Search Results (3,602)

Rose hip processing generates seed-rich by-products that remain underexplored beyond oil extraction, despite their potential as a source of phenolic compounds and antioxidant activity. This study investigates the effect of bioprocessing (short-term fermentation) on the phenolic composition and antioxidant activity of rose hip (Rosa spp.) seed by-products, with relevance to cosmetic-oriented applications related to oxidative stress modulation. Rose hip seeds were obtained after juice production and subjected to short-term fermentation (14 days at 21 °C) using Saccharomyces cerevisiae, followed by mechanical separation and drying. Non-fermented and bioprocessed seeds were analyzed for individual phenolic compounds and antioxidant activity (DPPH, ABTS, FRAP), and correlation and multivariate analyses were conducted. Bioprocessing reduced total identified phenolics from 15.79 to 10.72 mg/g DW (≈32%), primarily due to a decrease in epigallocatechin (10.89 to 6.50 mg/g DW). In parallel, the relative contribution of phenolic acids increased, including gallic acid (0.50 to 0.60 mg/g DW) and salicylic acid (0.98 to 1.20 mg/g DW), indicating a selective compositional redistribution accompanied by partial degradation. Antioxidant activity decreased after bioprocessing (DPPH ~340 to ~250 µmol TE/g DW) but remained substantial. Correlation analysis identified epigallocatechin as the main contributor to antioxidant capacity. These findings show that rose hip seeds behave as a process-sensitive phenolic matrix in which bioprocessing alters the balance of individual compounds without complete loss of antioxidant activity. The results indicate that seed-derived by-products retain functional potential for further valorization in cosmetic-oriented applications. Full article

The transition towards a circular bioeconomy is essential to mitigate the environmental pressures caused by the increasing global demand for food and energy. Agro-food waste (AFW) is a plentiful, inexpensive feedstock, exploitable in biorefineries to produce valuable molecules. The aim of this study was to isolate native non-conventional yeasts (NCY) from various AFW and to evaluate their potential for the ‘natural’ synthesis of aroma compounds via fermentation. Ten strains were isolated and identified as belonging to Saccharomyces cerevisiae, Pichia kluyveri, Pichia californica and Wickerhamomyces anomalus species. The fermentative performance and production of aroma volatile compounds were tested using different household wastes as substrates. Figs containing substrate, which is the richest in fermentable sugars, allowed for the fastest microbial adaptation and highest yields of volatile compounds. HS-SPME-GC/MS analysis revealed that the most prominent compounds were isoamyl alcohol, ethyl acetate and isoamyl acetate with the highest production levels showed by W. anomalus YDSCYP4 and P. kluyveri YDSCYP5. Enzymatic profiling revealed significant arylamidase and esterase activities in the selected strains, related to their role in the hydrolysis of aroma precursors. These findings demonstrate the efficiency of these autochthonous yeasts for the sustainable production of aroma compounds, supporting the development of eco-friendly biotechnological processes. Full article

Deoxynivalenol (DON), a Group III carcinogenic mycotoxin frequently detected in cereals and animal-derived food products, poses serious health risks to animals and humans. In this study, we developed a genetically engineered Saccharomyces cerevisiae strain as a proof-of-concept platform for DON detoxification. The yeast was engineered to co-express two detoxification genes, YTDepA and YTDepB (homologs of DepA and DepB from Devosia mutans 17-2-E-8) originally identified in Youhaiella tibetensis. Concurrently, the pyrroloquinoline quinone (PQQ) biosynthesis gene cluster from Klebsiella pneumoniae was integrated to supply the essential cofactor. Gene expression was verified by qRT-PCR and Western blot. The recombinant strain demonstrated a significant 13.98% detoxification of DON after 72 h of fermentation (p < 0.05), as confirmed by HPLC–MS, while the strain expressing only the PQQ cluster showed no detoxification activity. This study establishes an integrated yeast cell factory for DON detoxification and highlights key limitations to guide future optimization efforts. Full article

