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An increase in the consumer demand and the availability of gluten-free products has led to several brewers investigating brewing with grains other than barley. The primary grain of choice has been sorghum. These new gluten-free beers have a unique flavor and aroma, which previous research has shown is the result of differences in concentration for key chemical compounds, including ethyl butyrate, butyl acetate, isoamyl acetate, ethyl caproate, hexyl acetate, 1-octanol, nonanal, ethyl octanoate, and ethyl decanoate. This study focused looked at the influence different strains of yeast had on the concentration of these key compounds. Beer was brewed using either barley or sorghum malt extract. The concentrations of these key volatile compounds were determined using Solid Phase Microextraction (SPME) with Gas Chromatography and Mass Spectral (GC-MS) detection. Overall, it was found that the concentrations of these compounds were statistically different in the beers brewed from these two grain types. However, the yeast strain had no significant impact on the concentrations. [ABSTRACT FROM AUTHOR]

Kefir, a fermented milk beverage, is recognized for its potential health benefits, including its cholesterol-lowering properties. This study demonstrated that selected kefir starter cultures, including Lactococcus strains and yeasts, significantly reduce cholesterol-binding capacity under simulated gastrointestinal conditions, underscoring the challenges of probiotic delivery. We compared the performance of these cultures under laboratory conditions (growth broths) and simulated digestive juice models. Lactococcus strains showed significant differences in cholesterol binding between the two environments, highlighting the limitations of relying solely on laboratory testing. Yeast cultures also exhibited greater cholesterol binding in their native broths, but their survival was limited in digestive models. Our findings suggest that effective probiotic formulations should prioritize strains with high cholesterol-binding capacity and robust survival rates throughout the digestive tract. This study provides valuable insights for future research on the mechanisms behind these functionalities and the potential of kefir yeast strains for use in human digestive models. Our results can be used to inform the development of improved probiotic formulations for cholesterol management. [ABSTRACT FROM AUTHOR]

Simple Summary: Mitochondrial respiratory chain subunits are encoded by both mitochondrial and nuclear genomes, imposing evolutionary constraints due to potential incompatibilities between mutations in these genomes. Our study demonstrates that swapping mitochondrial DNA (mtDNA) between two laboratory yeast strains increases the frequency of mtDNA loss and reduces their respiratory capacity, suggesting coadaptation of mitochondrial and nuclear genomes at the intraspecific level. We also show that the ability of selfish mtDNA to displace other variants in heteroplasmic yeast cells depends primarily on their mtDNA sequences rather than the nuclear genome background. These findings underscore the complex interactions between mitochondrial and nuclear genomes. Unlike most animals, some fungi, including baker's yeast, inherit mitochondrial DNA (mtDNA) from both parents. When haploid yeast cells fuse, they form a heteroplasmic zygote, whose offspring retain one or the other variant of mtDNA. Meanwhile, some mutant mtDNA (rho−), with large deletions in the nucleotide sequence, can displace wild-type (rho+) mtDNA. Consequently, offspring of zygotes with such rho− mtDNA predominantly carry the mutant variant. This phenomenon is called suppressivity. In this study, we investigated how the suppressivity of rho− mtDNA depends on the mitochondrial and nuclear genomes of the rho+ strain during crossing. Comparing two diverged laboratory strains, SK1 and W303, we measured suppressivity in crosses with four rho− strains. One rho− strain showed significantly higher suppressivity when crossed with SK1 than with W303. We then created cytoplasmic hybrids by swapping mtDNAs between these strains. Surprisingly, we found that the mtDNA of the rho+ strain, rather than its nuclear DNA, determines high suppressivity in crosses of SK1 rho+ with the rho− strain. Additionally, mtDNA replacement reduced respiration rate and growth rate on non-fermentable substrates while increasing the likelihood of functional mtDNA loss. Our data demonstrate that a mutant mtDNA variant's ability to displace another mitochondrial DNA variant in a heteroplasmic cell depends more on mtDNA sequences than on the biochemical and structural context created by the nuclear genome background. [ABSTRACT FROM AUTHOR]

Simple Summary: In this study, we employ computational methods to identify genes that may influence the translation of structured mRNAs, namely PGM2 and other synthetic mRNAs. We found two candidates, CAF20 and ECM32 that when deleted affect the translation of PGM2 and synthetic mRNAs with structured 5'untranslated regions. These findings suggest that CAF20 and ECM32 have some involvement in the translation of structured mRNAs, expanding our understanding of mechanisms that influence gene regulation. Translation is a fundamental process in biology, and understanding its mechanisms is crucial to comprehending cellular functions and diseases. The regulation of this process is closely linked to the structure of mRNA, as these regions prove vital to modulating translation efficiency and control. Thus, identifying and investigating these fundamental factors that influence the processing and unwinding of structured mRNAs would be of interest due to the widespread impact in various fields of biology. To this end, we employed a computational approach and identified genes that may be involved in the translation of structured mRNAs. The approach is based on the enrichment of interactions and co-expression of genes with those that are known to influence translation and helicase activity. The in silico prediction found CAF20 and ECM32 to be highly ranked candidates that may play a role in unwinding mRNA. The activities of neither CAF20 nor ECM32 have previously been linked to the translation of PGM2 mRNA or other structured mRNAs. Our follow-up investigations with these two genes provided evidence of their participation in the translation of PGM2 mRNA and several other synthetic structured mRNAs. [ABSTRACT FROM AUTHOR]

Brettanomyces yeasts play a relevant role in the fermentation industry, showing controversial behavior. There is growing interest in these yeasts in the fermentation industry as beer and bioethanol production, while in winemaking, they are considered spoilage microorganisms mainly used to produce ethyl phenols. These compounds may alter wine's organoleptic characteristics, leading to significant economic loss. In this work, 45 Brettanomyces strains from seven different environments were genotyped and assayed for some oenological characters to investigate the possible relationship among sources of isolation, genotype characterization, and oenological characters. The results of biotyping showed four main clusters which were also distinguished according to the oenological characters. The oenological characters also distinguished the strains based on the isolation source, suggesting an overall relation between origin and biotypes. The negative correlation between fermentation rate and ethyl phenols production in the Brettanomyces population may indicate the adaptation to hostile environments differently from crop strains that showed the opposite behavior. The overall results contribute to clarifying some features of Brettanomyces yeasts, even if further investigations into the ability of these yeasts to colonize winemaking environments are needed. [ABSTRACT FROM AUTHOR]

Glycogen, a branched polysaccharide organized into glycogen granules (GGs), is delivered from the cytoplasm to the lysosomes of hepatocytes by STBD1-driven selective autophagy (glycophagy). Recently, we developed Komagataella phaffii yeast as a simple model of GG autophagy and found that it proceeds non-selectively under nitrogen starvation conditions. However, another group, using Saccharomyces cerevisiae as a model, found that glycogen is a non-preferred cargo of nitrogen starvation-induced bulk autophagy. To clarify cargo characteristics of K. phaffii GGs, we used the same glycogen synthase-based reporter (Gsy1-GFP) of GG autophagy in K. phaffii as was used in S. cerevisiae. The K. phaffii Gsy1-GFP marked the GGs and reported on their autophagic degradation during nitrogen starvation, as expected. However, unlike in S. cerevisiae, glycogen synthase-marked GGs were delivered to the vacuole and degraded there with the same efficiency as a cytosolic glycogen synthase in glycogen-deficient cells, suggesting that glycogen is a neutral cargo of bulk autophagy in K. phaffii. We verified our findings with a new set of reporters based on the glycogen-binding CBM20 domain of human STBD1. The GFP-CBM20 and mCherry-CBM20 fusion proteins tagged GGs, reported about the autophagy of GGs, and confirmed that GGs in K. phaffii are neither preferred nor non-preferred substrates of bulk autophagy. They are its neutral substrates. [ABSTRACT FROM AUTHOR]

