Search Results (3,292)

Indigenous Mexican fermented beverages, such as pulque, colonche, tepache, and water kefir, are pillars of the country’s cultural and gastronomic heritage. Their sensory attributes and health-promoting properties arise from complex microbial consortia, in which lactic acid bacteria (LAB), mainly Lactobacillus and Leuconostoc, acetic acid bacteria (AAB), primarily Acetobacter, and yeasts such as Saccharomyces and Candida interact and secrete exopolysaccharides (EPSs). Dextran, levan, and heteropolysaccharides rich in glucose, galactose, and rhamnose have been consistently isolated from these beverages. EPSs produced by LAB enhance the viscosity and mouthfeel, extend the shelf life, and exhibit prebiotic, antioxidant, and immunomodulatory activities that support gut and immune health. Beyond food, certain EPSs promote plant growth, function as biocontrol agents against phytopathogens, and facilitate biofilm-based bioremediation, underscoring their biotechnological potential. This review integrates recent advances in the composition, biosynthetic pathways, and functional properties of microbial EPSs from Mexican fermented beverages. We compare reported titers, outline key enzymes, including dextransucrase, levansucrase, and glycosyltransferases, and examine how fermentation variables (the substrate, pH, and temperature) influence the polymer yield and structure. Finally, we highlight emerging applications that position these naturally occurring biopolymers as sustainable ingredients for food and agricultural innovation. Full article

Spirulina’s (Arthrospira platensis) use in food applications is limited by its dark color and sulfurous odor. This study aimed to develop a preharvest bioprocessing strategy using Saccharomyces cerevisiae co-cultivation to address these limitations. At a yeast/microalgae biomass ratio of 10:1000 with 5 g/L of glucose supplementation, co-cultivation for 24 h induced a rapid color transition from dark blue–green to light green and imparted “floral–fruity” aromas. Major bioactive compounds, including β-carotene, linoleic acid, and γ-linolenic acid, increased significantly, while volatile sulfur compounds were eliminated. Chlorophyll a and carotenoid contents rose by over two fold, reflecting enhanced photosynthetic efficiency. Mechanistic analyses revealed that yeast-derived acetic acid upregulated genes involved in flavor precursor biosynthesis and promoted biomass accumulation. This strategy integrates sensory improvement with nutritional enhancement, providing a sustainable approach for developing spirulina-based functional foods. Full article

Glucosamine (GlcN) is a high-value compound with significant health applications. GlcN is widely used in the food and health industry as a food additive or functional food. The development of a green, efficient, and safe method for GlcN production is of great significance due to the complexity of traditional production methods, environmental pollution, and sensitization of raw materials. In this study, Saccharomyces cerevisiae genes PFK1, PDB1, GNA1, ISR1, and PCM1 were knocked out using the Clustered Regularly Interspaced Short Palindromic Repeats Cas9 (CRISPR-Cas9) method. In addition, three key enzyme genes, glucosamine-6-phosphate deaminase GlmD, glucosamine-6-phosphate phosphatase GlmP, and ammonium transporter AMT1, were introduced to construct engineered strains for GlcN synthesis in the presence of high-concentration inorganic ammonium ions. The results indicated that S. cerevisiae HPG5 with GlmD, GlmP, and AMT1 integration and simultaneous deletion of PFK1, PDB1, GNA1, PCM1, and ISR1 achieved the highest GlcN yield (1.95 ± 0.02 g/L) during fermentation with 10 g/L (NH₄)₂SO₄, which was 2.47-fold higher than the control. The conversion rate of glucose to GlcN in HPG5 was 9.75% in liquid YPD medium containing 20 g/L of glucose and 10 g/L of (NH₄)₂SO₄. Thus, the results indicated that S. cerevisiae HPG5 could effectively produce GlcN in the presence of high-concentration ammonium sulphate. This study provides a promising alternative, S. cerevisiae HPG5, for GlcN production. Full article