Copper is a crucial cofactor that sustains multiple cellular electron-transfer reactions, making it an essential element for life. However, cytotoxic levels of copper can cause structural damage and cell death through the production of reactive oxygen species (ROS) and nonspecific attacks on proteins. Moreover, immune cells, including neutrophils and macrophages, accumulate copper to induce oxidative bursts that kill engulfed pathogens. Therefore, a well-regulated copper homeostasis system is required for the human commensal fungus Candida albicans to thrive in extreme host environments. Remarkably, C. albicans exhibits higher copper tolerance than the nonpathogenic model yeast Saccharomyces cerevisiae, suggesting the presence of a specific copper tolerance mechanism that supports its adaptability to copper stress. Ndt80 is a versatile transcription factor that regulates several biological processes in C. albicans, ranging from morphological control to drug resistance. This study further reveals that Ndt80 may contribute to copper tolerance by regulating copper transporters and copper-dependent superoxide dismutases (Sods). Additionally, RNA sequencing and complementary approaches uncovered the involvement of Ndt80 in plasma membrane integrity and mitochondrial respiration under copper stress, further linking Ndt80 to copper tolerance. Together, these results broaden our understanding of Ndt80 functions and provide new insights into copper tolerance in C. albicans. Full article

Lycium barbarum–Polygonatum cyrtonema composite jiaosu (LBPCJ) was prepared by sequential dual-species fermentation and evaluated in a mouse model of alcohol-induced liver injury. Following process optimization, a yeast-first sequential strategy with intermediate pasteurization was selected, comprising an initial Saccharomyces cerevisiae fermentation step, intermediate pasteurization, and a subsequent Lactiplantibacillus plantarum fermentation step. Fermentation reduced pH from 4.68 to 3.51 and increased total acidity from 61.06 to 135.39 g LA/L and total phenolic content from 3.01 to 9.39 mg GAE/mL. In vitro antioxidant-related activities were also higher after fermentation, with DPPH, ABTS, and •OH scavenging rates increasing by 39.90%, 29.78%, and 11.10%, respectively. In mice, LBPCJ administration was associated with lower liver index and serum aminotransferase levels, together with attenuated hepatic histopathological alterations, with the high-dose group (15 mL/kg BW) showing the clearest response. These changes were accompanied by higher hepatic SOD and GSH levels and lower MDA, TNF-α, IL-1β, and IL-6 levels. LBJ and PCJ also improved several measured indicators, while LBPCJ showed changes across multiple endpoints under the tested conditions. Overall, sequential fermentation markedly altered the physicochemical and antioxidant-related properties of LBPCJ, and LBPCJ administration improved multiple indicators related to alcohol-induced liver injury in mice, although the specific constituents and underlying mechanisms remain to be clarified. Full article

Consumer interest in low-SO₂ white wines is increasing; however, such approaches may reduce compositional and sensory predictability. This study evaluates how three fermentation strategies—SO₂ addition and Saccharomyces cerevisiae ES181 inoculation (SO₂Sc), spontaneous fermentation (NoSO₂-Spont), and inoculation with S. cerevisiae ES181 without SO₂ addition (NoSO₂Sc)—shape the chemical profile, polyphenolic composition, colour, microbiological status, and sensory perception of ‘Solaris’ wines relative to the must (reference). A single batch of ‘Solaris’ must (one press run) was split into three variants and fermented under identical temperature conditions (12 ± 0.5 °C), followed by cool ageing and natural sedimentation prior to bottling. Basic oenological parameters, selected fermentation by-products, viable yeast counts, CIE Lab colour, targeted polyphenolics (phenolic acids, flavonols, flavan-3-ols, and stilbenes), PCA of by-products, and blind sensory evaluation were assessed. The NoSO₂-Spont variant showed reduced fermentation completeness (higher residual sugars and lower ethanol) and the highest volatile acidity, together with elevated glycerol and several higher alcohols, and received the lowest sensory ratings. The SO₂Sc variant yielded the most controlled outcome, with the lowest volatile acidity, the brightest colour (higher L*, lower b*), and the highest sensory acceptance. The NoSO₂Sc variant produced intermediate sensory scores and a higher total phenolic content; however, volatile acidity remained high and viable yeast counts were the greatest, indicating increased susceptibility to microbiological activity during extended pre-bottling handling. Overall, the SO₂Sc strategy provides the greatest chemical stability and sensory acceptance, whereas low-SO₂ regimes require a hurdle approach (oxygen control, residual sugar management, hygiene, and stabilisation) to limit spoilage development and post-bottling refermentation. Full article