The cytosolic calcium concentration ([Ca2+]cyt) in yeast cells is maintained at a low level via the action of different transporters sequestrating these cations in the vacuole. Among them, the vacuolar Ca2+ ATPase Pmc1 crucially contributes to this process. Its inactivation in Ogataea yeasts was shown to cause sodium dodecyl sulfate (SDS) hypersensitivity that can be alleviated by the inactivation of the plasma membrane high-affinity Ca2+ channel Cch1. Here, we show that SDS at low concentrations induces a rapid influx of external Ca2+ into cells, while the plasma membrane remains impermeable for propidium iodide. The inactivation of Pmc1 disturbs efficient adaptation to this activity of SDS. The inactivation of Cch1 partially restores the ability of pmc1 mutant cells to cope with an increased [Ca2+]cyt that correlates with the suppression of SDS hypersensitivity. At the same time, Cch1 is unlikely to be directly involved in SDS-induced Ca2+ influx, since its inactivation does not decrease the amplitude of the rapid [Ca2+]cyt elevation in the pmc1-Δ mutant. The obtained data suggest that the effects of CCH1 inactivation on SDS sensitivity and coping with increased [Ca2+]cyt are related to an additional Cch1 function beyond its direct involvement in Ca2+ transport. [ABSTRACT FROM AUTHOR]

The use of probiotics has been gaining popularity in terms of inclusion into human diets over recent years. Based on properties exerted by these organisms, several benefits have been elucidated and conferred to the host. Bacteria have been more commonly used in probiotic preparations compared to yeast candidates; however, yeast exhibit several beneficial properties, such as the prevention and treatment of diarrhea, the production of antimicrobial agents, the prevention of pathogen adherence to intestinal sites, the maintenance of microbial balance, the modulation of the immune system, antibiotic resistance, amongst others. Saccharomyces boulardii is by far the most studied strain; however, the potential for the use of other yeast candidates, such as Kluyveromyces lactis and Debaryomyces hansenii, amongst others, have also been evaluated in this review. Furthermore, a special focus has been made regarding the production considerations for yeast-based probiotics and their formulation into different delivery formats. When drafting this review, evidence suggests that the use of yeasts, both wild-type and genetically modified candidates, can extend beyond gut health to support skin, the respiratory system, and overall immune health. Hence, this review explores the potential of yeast probiotics as a safe, effective strategy for preventative health in humans, highlighting their mechanisms of action, clinical applications, and production considerations. [ABSTRACT FROM AUTHOR]

The aroma-active compounds produced by Saccharomyces cerevisiae during the fermentation of wort are key to the unique aroma and flavour profiles of beer. In commercial fermentations, there is batch-to-batch variation depending on yeast "brewing fitness" or the health of the yeast, but how does yeast health impact fermentation performance and metabolite production during fermentation? To address this, daily samples were collected from three full-scale commercial fermentations. The specific gravity was measured immediately, and samples were collected for carbohydrate analysis by High-Performance Liquid Chromatography and volatile compound analysis by Head-Space Gas Chromatography Mass Spectrometry (HS-GC-MS). Acetate esters (3), medium-chain fatty acid ethyl esters (7), hop-derived compounds (3), and an off-flavour (1) were detected and identified, and their relative signal was recorded for each sample. While there did not appear to be an effect of generational age on the duration of fermentation, age, in terms of the number of generations from serial re-pitching, impacted the ratios of volatile compounds. This difference in ratios was observed as early as Day 2, resulting in a difference in the volatile compound profiles of finished beers, therefore resulting in inconsistency in the product. This is important knowledge for brewers as generational age must be considered when fermenting high-quality, consistent products and monitoring fermentation progress/duration may not be enough to determine the ability of yeast to produce balanced flavour profiles. [ABSTRACT FROM AUTHOR]

The implementation of the circular bioeconomy is now widely accepted as a critical step towards reducing the environmental burden of industrial waste and reducing the impact of this waste on climate change. The valorisation of waste using microorganisms is an attractive and fast-developing strategy capable of achieving meaningful improvements in the sustainability of the biotechnology industry. Yeasts are a powerful chassis for developing valorisation strategies and key opportunities. Thus, this study examines how waste from the food sector can be effectively targeted for valorisation by yeast. Yeasts themselves are critically important elements in the production of food and brewing, and thus, the valorisation of waste from these processes is further reviewed. Policy and regulatory challenges that may impact the feasibility of industrial applications of yeast systems in the valorisation of food waste streams are also discussed. [ABSTRACT FROM AUTHOR]

Some potentially probiotic strains of lactic acid bacteria (LAB) and yeast that inhabit the digestive tract of humans are known to detoxify xenobiotics, including acrylamide (AA). The objective of the subsequent research was to evaluate the AA-detoxification capability of LAB and yeast isolated from various sources. Namely, the effect of AA was tested on the growth of LAB and yeast strains, as well in the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Subsequently, the AA-binding ability of LAB and yeast was investigated in various environments, including the pH, incubation temperature, cell density, and with inanimate cells. The ability of selected LAB and yeast to reduce the genotoxicity of AA was tested on Caco-2 and Hep-G2 cell lines. The results showed that all tested strains exhibited strong resistance to AA at concentrations of 5, 10, and 50 µg/mL. Also, AA was detected in the intracellular and membrane extracts of tested strains. The most effective binding strain was Pediococcus acidilactici 16 at pH = 5, cell density = 109 CFU/mL, and incubation temperature = 37 °C (87.6% of AA removed). Additionally, all tested strains reduced the genotoxicity of AA, with the greatest reduction observed at the highest concentration of 50 µg/mL. The phenomena of detoxification by potentially probiotic strains could reduce the toxic and harmful effects of AA exposure to humans every day. [ABSTRACT FROM AUTHOR]

Autophagosome (AP)–lysosome/vacuole fusion is one of the hallmarks of macroautophagy. Membrane features and changes during the fusion process have mostly been described using two-dimensional (2D) models with one AP and one lysosome/vacuole. The outer membrane (OM) of a closed mature AP has been suggested to fuse with the lysosomal/vacuolar membrane. However, the descriptions in some studies for fusion-related issues are questionable or incomplete. The correct membrane features of APs and lysosomes/vacuoles are the prerequisite for describing the fusion process. We searched the literature for representative membrane features of AP-related structures based on electron microscopy (EM) graphs of both animal and yeast cells and re-evaluated the findings. We also summarized the main 2D models describing the membrane changes during AP–lysosome/vacuole fusion in the literature. We used three-dimensional (3D) models to characterize the known and unknown membrane changes during and after fusion of the most plausible 2D models. The actual situation is more complex, since multiple lysosomes may fuse with the same AP in mammalian cells, multiple APs may fuse with the same vacuole in yeast cells, and in some mutant cells, phagophores (unclosed APs) fuse with lysosomes/vacuoles. This review discusses the membrane features and highly dynamic changes during AP (phagophore)–lysosome/vacuole fusion. The resulting information will improve the understanding of AP–lysosome/vacuole fusion and direct the future research on AP–lysosome/vacuole fusion and regeneration. [ABSTRACT FROM AUTHOR]