The most notable effects of climate change on wine production are higher alcohol levels, lower acidity and changes to the regions suitable for growing grapes. One solution to acidity problems is the use of Lachancea thermotolerans, a yeast that produces lactic acid during fermentation, albeit at the cost of reduced aromatic complexity. A novel approach to addressing this problem is to use L. thermotolerans to produce wines with a very high acidity, regardless of other parameters, for subsequent blending with a control wine with a naturally low acidity. This achieves a balanced acidity while retaining the organoleptic characteristics of the control wine. This is a novel idea, as L. thermotolerans is not usually used in the final wine. However, the objective from the beginning is to create a blend that combines the best characteristics of the control wine with the improved acidity provided by L. thermotolerans. Base wines were produced by inoculating Saccharomyces cerevisiae 20, 40, or 60 h after inoculating L. thermotolerans. Base wines generally show an increase in lactic acid content and a decrease in certain key aromatic compounds, such as isoamyl acetate, 2-phenylethyl acetate, ethyl hexanoate, and ethyl octanoate. Concentrations of other compounds such as acetaldehyde and higher alcohols also increase. The base wines were then blended with a low-acidity control wine. The resulting blends exhibited higher acidity than the control wine, as well as better aromatic profiles, particularly regarding fruity and green fruit aromatic compounds, compared to base wines. Ten volatile compounds have been correlated with lactic acid production by L. thermotolerans, namely ethyl hexanoate; ethyl butanoate; 2-methylbutanol; ethyl heptanoate; isoamyl acetate; acetaldehyde; isobutanol; 2-phenylethanol; dodecanol; and acetoin. The first five are negatively correlated and the rest are positively correlated. Lastly, sensory analysis revealed that the blends achieved the best balance between acidity and aroma, making them the most popular with tasters. Full article

Microbial fuel cells (MFCs) are one of the contributors to the novel sustainable energy generation from organic waste. However, the application of MFCs is limited due to the slow charge transfer between cells and electrodes. This problem can be solved by modifying cells with conductive polymers, such as polypyrrole (PPy). We investigated the viability and electroactivity of modified cells at five different pyrrole concentrations, namely 8, 25, 50, 100, and 200 mM. The 100 mM concentration of PPy solution had the highest impact on yeast cells’ proliferation and growth, with the CFU/mL of PPy-treated yeast cells being 0.6 × 10⁷ ± 5 × 10⁻². The power density of the constructed MFC was evaluated by using an external load. The MFCs were analyzed using cyclic voltammetry (CV) and differential pulse voltammetry (DPV). Although CV results with different pyrrole concentrations were similar, DPV indicated that yeast modification with 50 mM pyrrole resulted in the most significant current density, which may be attributed to an increase in charge transfer due to the conductive properties of polypyrrole. The power density achieved with modified yeast in wastewater, 12 mW/m², reached levels similar to those in laboratory solutions, 45 mW/m². Full article

Background/Objectives: Glucan particles (GPs), derived from Saccharomyces cerevisiae yeast, possess unique biomedical properties. Nevertheless, it is imperative that a comprehensive risk assessment is conducted during pre-clinical development. GPs are primarily constituted of a naturally occurring polymer known as β-glucan. This study characterized GPs, focusing on physicochemical attributes, biocompatibility, and immunomodulatory potential. Methods: GPs were characterized for size, morphology, surface charge, and protein encapsulation efficiency using dynamic light scattering (DLS), electron microscopy, and encapsulation assays. Biocompatibility was assessed through cytotoxicity assays (MTT), hemolysis tests, and measurement of reactive oxygen (ROS) and nitric oxide (NO) production in immune cells. Immunomodulatory potential was evaluated by cytokine and chemokine secretion analysis in peripheral blood mononuclear cells (PBMCs) and monocyte-derived dendritic cells (moDCs) and through in vivo immunization studies in a murine model, focusing on cellular immune responses. Results: GPs demonstrated stable physicochemical properties and efficient protein encapsulation, highlighting their suitability as vaccine delivery systems. They exhibited biocompatibility by not inducing cytotoxicity, hemolysis, or excessive ROS and NO production. In PBMCs, GPs stimulated cytokine secretion, suggesting their adjuvant potential. GPs were efficiently internalized by monocytes and led to specific chemokine secretion in stimulated moDCs. In a murine model, GPs induced distinctive cellular immune responses, including TNF-α and IFN-γ production and effector memory T cell activation. Conclusions: These findings emphasize GPs’ biocompatibility and immunomodulatory effects, highlighting their potential in immunotherapy and vaccine development, particularly for targeting infectious agents like hepatitis B virus. Full article