Weaning impairs intestinal function and growth performance in piglets. This study evaluated a fermented herbal formulation (FHF) composed of five bioactive herbal ingredients—Radix isatidis, Folium isatidis, Radix scutellariae, Fructus forsythiae, and Radix glycyrrhizae—fermented with Enterococcus faecium and Saccharomyces cerevisiae and characterized by flavonoids, phenolic acids, and hydroxylated fatty acids, using the porcine intestinal epithelial cell line (IPEC-J2) and weaned piglets. In vitro, IPEC-J2 cells were pretreated with FHF extract (100–1000 μg/mL) for 3 h prior to lipopolysaccharide (LPS) challenge. In vivo, 72 piglets were weaned at 32 days of age and, after a 3-day post-weaning adaptation period, entered a 35-day feeding trial. The piglets were then randomly assigned to three treatment groups: control (basal diet), A1 (basal diet + 0.4% FHF), and A2 (basal diet + 0.6% FHF during days 1–18, followed by 0.3% FHF during days 19–35). FHF dose-dependently alleviated the LPS-induced decrease in cell viability and suppressed IL-6, IL-8, IL-1β, and TNF-α expression. In piglets, the A2 group showed higher final body weight, average daily gain (ADG), and average daily feed intake (ADFI), lower feed conversion ratio (FCR), and a lower diarrhea rate than the control group. FHF also improved intestinal morphology, reduced serum TNF-α and diamine oxidase (DAO) levels, increased jejunal tight junction protein expression, enriched Limosilactobacillus and Lactobacillus, and elevated acetic and butyric acids. FHF improved intestinal health and growth performance in weaned piglets, with the A2 group showing the best overall efficacy. Full article

Polyamines, putrescine, spermidine and spermine, are essential polycationic metabolites present in all eukaryotic cells, where they regulate fundamental processes including nucleic acid stabilization, translation, and stress responses. Spermidine synthase (SPDS), a member of the aminopropyltransferase (APT) family, catalyzes the transfer of an aminopropyl group from decarboxylated S-adenosylmethionine (dc-SAM) to putrescine to form spermidine. Although genomic analyses predict the presence of SPDS homologs in multiple fungal species, polyamine biosynthesis has not been experimentally characterized in the multidrug-resistant fungal pathogen Candidozyma auris. Here, we report the biochemical and functional characterization of the C. auris spermidine synthase, CauSpe3. The CauSPE3 gene complemented a Saccharomyces cerevisiae spe3Δ mutant demonstrating conserved function in vivo. Recombinant CauSpe3 was expressed in Escherichia coli, purified and analyzed using the fluorescence-based DAB-APT assay, which uses 1,2-diacetylbenzene (DAB) for polyamine detection. CauSpe3 catalyzed efficient conversion of putrescine to spermidine in the presence of dc-SAM, with K_half values of 65.5 ± 7.11 µM for putrescine and 66.9 ± 2.09 µM for dc-SAM, and V_max values of 7.1 ± 0.57 and 7.9 ± 0.12 nmol·µg⁻¹·min⁻¹, respectively. A catalytic-site mutant and heat-inactivated enzyme showed no detectable activity, and product formation was confirmed by means of thin-layer chromatography and mass spectrometry. These findings establish CauSpe3 as a functional spermidine synthase. Full article

The gut microbiome plays a central role in human health, and probiotics are widely used to support microbial balance, though their efficacy depends on multiple factors. This study assessed the potential of commercial probiotics Saccharomyces cerevisiae var. boulardii, Weizmannia coagulans and Lacticaseibacillus rhamnosus by evaluating in vitro gastrointestinal kinetics, pharmaceutical stability, and antioxidant effects in chamomile tea. Growth across a broad pH range was modeled kinetically, while survival and inactivation were quantified in simulated gastric and intestinal fluids. Antibiotic and antifungal susceptibility was determined using disk diffusion, and antioxidant activity of fortified chamomile tea was assessed via DPPH radical scavenging. Results revealed distinct strain-dependent responses. S. cerevisiae var. boulardii and W. coagulans showed the highest gastrointestinal tolerance. The increase in fluid volume reduced survival during the gastric phase but improved survival in the intestinal phase, reflecting different stress responses. Antimicrobial susceptibility also varied, with S. cerevisiae var. boulardii exhibiting the highest resistance. Probiotic fortification enhanced chamomile tea’s antioxidant capacity, particularly for S. cerevisiae var. boulardii and L. rhamnosus. These findings provide quantitative insight into strain- and volume-dependent gastrointestinal performance, guiding the optimization of capsule formulations and the development of clean-label products combining probiotic and antioxidant benefits. Full article