Identifying key genes involved in Cadmium (Cd) response pathways in plants and developing low-Cd-accumulating cultivars may be the most effective and eco-friendly strategy to tackle the problem of Cd pollution in crops. In our previous study, Stressseventy subfamily A 4 (SSA4) was identified to be associated with Cd tolerance in yeast. Here, we investigated the mechanism of SSA4 in regulating Cd tolerance in yeast. ScSSA4 binds to POre Membrane 34 (POM34), a key component of nuclear pore complex (NPC), and translocates from the cytoplasm to the nucleus, where it regulates the expression of its downstream gene, Viable in a Hal3 Sit4 background 1 (VHS1), resulting in reduced Cd accumulation in yeast cells. Additionally, we identified a Chinese cabbage SSA4 gene, BrSSA4c, which could enhance the Cd tolerance in Chinese cabbage. This study offers new insights into the regulatory mechanisms of Cd tolerance in yeast, a model organism, and paves the way for the genetic enhancement of Cd tolerance in Chinese cabbage. [ABSTRACT FROM AUTHOR]

In recent years, demand for low-alcohol and alcohol-free beers has been rising. Of the many methods of producing such beers, many have expensive implementation requirements or drawbacks in terms of beer quality. The exploration of non-Saccharomyces yeast species presents a promising opportunity to overcome these challenges. These yeasts, with their diverse metabolic capabilities and unique flavor profiles, offer the potential to create innovative and flavorful low-alcohol beers. The study investigates the feasibility of using selected non-Saccharomyces yeasts for brewing low-alcohol beers, focusing on fermentation kinetics, physicochemical parameters, and the sensory attributes of the final product. The evaluated yeast species were Kluyveromyces lactis MG971263, Metschnikowia pulcherrima MG971247 and MG971250, Torulaspora delbrueckii MG971248, Wickerhamomyces anomalus MG971261, and W. onychis MG971246. Two strains of Saccharomyces cerevisiae were used as a control. The results of the study show that selected non-Saccharomyces yeast species might be used to produce low-alcohol beers. The non-Saccharomyces yeast allowed the researchers to obtain beers with an alcohol content in the range of 0.5–1.05%, while the control beer brewed with US-05 had an alcohol content of 3.77%. Among the evaluated strains, the strains M. pulcherrima MG971250 and T. delbrueckii MG971248 were found to be rated better in a sensory evaluation than the brewed and low-alcohol strains of S. cerevisiae. [ABSTRACT FROM AUTHOR]

Ensuring sustainability has increasingly become a significant concern not only in aquaculture but in the general agrifood sector. Therefore, it is imperative to investigate pathways to feed substitutes/best practices to enhance aquaculture sustainability. The application of fungi in aquaculture provides innovative methods to enhance the sustainability and productivity of aquaculture. Fungi play numerous roles in aquaculture, including growth, immunity enhancement and disease resistance. They also play a role in bioremediation of waste and bioflocculation. The application of fungi improves the suitability and utilization of terrestrial plant ingredients in aquaculture by reducing the fibre fractions and anti-nutritional factors and increasing the nutrients and mineral contents of plant ingredients. Fungi are good flotation agents and can enhance the buoyancy of aquafeed. Pigments from fungi enhance the colouration of fish fillets, making them more attractive to consumers. This paper, via the relevant literature, explores the multifaceted roles of fungi in aquaculture, emphasizing their potential to transform aquaculture through environmentally friendly and sustainable techniques. The effectiveness of fungi in reducing fibre fractions and enhancing nutrient availability is influenced by the duration of fermentation and the dosage administered, which may differ for various feed ingredients, making it difficult for most aquaculture farmers to apply fungi approximately. Therefore, the most effective dosage and fermentation duration for each feed ingredient should be investigated. [ABSTRACT FROM AUTHOR]

Limited antifungal treatment options and drug resistance require innovative approaches to effectively combat fungal infections. Combination therapy is a promising strategy that addresses these pressing issues by concurrently targeting multiple cellular sites. The drug targets usually selected for combination therapy are from different cellular pathways with the goals of increasing treatment options and reducing development of resistance. However, some circumstances can prevent the implementation of combination therapy in clinical practice. These could include the increased risk of adverse effects, drug interactions, and even the promotion of drug resistance. Furthermore, robust clinical evidence supporting the superiority of combination therapy over monotherapy is limited and underscores the need for further research. Despite these challenges, synergies detected with different antifungal classes, such as the azoles and echinocandins, suggest that treatment strategies can be optimized by better understanding the underlying mechanisms. This review provides an overview of multi-targeting combination strategies with a primary focus on Candidozyma auris infections. [ABSTRACT FROM AUTHOR]

This study evaluated natural extracts from plant biomass for UV protection and oxidative stress reduction. Conducted in Bucharest, Romania, it focused on medicinal mushrooms and pomegranate bark. The biotechnological process involved a two-phase extraction: hot water processing of Ganoderma lucidum, Hericium erinaceus, Inonotus obliquus, and Tremella mushrooms, followed by ethanol extraction with pomegranate bark and green tea. The spectrophotometric analysis identified phenolics and flavonoids. The ethanol extract showed higher phenolic content and antioxidant activity, particularly in DPPH radical scavenging. UVB exposure tests demonstrated its protective effect, comparable to vitamin B3, delaying oxidative stress onset by 30 min. This research underscores the potential of using natural biomass extracts in skincare, promoting environmental sustainability and economic viability by converting agricultural waste into valuable bioactive compounds. [ABSTRACT FROM AUTHOR]

Simple Summary: This paper provides an overview of the key issues concerning the use of yeast products as an alternative protein source and feed additives to develop a more sustainable and environmentally friendly aquaculture. The use of yeast is presented in detail, with a particular focus on its use as a primary protein source and as a supplement (such as probiotics and immune stimulants). Additionally, the digestibility of yeasts and their use in live aquafeed culture are discussed in detail. The aquafeed industry increasingly relies on using sustainable and appropriate protein sources to ensure the long-term sustainability and financial viability of intensive aquaculture. Yeast has emerged as a viable substitute protein source in the aquaculture sector due to its potential as a nutritional supplement. A substantial body of evidence exists to suggest that yeast has the potential to act as an effective immune-stimulating agent for a range of aquaculture fish species. Furthermore, the incorporation of yeast supplements and feed additives has the potential to bolster disease prevention, development, and production within the aquaculture sector. Except for methionine, lysine, arginine, and phenylalanine, which are typically the limiting essential amino acids in various fish species, the various yeast species exhibit amino acid profiles that are advantageous when compared to fishmeal. The present review considers the potential nutritional suitability of several yeast species for fish, with particular attention to the various applications of yeast in aquaculture nutrition. The findings of this study indicate that the inclusion of yeast in the diet resulted in the most favorable outcomes, with improvements observed in the overall health, growth performance, and nutritional condition of the fish. Digestibility, a key factor in sustainable feed development, is discussed in special detail. Additionally, this review addresses the utilization of yeast as an immunostimulating agent for fish and its digestion in fish. Furthermore, the research emphasizes the necessity of large-scale production of yeast as a substitute for fishmeal in aquaculture. [ABSTRACT FROM AUTHOR]

Retrotransposons are mobile DNA elements that are more active with increasing age and exacerbate aging phenotypes in multiple species. We previously reported an unexpected extension of chronological lifespan in the yeast, Saccharomyces paradoxus, due to the presence of Ty1 retrotransposons when cells were aged under conditions of mild stress. In this study, we tested a subset of genes identified by RNA-seq to be differentially expressed in S. paradoxus strains with a high-copy number of Ty1 retrotransposons compared with a strain with no retrotransposons and additional candidate genes for their contribution to lifespan extension when cells were exposed to a moderate dose of hydroxyurea (HU). Deletion of ADE8, NCS2, or TRM9 prevented lifespan extension, while deletion of CDD1, HAC1, or IRE1 partially prevented lifespan extension. Genes overexpressed in high-copy Ty1 strains did not typically have Ty1 insertions in their promoter regions. We found that silencing genomic copies of Ty1 prevented lifespan extension, while expression of Ty1 from a high-copy plasmid extended lifespan in medium with HU or synthetic medium. These results indicate that cells adapt to expression of retrotransposons by changing gene expression in a manner that can better prepare them to remain healthy under mild stress. [ABSTRACT FROM AUTHOR]