In this study, persimmons, which are rich in various nutrients and bioactive compounds, were used as the raw material for wine production. Persimmon wine was produced by inoculating with Saccharomyces cerevisiae and fermenting the mixture at 30 °C for seven days. During this process, we analyzed changes in physicochemical properties, organic acids, free sugars, ethanol, methanol, free amino acids, total phenolic content (TPC), total flavonoid content (TFC), and antioxidant activities. Over the seven-day fermentation period, soluble solids decreased from 16.27 °Brix to 5.57 °Brix, pH declined from 5.93 to 4.90, and total acidity increased from 0.12% to 0.41%. Succinic, lactic, and acetic acids were identified as major organic acids, while glucose and fructose were depleted after six days of fermentation. The ethanol concentration reached 7.93% on day seven, while methanol increased to 0.050%. The free amino acid content decreased as fermentation progressed. The TPC and TFC increased significantly. Antioxidant capacity increased, as observed from DPPH, ABTS, and FRAP assay results. These results suggest that alcohol fermentation of raw persimmons induces significant changes in key quality-related components and enhances antioxidant activity. Overall, the findings provide valuable foundational data supporting the industrial application of persimmon wine. Full article

This study investigates the Enzyme Biofilm Method (EBM), a biological wastewater treatment technology previously developed by the authors. EBM employs microbial-derived hydrolytic enzyme groups in the initial treatment stage to break down high-molecular-weight organic matter—such as starch, proteins, and fats—into low-molecular-weight compounds. These compounds enhance the growth of native microorganisms, promoting biofilm formation on carriers and improving treatment efficiency. Over the past decade, EBM has been practically applied in food factory wastewater facilities handling high organic loads. The enzyme groups used in EBM are derived from cultures of Bacillus mojavensis, Saccharomyces cariocanus, and Lacticaseibacillus paracasei. To clarify the system’s mechanism and ensure its practical viability, this study focused on starch—a prevalent and recalcitrant component of food wastewater—using two evaluation approaches. Verification 1: Field testing at a starch factory showed that adding enzyme groups to the equalization tank effectively reduced biological oxygen demand (BOD) through starch degradation. Verification 2: Laboratory experiments confirmed that the enzyme groups possess both amylase and maltase activities, sequentially breaking down starch into glucose. The resulting glucose supports microbial growth, facilitating biofilm formation and BOD reduction. These findings confirm EBM’s potential as a sustainable and effective solution for treating high-strength food industry wastewater. Full article

Although beer fermentation has traditionally been carried out with Saccharomyces, the boom in craft brewing has led to the use of non-conventional yeast species for beer production. This group also includes non-Saccharomyces starters, which are commonly used in winemaking and which have different technological characteristics compared to standard representatives of the Saccharomyces genus. One of the important characteristics of the non-Saccharomyces group is the richer enzyme profile, which leads to the production of beverages with different taste and aroma profiles. The aim of this study was to investigate sweet and hopped wort fermentation with seven strains of active dry non-conventional yeasts of Lachancea spp., Metschnikowia spp., Torulaspora spp. and a mixed culture of Saccharomyces cerevisiae and Torulaspora delbrueckii. One ale and one lager active dry yeast strain were used as control strains. The extract consumption, ethanol production, degree of fermentation, pH drop, as well as the yeast secondary metabolites formed by the yeast (higher alcohols, esters and aldehydes) in sweet and hopped wort were investigated. The results indicated that all of the studied types of non-conventional yeasts have serious potential for use in beer production in order to obtain new beer styles. For the purposes of this study, statistical methods, principle component analysis (PCA) and correlation analysis were used, thus establishing the difference in the fermentation kinetics of the growth in the studied species in sweet and hopped wort. It was found that hopping had a significant influence on the fermentation kinetics of some of the species, which was probably due to the inhibitory effect of the iso-alpha-acids of hops. Directions for future research with the studied yeast species in beer production are presented. Full article