During alcoholic fermentations, some non-Saccharomyces yeasts are often displaced by Saccharomyces cerevisiae. It remains unclear whether this displacement is mediated by metabolites produced by S. cerevisiae or depends on cell–cell contact. This study evaluated the effects of extracellular metabolites produced by S. cerevisiae on the growth and fermentative performance of Kluyveromyces marxianus isolated from mezcal fermentations. The development of both yeasts was evaluated in monocultures and in co-cultures with physical contact. Indirect interaction was also tested by exchanging cell-free fermented media. The growth and fermentative response of K. marxianus in cell-free S. cerevisiae-fermented medium showed modulation that depended on the growth phase during which the exchange was performed. The exchange performed at 6 h (exponential phase) limited the maximum growth of K. marxianus and resulted in lower fermentative performance. When the exchange was done during the stationary phase (17.5 h), K. marxianus exhibited a longer stationary phase and better fermentative performance. Finally, when the exchange was performed at 24 h (the beginning of the death phase), the effects on survival and fermentative performance were less pronounced. Furthermore, co-culture with cell–cell contact showed that direct competition and/or mechanisms dependent on physical contact intensify the displacement of K. marxianus. The results show that direct cell–cell contact promotes greater inhibition of K. marxianus by S. cerevisiae, which is relevant for the design of mixed fermentations aimed at achieving a greater contribution of non-Saccharomyces yeasts to the organoleptic characteristics of alcoholic beverages. Full article

This study evaluated the fermentative potential of eight industrial strains of Saccharomyces cerevisiae for producing mead from honeys originating from the Caatinga Biome in the semi-arid region of Pernambuco, Brazil. Despite presenting similar ethanol yields around 0.38 g/g, the strains differed in fermentation rate, residual sugar profile, and metabolic composition of the final products. Saccharomyces cerevisiae strains Renaissance TR313 and Fermol Distiller JP1 were selected for more detailed analyses, with JP1 standing out for its higher volumetric productivity (0.23 g/L/h) and shorter fermentation time of 20 days. Further fermentations demonstrated that increasing biomass, supplementing with the inorganic nitrogen source ammonium sulphate, or cell immobilization accelerates fermentation without compromising yield. Thus, the JP1 strain shows promise as a ferment for producing regionally identified mead from honeys typical of the Caatinga biome of the semi-arid Northeast of Brazil. The use of this strain with the honey of the Sertão can characterize the regional product and increase its value. Full article

Spontaneously fermented wines are a habitat for many Saccharomyces and non-Saccharomyces strains that are typical for a given region. The isolates obtained can serve as regional starter cultures for winemaking. The aim of this study was to isolate, identify and evaluate the oenological properties and fermentation suitability of selected yeast isolates obtained from Polish spontaneously fermented grape wines. The isolated yeasts were genetically identified and characterised in terms of ethanol tolerance, enzymatic activities, H₂S production, and preliminary killer activity. In small-scale fermentations conducted in CDGJ medium and grape juice, the fermentation rate, pH, number of yeast, content of sugars, ethanol, organic acids and volatile compounds were determined. Genetic identification revealed the species: Saccharomyces cerevisiae, S. paradoxus, Metschnikowia pulcherrima, M. ziziphicola, Hanseniaspora uvarum, and Pichia kluyveri. Non-Saccharomyces and Saccharomyces strains grew poorly in the presence of 4–6% (v/v) and 14–16% (v/v) ethanol, respectively. The yeasts had varied enzymatic activities in API ZYM tests, and production of H₂S, but did not exhibit killer activity. The monocultures showed differences in fermentation rates. The best growth was recorded for all strains during grape juice fermentation, up to 10⁹ cfu/mL, producing ethanol and glycerol in the range of 53.92–86.54 g/L and 0.0–4.48 g/L. Yeasts produced characteristic volatile compounds, e.g., esters: 2-phenylethyl acetate and ethyl decanoate. The monocultures of isolated yeasts can be used in fermentation of grape must, yielding wines with diverse characteristics in terms of ethanol, organic acids and volatile compounds. Full article