Background: This study aimed to verify whether adding a combination of additives (blend) to the diet of dairy calves after weaning can improve animal performance and health and influence the profile of ruminal short-chain fatty acids and intestinal microbiota. Methods: We used 35 Holstein calves, males, with an average age of 70 days and an average body weight of 68 kg. The treatments used were negative control (T-0: without additive), positive control (T-Control: flavomycin + monensin), T-500 (500 g blend/ton), T-1000 (1000 g blend/ton), and T-1500 (1500 g blend/ton). The additives were classified as zootechnical (probiotics, prebiotics, and essential oils of cinnamon and oregano) and nutritional additive (minerals). Results: Weight gain and daily weight gain were higher for calves in the T-Control, T-500, and T-1000 groups. The concentration of heavy-chain immunoglobulins was higher in the blood of calves in the T-Control and T-500 groups when compared to the other groups. In the T-1500 groups, higher levels of reactive oxygen species were observed, while, in the T-0 and T-1500 groups, higher levels of TBARS and glutathione S-transferase activity were detected. The 15 abundant microorganisms in the calves' feces, regardless of treatment, were Treponema suis, Treponema saccharophilum, Faecalibacterium prausnitzii, Pseudoflavonifractor sp., Roseburia faecis, Rikenellaceae, Enterobacteriaceae_f, Clostridium sp., Roseburia intestinalis, Aeromonadales_o, Prevotella copri, Treponema succinifaciens, Eubacterium sp., Treponema porcium, and Succinivibrio sp. The T-1000 group showed greater alpha diversity for the intestinal microbiota than T-Control, T-0, and T-500. The additive combination (T-1000) increased the bacterial activity in the ruminal fluid, and the animals of T-1000 had a higher concentration of short-chain fatty acids compared to T-0 and T-1500; this difference is because, in these calves, the production of acetic, butyric, and propionic acid increased. Conclusions: The combination of additives had positive effects on animal health, ruminal volatile fatty acid production, and intestinal microbiota, resulting in animals with more significant weight gain and feed efficiency. [ABSTRACT FROM AUTHOR]

Recent research has highlighted the effectiveness of starter inocula in fermentation processes. In this sense, this study examines the use of an inoculum composed of coffee pulp, mucilage broth, and microorganisms such as Saccharomyces cerevisiae, L. delbrueckii ssp. bulgaricus, and S. thermophilus in fermenting Castillo variety coffee. An inoculum was prepared, measuring variables such as the pH, acidity, °Brix, lactic acid bacteria, and yeast viability. Following optimization, the inoculum was evaluated in a fermentation process, evaluating the pH, °Brix, acidity, microbiological analysis, ochratoxin A, and cup quality post-drying and roasting. The findings demonstrated a significant reduction in the pH from 4.47 to 4.05 and in the °Brix from 15.8 to 8.45, indicating efficient organic acid production and sugar degradation. Acidity levels increased from 20.02 mg/g to 42.69 mg/g, while microbial viabilities remained above 107 CFUs/g, suggesting effective biomass production. The process effectively reduced the microbial load without detecting ochratoxin A. Sensory evaluations confirmed the enhanced cup quality, validating the positive impact of inoculum use in coffee fermentation. The results support the use of coffee pulp and mucilage broth as effective substrates for the growth of the evaluated microorganisms, and the application of starter cultures containing lactic acid bacteria and yeast can elevate the coffee to a specialty grade. [ABSTRACT FROM AUTHOR]

Human monocarboxylate transporters (hMCTs) belong to the solute carrier 16 (SLC16) family of proteins and are responsible for the bi-directional transport of various metabolites, including monocarboxylates, hormones, and aromatic amino acids. Hence, the metabolic role of hMCTs is undisputable, as they are directly involved in providing nutrients for oxidation and gluconeogenesis as well as participate in circulation of iodothyronines. However, due to the difficulty in obtaining suitable amounts of stable hMCT samples, the structural information available for these transporters is limited, hindering the development of effective therapeutics. Here we provide a straightforward, cost-effective strategy for the overproduction of hMCTs using a whole-cell Saccharomyces cerevisiae-based system. Our results indicate that this platform is able to provide three hMCTs, i.e., hMCT1 and hMCT4 (monocarboxylate transporters), and hMCT10 (an aromatic amino acid transporter). hMCT1 and hMCT10 are recovered in the quantity and quality required for downstream structural and functional characterization. Overall, our findings demonstrate the suitability of this platform to deliver physiologically relevant membrane proteins for biophysical studies. [ABSTRACT FROM AUTHOR]

The de novo synthesis of cytidine 5′-triphosphate (CTP) is catalyzed by the enzyme CTP synthase (CTPS), which is known to form cytoophidia across all three domains of life. In this study, we use the budding yeast Saccharomyces cerevisiae and the fission yeast Schizosaccharomyces pombe as model organisms to compare cytoophidium assembly under external environmental and intracellular CTPS alterations. We observe that under low and high temperature conditions, cytoophidia in fission yeast gradually disassemble, while cytoophidia in budding yeast remain unaffected. The effect of pH changes on cytoophidia maintenance in the two yeast species is different. When cultured in the yeast-saturated cultured medium, cytoophidia in fission yeast disassemble, while cytoophidia in budding yeast gradually form. Overexpression of CTPS results in the presence and maintenance of cytoophidia in both yeast species from the log phase to the stationary phase. In summary, our results demonstrate differential cytoophidium assembly between Saccharomyces cerevisiae and Schizosaccharomyces pombe, the two most studied yeast species. [ABSTRACT FROM AUTHOR]

This study aimed to provide novel information on the impact of indigenous non-Saccharomyces yeasts, including Metschnikowia chrysoperlae, Metschnikowia sinensis/shanxiensis, Metschnikowia pulcherrima, Lachancea thermotolerans, Hanseniaspora uvarum, Hanseniaspora guilliermondii, and Pichia kluyveri, on metabolites related to the metabolism of tryptophan, phenylalanine, and tyrosine. The experiment included two fermentation practices: monoculture and sequential fermentation with commercial Saccharomyces cerevisiae, using sterile Maraština grape juice. A targeted approach through ultrahigh-resolution liquid chromatography associated with mass spectrometry was used to quantify 38 metabolites. All the indigenous yeasts demonstrated better consumption of tryptophan in monoculture than in interaction with S. cerevisiae. M. sinensis/shanxiensis was the only producer of indole-3-carboxylic acid, while its ethyl ester was detected in monoculture fermentation with H. guilliermondii. H. guilliermondii consumed the most phenylalanine among the other isolates. 5-hydroxy-L-tryptophan was detected in fermentations with M. pulcherrima and M. sinensis/shanxiensis. M. pulcherrima significantly increased tryptophol content and utilised tyrosine in monoculture fermentations. Sequential fermentation with M. sinensis/shanxiensis and S. cerevisiae produced higher amounts of N-acetyl derivatives of tryptophan and phenylalanine, while H. guilliermondii-S. cerevisiae fermentation resulted in wines with the highest concentrations of L-kynurenine and 3-hydroxyanthranilic acid. P. kluyveri produced the highest concentration of N-acetyl-L-tyrosine in monoculture fermentations. These findings highlight the different yeast metabolic pathways. [ABSTRACT FROM AUTHOR]

