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1.
Food Microbiol ; 120: 104479, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38431325

RESUMO

Saccharomyces pastorianus, hybrids of Saccharomyces cerevisiae and Saccharomyces eubayanus, were generally regarded as authentic lager beer yeasts. In recent years, with more new findings of other Saccharomyces genus hybrids, yeasts used in lager beer brewing have been proved much more complicated than previous cognition. In this study, we analyzed the different fermentation characteristics of 54 yeast strains used for lager brewing in normal and very high gravity brewing based on group classification. The difference between Group Ⅰ and Group Ⅱ lager yeasts were more striking in very high gravity brewing. However, during our research progress, we realized that some yeasts used in this study were actually hybrids of S. cerevisiae and Saccharomyces kudriavzevii. Features of these hybrids could be beneficial to very high gravity brewing. We further discussed about the mechanism behind their outstanding characteristics and the reason why group classification methods of lager beer yeasts had limitations. Hybridization in yeasts is constantly getting richer. Lager yeasts could have more possibilities based on better understandings of their genetic background and roles of other Saccharomyces genus hybrids. Their heterosis shed light on innovation in brewing and other diverse fermentation industries.


Assuntos
Saccharomyces cerevisiae , Saccharomyces , Saccharomyces cerevisiae/genética , Fermentação , Saccharomyces/genética , Cerveja
2.
Food Microbiol ; 120: 104463, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38431337

RESUMO

This study aimed to explore the non-volatile metabolomic variability of a large panel of strains (44) belonging to the Saccharomyces cerevisiae and Saccharomyces uvarum species in the context of the wine alcoholic fermentation. For the S. cerevisiae strains flor, fruit and wine strains isolated from different anthropic niches were compared. This phenotypic survey was achieved with a special focus on acidity management by using natural grape juices showing opposite level of acidity. A 1H NMR based metabolomics approach was developed for quantifying fifteen wine metabolites that showed important quantitative variability within the strains. Thanks to the robustness of the assay and the low amount of sample required, this tool is relevant for the analysis of the metabolomic profile of numerous wines. The S. cerevisiae and S. uvarum species displayed significant differences for malic, succinic, and pyruvic acids, as well as for glycerol and 2,3-butanediol production. As expected, S. uvarum showed weaker fermentation fitness but interesting acidifying properties. The three groups of S. cerevisiae strains showed different metabolic profiles mostly related to their production and consumption of organic acids. More specifically, flor yeast consumed more malic acid and produced more acetic acid than the other S. cerevisiae strains which was never reported before. These features might be linked to the ability of flor yeasts to shift their metabolism during wine oxidation.


Assuntos
Saccharomyces , Vitis , Vinho , Saccharomyces cerevisiae/metabolismo , Saccharomyces/genética , Vinho/análise , Vitis/metabolismo , Fermentação , Ácido Acético/metabolismo
3.
Molecules ; 29(5)2024 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-38474538

RESUMO

Non-Saccharomyces (NSc) yeasts have great potential in improving wine qualities. In this study, two NSc and two Saccharomyces cerevisiae (Sc) samples were tested on their performance of mono-inoculated and composite culture in the fermentation of Chunjian citrus wine. The cell count, Brix degree, total sugar, total acidity, alcohol level, pH value, color intensity (CI), and tonality were determined to evaluate the contribution of NSc to the quality of citrus wine in the mixed fermentation. Volatile compounds were analyzed by HS-SPME-GC-MS, and sensory evaluation was carried out. During the 9-day fermentation, the mixed-culture wine exhibited a higher cell concentration than the pure culture. After the fermentation, mixed-culture wine specifically decreased the concentrations of unfavorable volatile compounds, such as isobutanol and octanoic acid, and increased favorable volatile compounds, including ethyl octanoate, ethyl decanoate, and phenylethyl acetate. The quality category of the citrus wine was improved compared with the Sc mono-inoculated wines, mainly in regard to aroma, retention, and sweetness. The study shows that the mixed fermentation of NSc and Sc has positive impacts on reducing alcohol level and total acidity and increasing CI. The present work demonstrates that the mixed fermentation of NSc and Sc has enormous beneficial impacts on improving the quality of citrus wine.