Objectives: Saccharomyces boulardii CNCM I-745, a probiotic yeast, is effectively used for the treatment of acute diarrhea as well as for the prevention and treatment of traveller‘s diarrhea and diarrhea under tube feeding. The underlying mechanisms are not fully elucidated. Both antitoxic and regulatory effects on the intestinal barrier, mediated either by the yeast or yeast-derived substrates, have been discussed. Methods: To examine the effects of Saccharomyces boulardii released substrates (S.b.S) on gastrointestinal (GI) barrier function, a murine small intestinal organoid cell model under stress was used. Stress was induced by lipopolysaccharide (LPS) exposure or withdrawal of growth factors from cell culture medium (GF_Red). Stressed organoids were treated with S.b.S (200 µg/mL), and markers of GI barrier and inflammatory response were assessed. Results: GF_Red-induced stress was characterized by disturbances in selected tight junction (TJ) (p < 0.05), adherent junction (AJ) (p < 0.001), and mucin (Muc) formation (p < 0.01), measured by gene expressions, whereby additional S.b.S treatment was found to reverse these effects by increasing Muc2 (from 0.22 to 0.97-fold change, p < 0.05), Occludin (Ocln) (from 0.37 to 3.5-fold change, p < 0.0001), and Claudin (Cldn)7 expression (from 0.13 ± 0.066-fold change, p < 0.05) and by decreasing Muc1, Cldn2, Cldn5, and junctional adhesion molecule A (JAM-A) expression (all p < 0.01). Further, S.b.S normalized expression of nucleotide binding oligomerization domain (Nod)2- (from 44.5 to 0.51, p < 0.0001) and matrix metalloproteinase (Mmp)7-dependent activation (from 28.3 to 0.02875 ± 0.0044 ** p < 0.01) of antimicrobial peptide defense and reduced the expression of several inflammatory markers, such as myeloid differentiation primary response 88 (Myd88) (p < 0.01), tumor necrosis factor α (Tnfα) (p < 0.01), interleukin (IL)-6 (p < 0.01), and IL-1β (p < 0.001). Conclusions: Our data provide new insights into the molecular mechanisms by which Saccharomyces boulardii CNCM I-745-derived secretome attenuates inflammatory responses and restores GI barrier function in small intestinal organoids. Full article

This study was undertaken to identify foodborne bacteria and fungi from different parts of eggs depending on their storage duration, organoleptic properties, total viable count, and antibiotic resistance profile. Thirty-two samples were randomly collected from commercial layer farms in Mymensingh. Following the protocol of sample preparation, outer-surface and inner-content samples were streaked onto various selective media. Isolation and identification were carried out by observing Gram staining and biochemical properties. Molecular detection was confirmed through a PCR assay using specific primers for Salmonella spp., E. coli, Staphylococcus spp., and fungus (Simplicillium spp. and Saccharomyces spp.). To determine the antibiotic resistance profile, the disk diffusion method was followed against nine antibiotic disks. The isolation rate of E. coli, Salmonella spp., and Staphylococcus spp. was 53.13%, 40.63%, and 40.63%, respectively, in the outer eggshell and 15.63%, 25%, and 15.63%, respectively, in the inner content of the eggs. Regarding the fungus content (yeast and mold), 100% was obtained in the outer eggshell, whereas there was an absence of fungus in the inner content. It was observed that all the isolates of E. coli, Salmonella spp., and Staphylococcus spp. were highly sensitive to either Ciprofloxacin or Levofloxacin and extremely resistant to Amoxicillin or Azithromycin drug disks or both. The data also shows that storage duration had a proportional relationship with TVC and an inversely proportional relationship with organoleptic properties. This study indicates that eggs harbor multidrug-resistant foodborne bacteria, which might constitute a public health hazard if these antibiotic-resistant bacteria are transferred to humans. Full article

Rose hips are rich in polyphenols, making them a promising ingredient for the development of functional fruit-based beverages. This study aimed to evaluate the effect of Pulsed Electric Field (PEF) extraction treatment on rose hip (RH) pulp to enhance the extraction of polyphenols, carotenoids, and volatile compounds. Additionally, this study examined the impact of adding rose hip berries during different stages of carbohydrate fermentation on the resulting phenolic and aroma profiles. A control wort and four experimental formulations were prepared. Rose hip pulp—treated or untreated with PEF—was added either during fermentation or beforehand, and the volatiles produced were analyzed using GC-MS (in triplicate). Fermentation was carried out over 10 days at 20 °C using Saccharomyces cerevisiae and Torulaspora delbrueckii. At a 10:1 ratio, all beverage samples were subjected to physicochemical testing and HPLC analysis for polyphenols, organic acids, and carotenoids, as well as GC-MS analysis for aroma compounds. The results demonstrated that the use of PEF-treated rose hips significantly improved phenolic compound extraction. Moreover, the PEF treatment enhanced the aroma profile of the beverage, contributing to a more complex and appealing sensory experience. This research highlights the rich polyphenol content of rose hips and the potential of PEF-treated fruit as a natural ingredient to improve both the functional and sensory qualities of fruit-based beverages. Their application opens new possibilities for the development of innovative, health-promoting drinks in the brewing industry. Full article