Various microorganisms, referred to as kuratsuki microorganisms, inhabit each sake brewery. Previously, kuratsuki yeasts had been used for sake production in each sake brewery. Kuratsuki lactic acid bacteria have been used to produce kimoto, a fermentation starter. Kuratsuki non-lactic acid bacteria were examined to evaluate their potential roles and effects in sake production. The addition of kuratsuki bacteria to the sake-making process can change the flavor and taste of the sake. This change was observed in both the coculture experiments between sake yeast and kuratsuki bacteria and the sake making tests with and without kuratsuki bacteria. The comprehensive gene expression analysis of sake yeast cocultured with kuratsuki bacteria showed that 1.2% of the yeast genes were upregulated and 1.0% were downregulated following the addition of kuratsuki bacteria. This indicates that the change in flavor and taste of sake due to the addition of kuratsuki bacteria was caused by the interaction between sake yeast and kuratsuki bacteria. To understand the implications of kuratsuki bacteria in sake production, it is essential to study the interactions between sake yeast and kuratsuki bacteria. [ABSTRACT FROM AUTHOR]

Classifying a yeast strain into a recognized species is not always straightforward. Currently, the taxonomic delineation of yeast strains involves multiple approaches covering phenotypic characteristics and molecular methodologies, including genome-based analysis. The aim of this study was to evaluate the suitability of the Average Nucleotide Identity (ANI) calculation through FastANI, a tool created for bacterial species identification, for the assignment of strains to some yeast species. FastANI, the alignment of in silico-extracted D1/D2 sequences of LSU rRNA, and multiple alignments of orthologous genes (MAOG) were employed to analyze 644 assemblies from 12 yeast genera, encompassing various species, and on a dataset of hybrid Saccharomyces species. Overall, the analysis showed high consistency between results obtained with FastANI and MAOG, although, FastANI proved to be more discriminating than the other two methods applied to genomic sequences. In particular, FastANI was effective in distinguishing between strains belonging to different species, defining clear boundaries between them (cutoff: 94–96%). Our results show that FastANI is a reliable method for attributing a known yeast species to a particular strain. Moreover, although hybridization events make species discrimination more complex, it was revealed to be useful in the identification of these cases. We suggest its inclusion as a key component in a comprehensive approach to species delineation. Using this approach with a larger number of yeasts would validate it as a rapid technique to identify yeasts based on whole genome sequences. [ABSTRACT FROM AUTHOR]

This work aims to comprehend the dynamics of neurodegenerative disease using a mathematical model of fractional-order yeast prions. In the context of the Caputo fractional derivative, we here study and examine the solution of this model using the Predictor–Corrector approach. An analysis has been conducted on the existence and uniqueness of the selected model. Also, we examined the model's stability and the existence of equilibrium points. With the purpose of analyzing the dynamics of the Sup35 monomer and Sup35 prion population, we displayed the graphs to show the obtained solutions over time. Graphical simulations show that the behaviour of the populations can change based on fractional orders and threshold parameter values. This work may present a good example of how biological theories and data can be better understood via mathematical modelling. [ABSTRACT FROM AUTHOR]

Epiphytic yeasts represent an important source for the development of novel strategies aiming to combat food microbial contamination. The present study deals with the characterization of nine yeast strains belonging to Starmerella, Candida, Metschinikowia, Lachancea, Kodamaea and Pichia genera, isolated from the surface of plants from the Botanical Garden "Dimitrie Brandza" (Bucharest, Romania) for use as antimicrobial and probiotic agents. The tests involved the determination of the safe status, cell growth under stress conditions, and activity against pathogenic Candida and bacteria strains, respectively, as well as phytopathogenic filamentous fungi and lipolytic activity. None of the nine strains showed all the characteristics for virulence and pathogenicity, with the rare positive results being explained rather by their adaptability to the habitats of origin. The strains Lachancea thermotolerans CMGB-ST12 and Kodamaea ohmeri CMGB-ST19 grew at 37 °C; Metschnikowia reukaufii CMGB-ST21.2, M. reukaufii CMGB-ST.8.1 and M. reukaufii CMGB ST10 grew in the presence of 10% NaCl, while L. thermotolerans CMGB-ST12 and K. ohmeri CMGB-ST19 tolerated both acidic and alkaline pH values well (3.0 to 12.0). The studied yeast strains showed good antimicrobial activity against Candida krusei, Candida albicans and Gram-negative bacterial strains, with K. ohmeri CMGB-ST19 and Pichia membranaefaciens CMGB-ST53 inhibiting up to 100% the development of filamentous fungi. All the strains produced lipases for tributyrin hydrolysis, the best producer being Starmerella bombi CMGB-ST1, and only Candida magnoliae CMGB-ST8.2 tested positive against other probiotic yeasts. Overall, our nine yeast strains show high potential for industrial applications, for obtaining probiotic products and for preventing the development of a wide range of microbial food contaminants. [ABSTRACT FROM AUTHOR]

Transcriptional regulatory networks (TRNs) associated with recombinant protein (rProt) synthesis in Yarrowia lipolytica are still under-described. Yet, it is foreseen that skillful manipulation with TRNs would enable global fine-tuning of the host strain's metabolism towards a high-level-producing phenotype. Our previous studies investigated the transcriptomes of Y. lipolytica strains overproducing biochemically different rProts and the functional impact of transcription factors (TFs) overexpression (OE) on rProt synthesis capacity in this species. Hence, much knowledge has been accumulated and deposited in public repositories. In this study, we combined both biological datasets and enriched them with further experimental data to investigate an interplay between TFs and rProts synthesis in Y. lipolytica at transcriptional and functional levels. Technically, the RNAseq datasets were extracted and re-analyzed for the TFs' expression profiles. Of the 140 TFs in Y. lipolytica, 87 TF-encoding genes were significantly deregulated in at least one of the strains. The expression profiles were juxtaposed against the rProt amounts from 125 strains co-overexpressing TF and rProt. In addition, several strains bearing knock-outs (KOs) in the TF loci were analyzed to get more insight into their actual involvement in rProt synthesis. Different profiles of the TFs' transcriptional deregulation and the impact of their OE or KO on rProts synthesis were observed, and new engineering targets were pointed. [ABSTRACT FROM AUTHOR]

Riboflavin, an essential vitamin for humans, is extensively used in various industries, with its global demand being met through fermentative processes. Hyphopichia wangnamkhiaoensis is a novel dimorphic yeast species capable of producing riboflavin. However, the nutritional factors affecting riboflavin production in this yeast species remain unknown. Therefore, we conducted a kinetic study on the effects of various nutritional factors—carbon and energy sources, nitrogen sources, vitamins, and amino acids—on batch riboflavin production by H. wangnamkhiaoensis. Batch experiments were performed in a bubble column bioreactor to evaluate cell growth, substrate consumption, and riboflavin production. The highest riboflavin production was obtained when the yeast growth medium was supplemented with glucose, ammonium sulfate, biotin, and glycine. Using these chemical components, along with the mineral salts from Castañeda-Agullo's culture medium, we formulated a novel, low-cost, and effective culture medium (the RGE medium) for riboflavin production by H. wangnamkhiaoensis. This medium resulted in the highest levels of riboflavin production and volumetric productivity, reaching 16.68 mg/L and 0.713 mg/L·h, respectively, within 21 h of incubation. These findings suggest that H. wangnamkhiaoensis, with its shorter incubation time, could improve the efficiency and cost-effectiveness of industrial riboflavin production, paving the way for more sustainable production methods. [ABSTRACT FROM AUTHOR]