Assuntos
Saccharomyces , Vinho , Saccharomyces cerevisiae , Vinho/análise , Fermentação , Etanol/análise
4.
Food Res Int ; 181: 114117, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38448112

RESUMO

The inoculation of S. cerevisiae can address the excessive acidity in Suanyu, but its influence on the microbial community structure has not been documented. In this study, the microbiota succession, and metabolites of Suanyu with the inoculation of acid-reducing S. cerevisiae L7 were explored. The findings revealed that the addition of S. cerevisiae L7 elevated the pH, and decreased the microbial α-diversity. In Suanyu, the dominant bacterial genera were Lactiplantibacillus and Bacillus, while the dominant fungal genera were Meyerozyma and Saccharomyces. Following the inoculation of S. cerevisiae L7, the relative abundance of Lactiplantibacillus decreased from 21 % to 13 %. Meanwhile, the growth of fungi such as Meyerozyma and Candida was suppressed. The rise in Saccharomyces had a significant impact on various pathways related to amino acid and carbohydrate metabolism, causing the accumulation of flavor compounds. This study sheds more lights on the methods for manipulating microbial community structure in fermented food.


Assuntos
Bacillus , Microbiota , Saccharomyces , Saccharomycetales , Saccharomyces cerevisiae , Aminoácidos
5.
Sci Rep ; 14(1): 4844, 2024 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-38418660

RESUMO

About half of the 1.62 billion cases of anemia are because of poor diet and iron deficiency. Currently, the use of iron-enriched yeasts can be used as the most effective and possible way to prevent and treat anemia due to the ability of biotransformation of mineral compounds into the organic form. In this research, for the first time, Saccharomyces (S.) boulardii was used for iron enrichment with the aim that the probiotic properties of yeast provide a potential iron supplement besides improving the bioavailability of iron. Also, due to its higher resistance than other Saccharomyces strains against stresses, it can protect iron against processing temperatures and stomach acidic-enzymatic conditions. So, the effect of three important variables, including concentration of iron, molasses and KH2PO4 on the growth and biotransformation of yeast was investigated by the Box-Behnken design (BBD). The best conditions occurred in 3 g/l KH2PO4, 20 g/l molasses and 12 mg/l FeSO4 with the highest biotransformation 27 mg Fe/g dry cell weight (DCW) and 6 g/l biomass weight. Such yeast can improve fermented products, provide potential supplement, and restore the lost iron of bread, which is a useful iron source, even for vegetarians-vegans and play an important role in manage with anemia. It is recommended that in future researches, attention should be paid to increasing the iron enrichment of yeast through permeabilizing the membrane and overcoming the structural barrier of the cell wall.


Assuntos
Anemia , Probióticos , Saccharomyces boulardii , Saccharomyces , Saccharomyces cerevisiae/metabolismo , Ferro/metabolismo , Saccharomyces/metabolismo , Probióticos/metabolismo
6.
PLoS One ; 19(2): e0296859, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38416719

RESUMO

To assess the possible impact of climatic variation on microbial community composition in organic winemaking, we employed a metabarcoding approach to scrutinize the microbiome in a commercial, organic, Pinot noir wine production system that utilizes autochthonous fermentation. We assessed microbial composition across two vintages (2018 and 2021) using biological replicates co-located at the same winery. Microbial dynamics were monitored over four important fermentation time points and correlated with contemporaneous climate data. Bacterial (RANOSIM = 0.4743, p = 0.0001) and fungal (RANOSIM = 0.4738, p = 0.0001) compositions were different in both vintages. For bacteria, Lactococcus dominated the diversity associated with the 2018 vintage, while Tatumella dominated the 2021 vintage. For fungal populations, while Saccharomyces were abundant in both vintages, key differences included Starmerella, copious in the 2018 vintage; and Metschnikowia, substantive in the 2021 vintage. Ordination plots correlated the climatic variables with microbial population differences, indicating temperature as a particularly important influence; humidity values also differed significantly between these vintages. Our data illustrates how climatic conditions may influence microbial diversity during winemaking, and further highlights the effect climate change could have on wine production.


