation by yeasts (and... (Review)
Review
Drinking wine is a processed beverage that offers high nutritional and health benefits. It is produced from grape must, which undergoes fermentation by yeasts (and sometimes lactic acid bacteria) to create a product that is highly appreciated by consumers worldwide. However, if only one type of yeast, specifically , was used in the fermentation process, the resulting wine would lack aroma and flavor and may be rejected by consumers. To produce wine with a desirable taste and aroma, non- yeasts are necessary. These yeasts contribute volatile aromatic compounds that significantly impact the wine's final taste. They promote the release of primary aromatic compounds through a sequential hydrolysis mechanism involving several glycosidases unique to these yeasts. This review will discuss the unique characteristics of these yeasts (, , , , , , , , and others) and their impact on wine fermentations and co-fermentations. Their existence and the metabolites they produce enhance the complexity of wine flavor, resulting in a more enjoyable drinking experience.
PubMed: 37317152
DOI: 10.3390/microorganisms11051178 -
Food Research International (Ottawa,... Aug 2023In this study we investigated the yeast population present on partially dehydrated Nebbiolo grapes destined for 'Sforzato di Valtellina', with the aim to select...
In this study we investigated the yeast population present on partially dehydrated Nebbiolo grapes destined for 'Sforzato di Valtellina', with the aim to select indigenous starters suitable for the production of this wine. Yeasts were enumerated, isolated, and identified by molecular methods (5.8S-ITS-RFLP and D1/D2 domain sequencing). A genetic, physiological (ethanol and sulphur dioxide tolerance, potentially useful enzymatic activities, hydrogen sulphide production, adhesive properties, and killer activity) and oenological (laboratory pure micro-fermentations) characterization was also carried out. Based on relevant physiological features, seven non-Saccharomyces strains were chosen for laboratory-scale fermentations, either in pure or in mixed-culture (simultaneous and sequential inoculum) with a commercial Saccharomyces cerevisiae strain. Finally, the best couples and inoculation strategy were further tested in mixed fermentations in winery. In both laboratory and winery, microbiological and chemical analyses were conducted during fermentation. The most abundant species on grapes were Hanseniaspora uvarum (27.4 % of the isolates), followed by Metschnikowia spp. (21.0 %) and Starmerella bacillaris (12.9 %). Technological characterization highlighted several inter- and intra-species differences. The best oenological aptitude was highlighted for species Starm. bacillaris, Metschnikowia spp., Pichia kluyveri and Zygosaccharomyces bailli. The best fermentation performances in laboratory-scale fermentations were found for Starm. bacillaris and P. kluyveri, due to their ability to reduce ethanol (-0.34 % v/v) and enhance glycerol production (+0.46 g/L). This behavior was further confirmed in winery. Results of this study contribute to the knowledge of yeast communities associated with a specific environment, like those of Valtellina wine region.
Topics: Saccharomyces cerevisiae; Vitis; Wine; Fermentation; Yeast, Dried; Metschnikowia
PubMed: 37316074
DOI: 10.1016/j.foodres.2023.113005 -
Molecules (Basel, Switzerland) May 2023The market of non-alcoholic and low-alcohol beer has grown continuously thanks to the advocacy for healthy and responsible drinking. Non-alcoholic and low-alcohol...
The market of non-alcoholic and low-alcohol beer has grown continuously thanks to the advocacy for healthy and responsible drinking. Non-alcoholic and low-alcohol products usually possess less higher alcohols and acetates and more aldehyde off-flavors due to the manufacturing processes. The employment of non-conventional yeasts partially mitigates this problem. In this study, we used proteases to optimize the wort amino acid profile for better aroma production during yeast fermentation. The design of experiments was applied to increase the leucine molar fraction, aiming to boost 3-methylbutan-1-ol and 3-methylbutyl acetate (banana-like aromas). This led to an increase from 7% to 11% leucine in wort after protease treatment. The aroma output in the subsequent fermentation, however, was yeast-dependent. An 87% increase of 3-methylbutan-1-ol and a 64% increase of 3-methylbutyl acetate were observed when was used. When was employed, higher alcohols and esters from valine and isoleucine were increased: 58% more of 2-methylpropyl acetate, 67% more of 2-methylbutan-1-ol, and 24% more of 2-methylbutyl acetate were observed. Conversely, 3-methylbutan-1-ol decreased by 58% and 3-methylbutyl acetate largely remained the same. Apart from these, the amounts of aldehyde intermediates were increased to a varying extent. The impact of such increases in aromas and off-flavors on the perception of low-alcohol beer remains to be evaluated by sensory analysis in future studies.
Topics: Alcohols; Beer; Leucine; Peptide Hydrolases; Yeasts; Fermentation; Endopeptidases; Aldehydes; Acetates
PubMed: 37298894
DOI: 10.3390/molecules28114419 -
Journal of Water and Health May 2023Cockroaches are known as mechanical vectors of some pathogens that can infect humans. The present study aims to rapidly identify Periplaneta americana fungal pathogens...
Cockroaches are known as mechanical vectors of some pathogens that can infect humans. The present study aims to rapidly identify Periplaneta americana fungal pathogens from sewer systems of public hospitals in Esfahan using the polymerase chain reaction (PCR) technique. A total of 55 P. americana cockroaches were randomly collected by direct trapping from sewer systems of seven hospitals and screened for fungal infectious agents using standard morphological methods and the PCR sequencing. From the American cockroach, we isolated 62 yeasts and 31 molds from the surface, hemocoel, and digestive tract of P. americana. Based on DNA sequence comparisons and other taxonomic characteristics, they were identified as more than four species of yeast and four species of mold. Yeast species including Pichia kudriavzevii, Candida glabrata, Pichia kluyveri, and Candida viswanathii, and molds such as Aspergillus niger, Penicillium italicum, Mucor plumbeus, and Rhizopus oryzae were isolated repeatedly from the surface, hemocoel, and digestive tract of P. americana. Our results show that the use of a combination of morphological, molecular techniques, and phylogenetic analysis can lead to the identification of pathogenic fungal agents in American cockroaches and also knowledge of fungal pathogens-arthropod host relationships.
Topics: Animals; Humans; Cockroaches; Periplaneta; Phylogeny; Fungi; Hospitals
PubMed: 37254911
DOI: 10.2166/wh.2023.015 -
Foods (Basel, Switzerland) May 2023Traditional kombucha is a functional tea-based drink that has gained attention as a low or non-alcoholic beverage. The fermentation is conducted by a community of...
Traditional kombucha is a functional tea-based drink that has gained attention as a low or non-alcoholic beverage. The fermentation is conducted by a community of different microorganisms, collectively called SCOBY (Symbiotic Culture of Bacteria and Yeast) and typically consists of different acetic acid bacteria and fermenting yeast, and in some cases lactic acid bacteria that would convert the sugars into organic acids-mostly acetic acid. In this study, the effect of including a starter culture in a kombucha fermentation was investigated. additions led to a quicker accumulation of acetic acid along with the production of several acetate esters including isoamyl acetate and 2-phenethyl acetate. A subsequent tasting also noted a significant increase in the fruitiness of the kombucha. The significant contribution to the aroma content shows the promise of this yeast in future microbial formulations for kombucha fermentations.
PubMed: 37238757
DOI: 10.3390/foods12101938