Redox homeostasis is the balance between oxidation and reduction reactions. Its maintenance depends on glutathione, including its reduced and oxidized form, GSH/GSSG, which is the main intracellular redox buffer, but also on the nicotinamide adenine dinucleotide phosphate, including its reduced and oxidized form, NADPH/NADP+. Under conditions that enable yeast cells to undergo fermentative metabolism, the main source of NADPH is the pentose phosphate pathway. The lack of enzymes responsible for the production of NADPH has a significant impact on yeast cells. However, cells may compensate in different ways for impairments in NADPH synthesis, and the choice of compensation strategy has several consequences for cell functioning. The present study of this issue was based on isogenic mutants: Δzwf1, Δgnd1, Δald6, and the wild strain, as well as a comprehensive panel of molecular analyses such as the level of gene expression, protein content, and enzyme activity. The obtained results indicate that yeast cells compensate for the lack of enzymes responsible for the production of cytosolic NADPH by changing the content of selected proteins and/or their enzymatic activity. In turn, the cellular strategy used to compensate for them may affect cellular efficiency, and thus, the ability to grow or sensitivity to environmental acidification. [ABSTRACT FROM AUTHOR]

Fungal colonization poses a significant risk for neonates, leading to invasive infections such as fungemia. While Candida species are the most commonly identified pathogens, other rare yeasts are increasingly reported, complicating diagnosis and treatment due to limited data on antifungal pharmacokinetics. These emerging yeasts, often opportunistic, underscore the critical need for early diagnosis and targeted therapy in neonates. This systematic review aims to comprehensively analyze all published cases of neonatal fungemia caused by rare opportunistic yeasts, examining geographical distribution, species involved, risk factors, treatment approaches, and outcomes. Searching two databases (PubMed and SCOPUS), 89 relevant studies with a total of 342 cases were identified in the 42-year period; 62% of the cases occurred in Asia. Pichia anomala (31%), Kodamaea ohmeri (16%) and Malassezia furfur (15%) dominated. Low birth weight, the use of central catheters, prematurity, and the use of antibiotics were the main risk factors (98%, 76%, 66%, and 65%, respectively). 22% of the cases had a fatal outcome (80% in Asia). The highest mortality rates were reported in Trichosporon beigelii and Trichosporon asahii cases, followed by Dirkmeia churashimamensis cases (80%, 71%, and 42% respectively). Low birth weight, the use of central catheters, the use of antibiotics, and prematurity were the main risk factors in fatal cases (84%, 74%, 70%, and 67%, respectively). 38% of the neonates received fluconazole for treatment but 46% of them, died. Moreover, the rare yeasts of this review showed high MICs to fluconazole and this should be taken into account when planning prophylactic or therapeutic strategies with this drug. In conclusion, neonatal fungemia by rare yeasts is a life-threatening and difficult-to-treat infection, often underestimated and misdiagnosed. [ABSTRACT FROM AUTHOR]

Aging is an inevitable biological process that contributes to the onset of age-related diseases, often as a result of mitochondrial dysfunction. Understanding the mechanisms behind aging is crucial for developing therapeutic interventions. This study investigates the effects of curcumin on postmitotic cellular lifespan (PoMiCL) during chronological aging in yeast, a widely used model for human postmitotic cellular aging. Our findings reveal that curcumin significantly prolongs the PoMiCL of wildtype yeast cells, with the most pronounced effects observed at lower concentrations, indicating a hormetic response. Importantly, curcumin also extends the lifespan of postmitotic cells with mitochondrial deficiencies, although the hormetic effect is absent in these defective cells. Mechanistically, curcumin inhibits TORC1 activity, enhances ATP levels, and induces oxidative stress. These results suggest that curcumin has the potential to modulate aging and offer therapeutic insights into age-related diseases, highlighting the importance of context in its effects. [ABSTRACT FROM AUTHOR]

Variants in membrane trafficking proteins are known to cause rare disorders with severe symptoms. The highly conserved transport protein particle (TRAPP) complexes are key membrane trafficking regulators that are also involved in autophagy. Pathogenic genetic variants in specific TRAPP subunits are linked to neurological disorders, muscular dystrophies, and skeletal dysplasias. Characterizing these variants and their phenotypes is important for understanding the general and specialized roles of TRAPP subunits as well as for patient diagnosis. Patient-derived cells are not always available, which poses a limitation for the study of these diseases. Therefore, other systems, like the yeast Saccharomyces cerevisiae, can be used to dissect the mechanisms at the intracellular level underlying these disorders. The development of CRISPR/Cas9 technology in yeast has enabled a scar-less editing method that creates an efficient humanized yeast model. In this study, core yeast subunits were humanized by replacing them with their human orthologs, and TRAPPC1, TRAPPC2, TRAPPC2L, TRAPPC6A, and TRAPPC6B were found to successfully replace their yeast counterparts. This system was used for studying the first reported individual with an autosomal recessive disorder caused by biallelic TRAPPC1 variants, a girl with a severe neurodevelopmental disorder and myopathy. We show that the maternal variant (TRAPPC1 p.(Val121Alafs*3)) is non-functional while the paternal variant (TRAPPC1 p.(His22_Lys24del)) is conditional-lethal and affects secretion and non-selective autophagy in yeast. This parallels defects seen in fibroblasts derived from this individual which also showed membrane trafficking defects and altered Golgi morphology, all of which were rescued in the human system by wild-type TRAPPC1. This study suggests that humanized yeast can be an efficient means to study TRAPP subunit variants in the absence of human cells and can assign significance to variants of unknown significance (VUS). This study lays the foundation for characterizing further TRAPP variants through this system, rapidly contributing to disease diagnosis. [ABSTRACT FROM AUTHOR]

Non-Saccharomyces yeasts have recently garnered significant interest in oenology. When co-inoculated with Saccharomyces cerevisiae, they contribute to the improvement of wine quality from a sensory point of view. In the present study, a group of yeasts previously isolated from manna and honey by-products were subjected to a genotypic identification. The D1/D2 variable domains of the 26-sRNA gene and the ITS region of the 5.8S gene were sequenced. Additionally, a differentiation of strains was carried out by RAPD-PCR. All strains underwent in vitro screening. Subsequently, a micro-vinification experiment was conducted, focusing on strains with favourable technological characteristics: Lachancea thermotolerans, Starmerella lactis-condensi, and Candida oleophila. These strains were sequentially inoculated alongside a control strain of Saccharomyces cerevisiae. Technological screening revealed that some strains exhibited limited H2S production, ethanol tolerance (up to 8% v/v), resistance to potassium metabisulphite (200 mg/L), osmotic stress tolerance (up to 320 g/L of glucose), and copper resistance (on average 5 mM). The findings from this study can guide the selection of new starters and co-starters for regional wine production. [ABSTRACT FROM AUTHOR]

Mead is a fermented alcoholic beverage produced from a diluted solution of honey and yeast activity. The objectives of this study were to produce a potentially probiotic mead through mixed fermentation by Saccharomyces cerevisiae var. boulardii and kombucha microorganisms and to evaluate fermentation kinetics, microbial cell survival and their in vitro resistance to simulated gastrointestinal transit, color parameters and the phenolic and antioxidant potential of the product. The main results of this study show that in order to develop a potentially probiotic mead utilizing the mixed fermentation of S. boulardii and kombucha microorganisms, the best condition was a concentration of 25 mL/L (v/v) of kombucha and 0.75 g/L (w/v) of S. boulardii with fermentation for 9 days at a temperature of 25 °C. In addition, at the end of fermentation, mead with kombucha and S. boulardii presented physicochemical characteristics with a pH of 3.48, 0.67% total acidity, 18.76 °Brix soluble solids and 4.77% alcohol content. The S. boulardii and lactic acid bacteria (LAB) present in the mead survived conditions reproducing those of the gastrointestinal tract, with counts of more than 6 Log10 CFU/mL for both microorganisms after the intestinal phase. In the color analysis, the mead with kombucha and S. boulardii had a yellow color with the b* parameter corresponding to 35.93, luminosity (L*) equal to 76.09 and 1.82 for a*. In addition, the mead we produced contains quantities of phenolics and antioxidants. In conclusion, kombucha and S. boulardii are presented as alternative microbial sources for obtaining potentially probiotic mead. [ABSTRACT FROM AUTHOR]