Assuntos
Microbiota , Saccharomyces , Vitis , Vinho , Vinho/análise , Bactérias/genética , Fermentação , Vitis/microbiologia
7.
Int J Food Microbiol ; 412: 110566, 2024 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-38241754

RESUMO

Yeasts play a crucial role in transforming apple must into cider. While Saccharomyces cerevisiae (Sc) has been traditionally associated to cider fermentations worldwide, cryotolerant species such as Saccharomyces uvarum (Su) as well as natural S. cerevisiae × S. uvarum (Sc×Su) hybrids have also been detected in ciders fermented at low temperatures. This study aimed to evaluate the ability of two Patagonian cryotolerant yeast strains (Su and Se) and their interspecific hybrids with a Sc to conduct handcrafted apple must fermentations and a second fermentation process (champenoise method). The main chemical parameters and sensory quality of the resulting sparkling beverages was also analysed. Firstly, Sc×Se and Sc×Su hybrids were evaluated in their fermentative features at laboratory scale. Hybrids were compared with their respective parental species evidencing significant differences in the physicochemical and aromatic composition of the obtained base ciders. Both Su parental strain and the hybrid Sc×Se were selected for performing pilot scale fermentations (250 L) using natural (non-sterilized) apple juice at two different temperatures: 20 °C and 13 °C. Sc parental strain was also evaluated for comparative purposes. All base ciders obtained were then subjected to a second fermentation. A high implantation capacity of both Su and the hybrid was evidenced at the lowest evaluated temperature, while commercial Sc strain was not detected at the final fermentation stage, independently from the temperature. All sparkling ciders exhibited distinct physicochemical profiles. Ciders inoculated with commercial Sc (but effectively fermented with local Sc strains) allowed the development of malolactic fermentation (MLF) in processes carried out at both temperatures. Contrarily, no MLF was observed in ciders inoculated with either Su or the hybrid. Sparkling ciders fermented with Su displayed the highest concentrations of 2-phenylethanol and 2-phenylethyl acetate, regardless of the fermentation temperature. Conversely, ciders fermented with the hybrid at 20 °C exhibited the highest concentrations of ethyl octanoate and ethyl decanoate, contributing to floral and fruity notes in the beverage. Sensory analysis conducted with untrained individuals revealed a preference for sparkling ciders produced with the hybrid strain at both 20 °C and 13 °C. The cider fermented at 20 °C exhibited floral notes, sweetness, and a full body, while ciders fermented at 13 °C displayed moderate acidity and a well-balanced profile. Conversely, a trained panel described the cider fermented at 20 °C with Su as a fruity and acidic beverage, whereas the ciders fermented at 13 °C exhibited intense bitterness and acidity. This study highlights the potential of cryotolerant Saccharomyces species and hybrids in the development of new starter cultures for producing artisanal sparkling ciders with distinctive properties.


Assuntos
Malus , Saccharomyces , Humanos , Saccharomyces cerevisiae , Temperatura , Bebidas Alcoólicas/análise , Fermentação , Malus/química
8.
Genome Biol Evol ; 15(11)2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37972247

RESUMO

The Saccharomyces species have diverged in their thermal growth profile. Both Saccharomyces cerevisiae and Saccharomyces paradoxus grow at temperatures well above the maximum growth temperature of Saccharomyces kudriavzevii and Saccharomyces uvarum but grow more poorly at lower temperatures. In response to thermal shifts, organisms activate a stress response that includes heat shock proteins involved in protein homeostasis and acquisition of thermal tolerance. To determine whether Saccharomyces species have diverged in their response to temperature, we measured changes in gene expression in response to a 12 °C increase or decrease in temperature for four Saccharomyces species and their six pairwise hybrids. To ensure coverage of subtelomeric gene families, we sequenced, assembled, and annotated a complete S. uvarum genome. In response to heat, the cryophilic species showed a stronger stress response than the thermophilic species, and the hybrids showed a mixture of parental responses that depended on the time point. After an initial strong response indicative of high thermal stress, hybrids with a thermophilic parent resolved their heat shock response to become similar to their thermophilic parent. Within the hybrids, only a small number of temperature-responsive genes showed consistent differences between alleles from the thermophilic and cryophilic species. Our results show that divergence in the heat shock response is mainly a consequence of a strain's thermal tolerance, suggesting that cellular factors that signal heat stress or resolve heat-induced changes are relevant to thermal divergence in the Saccharomyces species.