Diacylglycerol-O-acyltransferase 1 (DGAT1, EC 2.3.1.20) is a pivotal enzyme in plant triacylglycerol (TAG) biosynthesis. Previous work identified conserved di-arginine (R) motifs (R-R, R-X-R, and R-X-X-R) in its N-terminal cytoplasmic acyl-CoA binding domain. To elucidate their functional significance, we engineered R-rich sequences in the N-termini of Tropaeolum majus and Zea mays DGAT1s. Comparative analysis with their respective non-mutant constructs showed that deleting or substituting R with glycine in the N-terminal region of DGAT1 markedly reduced lipid accumulation in both Camelina sativa seeds and Saccharomyces cerevisiae cells. Immunofluorescence imaging revealed co-localization of non-mutant and R-substituted DGAT1 with lipid droplets (LDs). However, disruption of an N-terminal di-R motif destabilizes DGAT1, alters LD organization, and impairs recombinant oleosin retention on LDs. Further evidence suggests that the di-R motif mediates DGAT1 retrieval from LDs to the endoplasmic reticulum (ER), implicating its role in dynamic LD–ER protein trafficking. These findings establish the conserved di-R motifs as important regulators of DGAT1 function and LD dynamics, offering insights for the engineering of oil content in diverse biological systems. Full article

Background: Biostimulants naturally improve plant growth, stress tolerance, and nutrient use efficiency and activate defenses by increasing protective metabolites (phenols, anthocyanins) in grapes. In viticulture, especially when using inactive yeasts, they modulate genetic expression and improve the skin resistance, color, and aroma profile of wine grapes in line with sustainable practices. Methods: Two wine grape cultivars, Merlot and Cabernet Sauvignon, were sprayed with the inactive yeast Saccharomyces cerevisiae in a single treatment in pre-veraison or in a double treatment in pre-veraison and veraison. Berry weight, must, total polyphenols, anthocyanins, and mechanical and colorimetric properties were measured on fresh grapes. Results: Two-way ANOVA revealed that titratable acidity (TA), pH, and total polyphenol content (TPC) were not affected, while mean berry weight and anthocyanin content varied by cultivar, treatment, and interaction; total soluble solids (TSS) differed only by cultivar. Inactive yeasts reduced weight in the single-treatment thesis but stabilized it in the double-treatment one; anthocyanins decreased in Cabernet Sauvignon but increased in Merlot. Mechanical and colorimetric analyses showed cultivar-dependent responses, with significant improvements in elasticity, skin thickness, and hue of berries, especially in Merlot when the treatment was applied twice. Conclusions: Inactive yeasts (IYs) showed an effect on the weight of the berries, the anthocyanins, the mechanics, and the color; Merlot significantly improved skin thickness, elasticity, and hue; and Cabernet remained less reactive to treatments. Full article

Thermovinification has emerged as a rising alternative method in red wine production, gaining popularity among winemakers. The use of autochthonous yeasts isolated from grapes is also an interesting practice that contributes to the creation of wine with a distinctive regional character. This research investigated how combining thermovinification with autochthonous yeast strains influences the fermentation dynamics of Syrah wine. Six treatments were conducted, combining the use of commercial and two autochthonous yeasts with traditional vinification (7-day maceration) and thermovinification (65 °C for 2 h) processes. Sugars and alcohols were quantified during alcoholic fermentation by high-performance liquid chromatography with refractive index detection. Cell viability and kinetic parameters, such as ethanol formation rate and sugar consumption, were also evaluated. The Syrah wine’s composition was characterized by classical wine analyses (OIV procedures). The results showed that cell viability was unaffected by thermovinification. Thermovinification associated with autochthonous yeasts improved the efficiency of alcoholic fermentation. Thermovinified wines also yielded a higher alcohol content (13.9%). Future studies should investigate how thermovinification associated with autochthonous yeasts affects the metabolomic and flavoromic properties of Syrah wine and product acceptability. Full article