Yeasts play an essential role in the aroma and sensory profiles of wines. Spontaneous fermentations were carried out at the newly built winery of Granxa D'Outeiro. Yeasts were isolated from must at different stages of fermentation. Colonies belonging to Saccharomyces cerevisiae were characterised at the strain level by mtDNA-RFLPs. General chemical parameters and aroma profiles of the wines were determined using official OIV methodology and GC-MS analysis, respectively. The diversity of S. cerevisiae per fermentation ranged from 5 to 13 different strains depending on the grapevine variety. Out of 24 strains, strain B was the dominant yeast in most fermentations at different proportions, but strains D, E, and H also reached up to 25% of the total population in some fermentations. The yeast diversity was higher in the Lado fermentation than in those containing Treixadura. The chemical compositions of the wines revealed differences among them, with Loureira and Albariño wines showing the highest content of volatile compounds. The evaluation of their technological properties revealed the oenological potential of some strains of S. cerevisiae. The strains showing the best scores were selected to be used in future vintages to enhance the typicality of wines in the Granxa D'Outeiro winery. [ABSTRACT FROM AUTHOR]

To date, there are no specific guidelines for the use of bioacidifying yeasts in winemaking. In this work, we aimed to characterize an oenological strain of Lachancea thermotolerans (Lt), a non-Saccharomyces lactic acid-producing yeast, and to test different sequential inoculation conditions with Saccharomyces cerevisiae (Sc). The results of bench scale vinifications showed that both the strategy of inoculating Sc 12 h after Lt and the mixing of Lt and Sc during fermentation delivered an acceptable increase in lactic acid (2 g/L) and a decrease in pH (about 0.15 units). Therefore, both strategies were implemented in winery experiments. Our results at the cellar scale showed no increase in acidity, which was likely due to the presence of indigenous yeasts. Overall, our experience shows the difficulty of translating laboratory protocols into cellar experiments and calls for further research into new strategies for implementing acidifying yeasts. [ABSTRACT FROM AUTHOR]

Spoilage fungi are a significant cause of financial loss in the food and beverage industry each year. These fungi thrive in challenging environments characterized by low acidity, low water activity and high sugar content, all of which are common in fruit fillings used in pastry products. Fruit fillings are therefore highly susceptible to fungal spoilage. Fungal growth can cause sensory defects in foods, such as changes in appearance, odor, flavor or texture, and can pose health risks due to the production of mycotoxins by certain mold species. To reduce food loss and waste and extend product shelf-life, it is critical that we prevent fungal spoilage. Synthetic chemicals such as sorbic acid and potassium sorbate are commonly used as preservatives to prevent fungal spoilage. However, with consumer demand for 'natural' and 'chemical-free' foods, research into clean-label preservative alternatives to replace chemical preservatives has increased. The objectives of this review are (i) to provide an overview of the sources of fungal contamination in fruit filling production systems, from pre-harvest of raw materials to storage of the final product, and to identify key control factors; and (ii) to discuss preservation techniques (both conventional and novel) that can prevent fungal growth and extend the shelf-life of fruit fillings. [ABSTRACT FROM AUTHOR]

This study explored the enantiocomplementary bioreduction of substituted 1-(arylsulfanyl)propan-2-ones in batch mode using four wild-type yeast strains and two different recombinant alcohol dehydrogenases from Lactobacillus kefir and Rhodococcus aetherivorans. The selected yeast strains and recombinant alcohol dehydrogenases as whole-cell biocatalysts resulted in the corresponding 1-(arylsulfanyl)propan-2-ols with moderate to excellent conversions (60–99%) and high selectivities (ee > 95%). The best bioreductions—in terms of conversion (>90%) and enantiomeric excess (>99% ee)—at preparative scale resulted in the expected chiral alcohols with similar conversion and selectivity to the screening reactions. [ABSTRACT FROM AUTHOR]

Plant peptidase inhibitors play crucial roles in plant defence mechanisms and physiological processes. In this study, we isolated and characterised a Kunitz trypsin inhibitor from Enterolobium gummiferum seeds named EgPI (E. gummiferum peptidase inhibitor). The purification process involved two chromatography steps using size exclusion and hydrophobic resins, resulting in high purity and yield. EgPI appeared as a single band of ~20 kDa in SDS-PAGE. Under reducing conditions, the inhibitor exhibited two polypeptide chains, with 15 and 5 kDa. Functional characterisation revealed that EgPI displayed an inhibition stoichiometry of 1:1 against trypsin, with a dissociation constant of 8.4 × 10−9 mol·L−1. The amino-terminal sequencing of EgPI revealed the homology with Kunitz inhibitors. Circular dichroism analysis provided insights into the secondary structure of EgPI, which displayed the signature typical of Kunitz inhibitors. Stability studies demonstrated that EgPI maintained the secondary structure necessary to exhibit its inhibitory activity up to 70 °C and over a pH range from 2 to 8. Microbiological screening revealed that EgPI has antibiofilm properties against pathogenic yeasts at 1.125 μmol·L−1, and EgPI reduced C. albicans biofilm formation by 82.7%. The high affinity of EgPI for trypsin suggests potential applications in various fields. Furthermore, its antibiofilm properties recommended its usefulness in agriculture and antimicrobial therapy research, highlighting the practical implications of our research. [ABSTRACT FROM AUTHOR]

The fidelity of replication, especially in the presence of DNA damage, is essential for the proper function of cells. Mutations that inactivate genes involved in DNA damage repair or bypass are enriched in several types of cancer cells. Thus, it is important to further our understanding of the mechanisms governing replication fidelity. PCNA is a ring-shaped complex that encircles DNA at the front of the replication fork, at the double-stranded/single-stranded DNA junction. It serves as a processivity factor for the different DNA replication polymerases, allowing them to replicate longer stretches of DNA by physically tethering them to the DNA and preventing their detachment. In addition, PCNA also regulates and coordinates different DNA damage bypass pathways meant to allow DNA replication in the presence of DNA damage. Due to its essentiality and the numerous functions it has in the cell, much is still unclear about PCNA. Here, we utilize PCNA mutants that lower the stability of the PCNA complex on the chromatin, and thus tend to disassociate and fall from the DNA. Using these mutants, we show that PCNA's physical presence on the DNA can prevent DNA misalignment at repetitive sequences, leading to increased mutation formation. We also show that PCNA-interacting proteins play an important role in strengthening the ring's stability on the chromatin. Such repetitive sequence-induced mutations are common in several human diseases and it is important to study their formation and the mechanisms guarding against them. [ABSTRACT FROM AUTHOR]

Recombination hotspot-activating DNA sites (e.g., M26, CCAAT, Oligo-C) and their binding proteins (e.g., Atf1-Pcr1 heterodimer; Php2-Php3-Php5 complex, Rst2, Prdm9) regulate the distribution of Spo11 (Rec12)-initiated meiotic recombination. We sought to create 14 different candidate regulatory DNA sites via bp substitutions in the ade6 gene of Schizosaccharomyces pombe. We used a fission yeast-optimized CRISPR-Cas9 system (SpEDIT) and 196 bp-long dsDNA templates with centrally located bp substitutions designed to ablate the genomic PAM site, create specific 15 bp-long DNA sequences, and introduce a stop codon. After co-transformation with a plasmid that encoded both the guide RNA and Cas9 enzyme, about one-third of colonies had a phenotype diagnostic for DNA sequence changes at ade6. PCR diagnostics and DNA sequencing revealed a diverse collection of alterations at the target locus, including: (A) complete or (B) partial template-directed substitutions; (C) non-homologous end joinings; (D) duplications; (E) bp mutations, and (F) insertions of ectopic DNA. We concluded that SpEDIT can be used successfully to generate a diverse collection of DNA sequence elements within a reporter gene of interest. However, its utility is complicated by low efficiency, incomplete template-directed repair events, and undesired alterations to the target locus. [ABSTRACT FROM AUTHOR]