Assuntos
Saccharomyces , Saccharomyces/genética , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Temperatura , Resposta ao Choque Térmico/genética , Proteínas de Choque Térmico/genética
10.
J Agric Food Chem ; 71(41): 15417-15428, 2023 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-37814909

RESUMO

Yeast flocculation and viability are critical factors in beer production. Adequate flocculation of yeast at the end of fermentation helps to reduce off-flavors and cell separation, while high viability is beneficial for yeast reuse. In this study, we used comparative genomics to analyze the genome information on Saccharomyces pastorianus W01, and its spontaneous mutant W02 with appropriate weakened flocculation ability (better off-flavor reduction performance) and unwanted decreased viability, to investigate the effect of different gene expressions on yeast flocculation or/and viability. Our results indicate that knockout of CNE1, CIN5, SIN3, HP-3, YPR170W-B, and SCEPF1_0274000100 and overexpression of CNE1 and ALD2 significantly decreased the flocculation ability of W01, while knockout of EPL1 increased the flocculation ability of W01. Meanwhile, knockout of CIN5, YPR170W-B, OST5, SFT1, SCEPF1_0274000100, and EPL1 and overexpression of SWC3, ALD2, and HP-2 decreased the viability of W01. CIN5, EPL1, SCEPF1_0274000100, ALD2, and YPR170W-B have all been shown to affect yeast flocculation ability and viability.


Assuntos
Saccharomyces cerevisiae , Saccharomyces , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Floculação , Saccharomyces/genética , Saccharomyces/metabolismo , Genômica , Cerveja/análise , Fermentação
11.
Food Microbiol ; 116: 104357, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37689417

RESUMO

Kombucha is a fermented beverage derived from a sweetened tea fermentation inoculated with a bacteria-yeast consortium referred to as Symbiotic Culture of Bacteria and Yeast (SCOBY). Different SCOBY cultures can impact the beverage's quality and make the whole process highly variable. Adding Saccharomyces yeast cultures to the fermentation process can avoid stalled fermentations, providing a reproducible beverage. Here, we explored using different Saccharomyces eubayanus strains together with SCOBY in the context of kombucha fermentation. Our results show that yeast x SCOBY co-cultures exhibited a robust fermentation profile, providing ethanol and acetic acid levels ranging from 0,18-1,81 %v/v and 0,35-1,15 g/L, respectively. The kombucha volatile compound profile of co-cultures was unique, where compounds such as Isopentyl acetate where only found in yeast x SCOBY fermentations. Metabarcoding revealed that the SCOBY composition was also dependent on the S. eubayanus genotype, where besides Saccharomyces, amplicon sequence variants belonging to Brettanomyces and Starmerella were detected. These differences concomitated global changes in transcript levels in S. eubayanus related to the metabolism of organic molecules used in kombucha fermentation. This study highlights the potential for exploring different S. eubayanus strains for kombucha fermentation, and the significant yeast genotype effect in the profile differentiation in this process.


Assuntos
Brettanomyces , Saccharomyces , Saccharomycetales , Fermentação , Saccharomyces/genética , Saccharomycetales/genética
12.
Food Microbiol ; 115: 104321, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37567631

RESUMO

Selection of the appropriate yeast strain is one of the most crucial steps in a brewery. Traditionally, yeast strain's abilities during beer fermentation are described according to brewer's experiences. Hence, these descriptions could be inaccurate and strictly based on sensory experiences. In this study, lager beers fermented by four traditional bottom-fermented yeast strains were characterized in detail by sensomic approach. The obtained results revealed that yeast strains can influence most of the sensory-related components in beer, not only esters and higher alcohols, but also carbonyls, amino acids, saccharides, fatty acids, heterocyclic compounds, hop oils, and other hop-related components. By comparison of chemical and sensory characteristics of each studied beer, the theoretical importance of sensory interactions on beer flavor perception was also revealed as the general conception that the beers with similar flavors have also similar chemical profiles (and vice versa) was seemed as not valid.


Assuntos
Saccharomyces cerevisiae , Saccharomyces , Saccharomyces cerevisiae/metabolismo , Cerveja/análise , Saccharomyces/metabolismo , Fermentação
13.
Sci Rep ; 13(1): 13026, 2023 08 10.
Artigo em Inglês | MEDLINE | ID: mdl-37563274