Water kefir grains are complex probiotic granules that can efficiently ferment fruit and vegetable juices and significantly improve product flavor. However, the mechanisms of flavor formation remain unclear, which limits the process optimization of this technology. This study investigated the mechanisms involved in flavor formation during the fermentation of strawberry juice with water kefir grains. The results showed that as fermentation progressed, the total acidity increased, whereas the pH value and soluble solids content decreased. Additionally, the contents of citric acid and malic acid gradually decreased with fermentation, while the contents of lactic, acetic, and succinic acid increased, and three soluble sugars showed reduced levels. A total of 218 volatile compounds were identified. Eight dominant bacterial genera and one dominant yeast species were detected. Significant correlations between some key microorganisms and flavor compounds were observed. Specifically, Lactiplantibacillus was positively correlated with hexyl acetate. Meanwhile, Gluconobacter and Acetobacter were positively correlated with methyl (Z,Z)-9,12-octadecadienoate, isoamyl acetate, etc. In contrast, LAB such as Lacticaseibacillus and Schleiferilactobacillus showed the opposite correlations with these key flavor compounds. Saccharomyces showed a positive correlation with ethyl palmitate, ethyl propionate, phenylsuccinic acid, and 1-pentanol. The main flavor compound metabolic pathways were predicted and they were significantly related with yeasts, acetic acid bacteria, and lactic acid bacteria. Overall, this study offers a theoretical basis for the directional regulation and optimization of the flavor quality of strawberry juice fermented with water kefir. Full article

Lipid nanodiscs are synthetic nanoparticles capable of solubilizing lipophilic drugs and have been shown to improve the potency of the antifungal Amphotericin B (AmphB) against various fungal pathogens. In this study, the SpyCatcher–SpyTag covalent labeling system was used to couple AmphB-loaded Apolipoprotein A1 (ApoA1) lipid nanodiscs to the receptor domain of Dectin-1, which binds to β-1,3/1,6 glucans present in many fungal cell walls. Denaturing protein gel electrophoresis demonstrated that ApoA1-SpyTag003 lipid nanodiscs could be covalently labeled with SpyCatcher003-Dectin-1-superfolder GFP (sfGFP). In microtiter growth assays with Saccharomyces cerevisiae, Dectin-1 AmphB nanodiscs displayed an IC₅₀ 1.5-fold lower than uncoupled AmphB nanodiscs and 2.8-fold lower than AmphB-only controls. Nanodiscs without AmphB and SpyCatcher003-Dectin-1-sfGFP themselves did not inhibit yeast growth. Fluorescence microscopy showed that SpyCatcher003-Dectin-1-sfGFP binds to yeast cell walls and accumulated at hot spots, matching the budding scar enrichment pattern previously described for other Dectin-1 fusion proteins. Together these results indicate that Dectin-1 fusions can target AmphB-loaded lipid nanodiscs to fungal cell walls and improve drug delivery. The results here establish the use of a modular SpyCatcher–SpyTag coupling system for targeting drug-loaded lipid nanodiscs to different cells or tissues, thereby increasing drug retention at infection sites, increasing drug potency, and reducing harmful side-effects. Full article

Climate change presents a challenge for global viticulture due to rising temperatures and water stress, which accelerate grape ripening, increase sugar levels, and reduce acidity. This compromises wine quality and microbial stability, resulting in higher reliance on sulfur dioxide (SO₂). However, SO₂ can inhibit desirable fermentations, including those carried out by non-Saccharomyces yeasts, which are key biotechnological tools for climate adaptation due to their ability to modulate acidity, aroma, and ethanol. Therefore, alternative disinfection methods are needed to control wild microbiota without hindering inoculated yeasts. This review critically analyzes ozone (O₃) as a non-thermal disinfection technology for winemaking. It examines the antimicrobial mechanism of ozone, its efficacy against wine-related microorganisms, its impact on the physicochemical and aromatic parameters of grapes, and its practical viability. Ozone effectively reduces spoilage-causing microbiota, achieving inactivation of approximately 3–4 log CFU/mL for yeasts, while preserving crucial grape compounds and providing a favorable environment for novel fermentation biotechnologies. Compared to other emerging technologies and SO₂, ozone offers a balanced profile: effective disinfection, minimal residues, cost-effectiveness, and compatibility with sustainable winemaking. Ozone is emerging as a promising alternative to facilitate controlled fermentations and improve wine quality among the current climatic and oenological challenges. Full article