Onychomycosis (OM) is a widespread infection requiring prolonged treatment with potential side effects. Diagnostic certainty is therefore essential before initiating antifungal therapy. Molecular biology has already shown benefits in reducing the time to diagnosis, providing technical ease, and increasing sensitivity for the respective species that molecular tests can detect. Nevertheless, causative agents are numerous, and culture remains essential, particularly for detecting non-dermatophytes mold infections. This study compared the performance of three different diagnostic strategies: conventional culture technique, the multiplex DermaGenius® 2.0 PCR (DG), and a mixed PCR/culture algorithm guided by the result of direct examination with calcofluor (DEC). The mixed algorithm (MA) prioritizes DG PCR and DEC as the primary diagnostic tools, supplemented by selective sample inoculation when mycelial elements are visualized in DEC and when DG PCR fails to detect any fungus or identifies a fungus with morphology differing from that observed in DEC (filamentous fungi versus yeasts). With only 13% of samples requiring inoculation, MA emerged as the most effective strategy, demonstrating significantly higher sensitivity (98.18%; p < 0.001) compared to single-method approaches (78.18% for DG PCR alone and 74.55% for culture alone) while maintaining a specificity comparable to DG PCR (100%). This new approach saves time in result delivery, requires fewer human resources, and increases diagnostic accuracy to better meet the needs of clinicians. [ABSTRACT FROM AUTHOR]

In a scenario of accelerated global climate change, the continuous growth of the world population, and the excessive use of chemical fertiliser, the search for sustainable alternatives for agricultural production is crucial. The present study was conducted to evaluate the plant growth-promoting (PGP) characteristics of two yeast strains, Candida guilliermondii and Rhodotorula mucilaginosa, and the physicochemical characteristics of nanometric capsules and iron oxide nanoparticles (Fe2O3-NPs) for the formulation of nanobiofertilisers. The physiological and productive effects were evaluated in a greenhouse assay using lettuce plants. The results showed that C. guilliermondii exhibited higher tricalcium phosphate solubilisation capacity, and R. mucilaginosa had a greater indole-3-acetic acid (IAA) content. The encapsulation of C. guilliermondii in sodium alginate capsules significantly improved the growth, stomatal conductance, and photosynthetic rate of the lettuce plants. Physicochemical characterisation of the Fe2O3-NPs revealed a particle size of 304.1 nm and a negative Z-potential, which indicated their stability and suitability for agricultural applications. The incorporation of Fe2O3-NPs into the capsules was confirmed by SEM-EDX analysis, which showed the presence of Fe as the main element. In summary, this study highlights the potential of nanobiofertilisers containing yeast strains encapsulated in sodium alginate with Fe2O3-NPs to improve plant growth and photosynthetic efficiency as a path toward more sustainable agriculture. [ABSTRACT FROM AUTHOR]

Yeast plays a significant role in a variety of fields. In particular, it is extensively used as a model organism in genetics and cellular biology studies, and is employed in the production of vaccines, pharmaceuticals, and biofuels. Traditional "bulk"-based studies on yeast growth often overlook cellular variability, emphasizing the need for single-cell analysis. Micro-droplets, tiny liquid droplets with high surface-area-to-volume ratios, offer a promising platform for investigating single or a small number of cells, allowing precise control and monitoring of individual cell behaviors. Microfluidic devices, which facilitate the generation of micro-droplets, are advantageous due to their reduced volume requirements and ability to mimic in vivo micro-environments. This study introduces a custom-designed microfluidic device to encapsulate yeasts in micro-droplets under various conditions in a parallel manner. The results reveal that optimal glucose concentrations promoted yeast growth while cycloheximide and Cu2+ ions inhibited it. This platform enhances yeast cultivation strategies and holds potential for high-throughput single-cell investigations in more complex organisms. [ABSTRACT FROM AUTHOR]

This study presents the behavior of the identified yeast strain S. cerevisiae, isolated from Busuioacă de Bohotin grapes from the Pietroasa winery, during the process of fermentation to obtain dry active yeast biomass for the winemaking process. In this respect, we promoted an optimization strategy for obtaining active dry yeast biomass. The cultivation conditions for micropilot fermentation (temperature, pH, carbon source, and nitrogen source) were selected and designed according to a Taguchi design with four factors and three levels. Reproducibility testing was conducted under specific fermentation parameters: temperature (32 °C), pH (4.5), carbon source (12%), and nitrogen source (0.7%). Following the optimization process, two combinations of cultivation parameters were selected, and one of them, based on the results, was selected for further analysis. Quantitative data were obtained, showing dry yeast biomass (DCW) at 1.39 g/100 mL and protein content at 45.57%. The active yeast was then used in the winemaking process for Tămâioasă Românească and Busuioacă de Bohotin varieties at Pietroasa winery for validation. This optimization aims to facilitate easy and rapid production of fresh wine yeast tailored to the local winemaking practices of Pietroasa winery, with real application potential in other viticultural areas, aligning with the terroir concept. [ABSTRACT FROM AUTHOR]

Spirulina is a highly nutritious microalgae commonly used as a food additive. During fermentation, different adjuncts are incorporated to act as a nutrient source for yeast and fortify or modify the sensory attributes of the final product. In this study, the effect of Spirulina on the characteristics of controlled yeast fermentation and the production of volatile organic compounds (VOCs) was analyzed. Spirulina was added to malted barley during mashing and fermented under standard conditions. An unaltered mash (negative control) and yeast extract (positive control) were also fermented. The addition of Spirulina resulted in an increased fermentation rate (~14% faster) and bigger yeast cells (~34% larger) in comparison to the negative control. There were differences in color (determined as SRM) between treatments; however, there were only minor differences in VOCs, with no statistical differences observed between chemical compound groups. No differences were observed in the pH, total number of yeast cells, or final attenuation between treatments. The primary mechanism for the observed differences is believed to be an increase in amino acids available to yeast that were contributed by the Spirulina. This shows both that Spirulina has a high potential as a fermentation adjunct and that the amino acid profile of an adjunct can significantly impact fermentation. [ABSTRACT FROM AUTHOR]

Sourdough is one of the oldest technologies employed by humans to leaven bread because of its ability to enhance the flavour and structure of bread using micro-organisms. However, there is a lack of comprehensive information in Botswana regarding the diversity of sourdough starters and the fermentative micro-organisms responsible for spontaneous fermentation. The present study aimed to explore the microbial species diversity of sourdoughs in Botswana and gain insight into the unique microbial communities involved in sourdough production. A total of nine samples were collected from different areas in Botswana. The microbial diversity in sourdoughs was characterized through the sequencing of amplicons of the 16S ribosomal DNA and internal transcribed spacer regions. In silico polymerase chain reaction–restriction fragment length polymorphism and phylogenetics were utilized to determine the genetic diversity among the isolates. The dominant yeast species identified were Saccharomyces cerevisiae, Wickerhamomyces anomamlus, Pichia kudriazverii and kazachstania humilis. Additionally, the presence of Lactiplantibacillus plantarum, Lacticaseibacillus paracasei, Liquorilactobacillus nageli and Bacillus cereus was also detected. It is worth noting that two species of acetic acid bacteria (AAB), namely Acetobacter pasteurianus and A. indonesiensis, were isolated, though in low levels, but the finding is significant in sourdough fermentation. The low occurrence of AAB (acetic acid bacteria) species observed in this study could be an important finding, as these bacteria are considered understudied, yet they are known to contribute significantly to the final product. [ABSTRACT FROM AUTHOR]