RESUMO

Nutritional yeast-produced soy yogurt has grown in demand, because of its unique nutritional and health benefits. It has low cholesterol, no lactose, and high levels of protein, probiotic yeast, vitamins, and minerals. In this work, Soymilk (12.5%) was prepared and fermented to produce soy yogurt. Growth curves, probiotic characteristics of Saccharomyces boulardii CNCMI-745 and Lactobacillus plantarum KU985432 were determined. The nutritional value of both yogurts was evaluated, including viable cell count, protein, vitamin B-complex, sugars, phenolic acids, and fatty acids, mineral content, stability, and storage. Analysis of the physicochemical composition of the yogurts included assessment of titratable acidity, antioxidant potential, viscosity, and moisture content. The probiotic viable count of the produced yogurts met the standards for commercial yogurts. S. boulardii CNCMI-745 displayed safety characteristics and high tolerance to heat, acid, and alkaline stress. The produced B vitamins increased in both yogurts. The total saturated fatty acids in Saccharomyces-yogurt decreased, while the unsaturated fatty acids increased. Saccharomyces-yogurt showed high antioxidant activity, phenolic acids, and crude protein content. Both yogurts demonstrated the same tendency for stability during 16 day-storage. In conclusion, using nutritional yeast in the production of soy yogurt increased its nutritional content more than probiotic lactic acid bacteria.


Assuntos
Lactobacillus plantarum , Probióticos , Saccharomyces boulardii , Saccharomyces , Leite de Soja , Lactobacillus plantarum/metabolismo , Iogurte/microbiologia , Probióticos/metabolismo , Leite de Soja/química , Saccharomyces cerevisiae , Antioxidantes/metabolismo , Minerais/metabolismo
14.
Microb Biotechnol ; 16(9): 1858-1871, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37449952

RESUMO

Erythritol is produced in yeasts via the reduction of erythrose into erythritol by erythrose reductases (ERs). However, the genes codifying for the ERs involved in this reaction have not been described in any Saccharomyces species yet. In our laboratory, we recently showed that, during alcoholic fermentation, erythritol is differentially produced by Saccharomyces cerevisiae and S. uvarum species, the latter being the largest producer. In this study, by using BLAST analysis and phylogenetic approaches the genes GRE3, GCY1, YPR1, ARA1 and YJR096W were identified as putative ERs in Saccharomyces cerevisiae Then, these genes were knocked out in our S. uvarum strain (BMV58) with higher erythritol biosynthesis compared to control S. cerevisiae wine strain, to evaluate their impact on erythritol synthesis and global metabolism. Among the mutants, the single deletion of GRE3 markedly impacts erythritol production, although ΔYPR1ΔGCY1ΔGRE3 was the combination that most decreased erythritol synthesis. Consistent with the increased production of fermentative by-products involved in redox balance in the Saccharomyces uvarum strain BMV58, erythritol synthesis increases at higher sugar concentrations, hinting it might be a response to osmotic stress. However, the expression of GRE3 in the S. uvarum strain was found to peak just before the start of the stationary phase, being consistent with the observation that erythritol increases at the start of the stationary phase, when there is low sugar in the medium and nitrogen sources are depleted. This suggests that GRE3 plays its primary function to help the yeast cells to maintain the redox balance during the last phases of fermentation.


Assuntos
Eritritol , Saccharomyces , Eritritol/metabolismo , Fermentação , Homeostase , Osmorregulação , Oxirredução , Filogenia , Saccharomyces/genética , Saccharomyces/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Açúcares/metabolismo , Aldeído Redutase/genética , Aldeído Redutase/metabolismo
15.
Biotechnol J ; 18(11): e2300240, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37522392

RESUMO

Ribonucleic acid (RNA) and its degradation products are important biomolecules widely used in the food and pharmaceutical industries for their flavoring and nutritional functions. In this study, we used a genome-scale metabolic network model (GSMM) to explore genetic targets for nucleic acid synthesis in a Saccharomyces pastorianus strain (G03). Yeast 8.5.0 was used as the base model, which accurately predicted G03's growth. Using OptForce, we found that overexpression of ARO8 and ATP1 among six different strategies increased the RNA content of G03 by 58.0% and 74.8%, respectively. We also identified new metabolic targets for improved RNA production using a modified GSMM called TissueModel, constructed using the GIMME transcriptome constraint tool to remove low-expressed reactions in the model. After running OptKnock, the RNA content of G03-△BNA1 and G03-△PMA1 increased by 44.6% and 39.8%, respectively, compared to G03. We suggest that ATP1, ARO8, BNA1, and PMA1 regulate cell fitness, which affects RNA content. This study is the first to identify strategies for RNA overproduction using GSMM and to report that regulation of ATP1, ARO8, BNA1, and PMA1 can increase RNA content in S. pastorianus. These findings also provide valuable knowledge on model reconstruction for S. pastorianus.


Assuntos
RNA , Saccharomyces , RNA/metabolismo , Genoma Fúngico/genética , Saccharomyces/genética , Saccharomyces/metabolismo , Saccharomyces cerevisiae/genética , Redes e Vias Metabólicas , Fermentação
16.
BMC Gastroenterol ; 23(1): 229, 2023 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-37400812

RESUMO

BACKGROUND: Probiotics are effective for treating acute infectious diarrhoea caused by bacteria, but there are inconsistent results for the effectiveness of probiotics for diarrhoea caused by viruses. In this article we want to determine whether Sb supplementation has an effect on acute inflammatory viral diarrhoea diagnosed with the multiplex panel PCR test. The aim of this study was to evaluate the efficacy of Saccharomyces boulardii (Sb) as a treatment in patients diagnosed with viral acute diarrhoea. METHODS: From February 2021 to December 2021, 46 patients with a confirmed diagnosis of viral acute diarrhoea diagnosed with the polymerase chain reaction multiplex assay were enrolled in a double-blind, randomized placebo-controlled trial. Patients received paracetamol 500 mg as a standard analgesic and 200 mg of Trimebutine as an antispasmodic treatment plus 600 mg of Sb (n = 23, 1 × 109/100 mL Colony forming unit) or a placebo (n = 23) orally once daily for eight days. The improvement in and severity of symptoms were measured using a symptom diary, the Patient Global Impression and the Patient Global Impression of Change scales (days 4 and 8), both answered and recorded by the patient. RESULTS: Of the 46 patients who completed treatment, 24 (52%) were men and 22 (48%) were women. The average age was 35.6 ± 12.28 years (range 18 to 61 years). The average duration of the evolution of illness at the time of diagnosis was 0.85 ± 0.73 days (maximum 2 days). On day 4 after the diagnosis, 20% reported pain and 2% reported fever, but on day 8, no patient reported pain or fever. On day 4, 70% of patients in the Sb group and 26% in the placebo group reported improvement (P = 0.03), based on the Patients' Global Impression of Change scale, which assesses patient's rating of overall improvement. These findings suggest that 3 to 4 days of treatment with Sb helped to improve symptoms of diarrhoea caused by a virus. CONCLUSION: Treatment with Sb on acute inflammatory diarrhoea of viral aetiology shows no changes regarding the severity of the symptoms; nevertheless, it seems to impact improvement positively. TRIAL REGISTRATION: 22CEI00320171130 dated on 16/12/2020, NCT05226052 dated on 07/02/2022.


Assuntos
Enterite , Probióticos , Saccharomyces boulardii , Saccharomyces , Masculino , Humanos , Adulto , Feminino , Adolescente , Adulto Jovem , Pessoa de Meia-Idade , Resultado do Tratamento , Saccharomyces cerevisiae , Diarreia/terapia , Diarreia/microbiologia , Probióticos/uso terapêutico , Método Duplo-Cego
18.
Microb Cell Fact ; 22(1): 109, 2023 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-37287064

RESUMO

The probiotic yeast Saccharomyces boulardii (Sb) is a promising chassis to deliver therapeutic proteins to the gut due to Sb's innate therapeutic properties, resistance to phage and antibiotics, and high protein secretion capacity. To maintain therapeutic efficacy in the context of challenges such as washout, low rates of diffusion, weak target binding, and/or high rates of proteolysis, it is desirable to engineer Sb strains with enhanced levels of protein secretion. In this work, we explored genetic modifications in both cis- (i.e. to the expression cassette of the secreted protein) and trans- (i.e. to the Sb genome) that enhance Sb's ability to secrete proteins, taking a Clostridioides difficile Toxin A neutralizing peptide (NPA) as our model therapeutic. First, by modulating the copy number of the NPA expression cassette, we found NPA concentrations in the supernatant could be varied by sixfold (76-458 mg/L) in microbioreactor fermentations. In the context of high NPA copy number, we found a previously-developed collection of native and synthetic secretion signals could further tune NPA secretion between 121 and 463 mg/L. Then, guided by prior knowledge of S. cerevisiae's secretion mechanisms, we generated a library of homozygous single gene deletion strains, the most productive of which achieved 2297 mg/L secretory production of NPA. We then expanded on this library by performing combinatorial gene deletions, supplemented by proteomics experiments. We ultimately constructed a quadruple protease-deficient Sb strain that produces 5045 mg/L secretory NPA, an improvement of > tenfold over wild-type Sb. Overall, this work systematically explores a broad collection of engineering strategies to improve protein secretion in Sb and highlights the ability of proteomics to highlight under-explored mediators of this process. In doing so, we created a set of probiotic strains that are capable of delivering a wide range of protein titers and therefore furthers the ability of Sb to deliver therapeutics to the gut and other settings to which it is adapted.


Assuntos
Probióticos , Saccharomyces boulardii , Saccharomyces , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Saccharomyces boulardii/genética , Saccharomyces boulardii/metabolismo , Saccharomyces/genética , Saccharomyces/metabolismo , Probióticos/metabolismo , Endopeptidases/metabolismo
19.
BMC Biol ; 21(1): 102, 2023 05 08.
Artigo em Inglês | MEDLINE | ID: mdl-37158891

RESUMO

BACKGROUND: Horizontal gene transfer (HGT) is an evolutionary mechanism of adaptive importance, which has been deeply studied in wine S. cerevisiae strains, where those acquired genes conferred improved traits related to both transport and metabolism of the nutrients present in the grape must. However, little is known about HGT events that occurred in wild Saccharomyces yeasts and how they determine their phenotypes. RESULTS: Through a comparative genomic approach among Saccharomyces species, we detected a subtelomeric segment present in the S. uvarum, S. kudriavzevii, and S. eubayanus species, belonging to the first species to diverge in the Saccharomyces genus, but absent in the other Saccharomyces species. The segment contains three genes, two of which were characterized, named DGD1 and DGD2. DGD1 encodes dialkylglicine decarboxylase, whose specific substrate is the non-proteinogenic amino acid 2-aminoisobutyric acid (AIB), a rare amino acid present in some antimicrobial peptides of fungal origin. DGD2 encodes putative zinc finger transcription factor, which is essential to induce the AIB-dependent expression of DGD1. Phylogenetic analysis showed that DGD1 and DGD2 are closely related to two adjacent genes present in Zygosaccharomyces. CONCLUSIONS: The presented results show evidence of an early HGT event conferring new traits to the ancestor of the Saccharomyces genus that could be lost in the evolutionary more recent Saccharomyces species, perhaps due to loss of function during the colonization of new habitats.


Assuntos
Saccharomyces , Transaminases , Saccharomyces/genética , Transferência Genética Horizontal , Filogenia , Saccharomyces cerevisiae , Aminoácidos , Ácidos Aminoisobutíricos
20.
Appl Microbiol Biotechnol ; 107(14): 4409-4427, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37233754

RESUMO

Many microorganisms are capable of developing biofilms under adverse conditions usually related to nutrient limitation. They are complex structures in which cells (in many cases of different species) are embedded in the material that they secrete, the extracellular matrix (ECM), which is composed of proteins, carbohydrates, lipids, and nucleic acids. The ECM has several functions including adhesion, cellular communication, nutrient distribution, and increased community resistance, this being the main drawback when these microorganisms are pathogenic. However, these structures have also proven useful in many biotechnological applications. Until now, the most interest shown in these regards has focused on bacterial biofilms, and the literature describing yeast biofilms is scarce, except for pathological strains. Oceans and other saline reservoirs are full of microorganisms adapted to extreme conditions, and the discovery and knowledge of their properties can be very interesting to explore new uses. Halotolerant and osmotolerant biofilm-forming yeasts have been employed for many years in the food and wine industry, with very few applications in other areas. The experience gained in bioremediation, food production and biocatalysis with bacterial biofilms can be inspiring to find new uses for halotolerant yeast biofilms. In this review, we focus on the biofilms formed by halotolerant and osmotolerant yeasts such as those belonging to Candida, Saccharomyces flor yeasts, Schwannyomyces or Debaryomyces, and their actual or potential biotechnological applications. KEY POINTS: • Biofilm formation by halotolerant and osmotolerant yeasts is reviewed. • Yeasts biofilms have been widely used in food and wine production. • The use of bacterial biofilms in bioremediation can be expanded to halotolerant yeast counterparts.


Assuntos
Saccharomyces , Vinho , Saccharomyces cerevisiae , Leveduras , Candida , Vinho/microbiologia , Biofilmes
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