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Translation fidelity relies on accurate aminoacylation of transfer RNAs (tRNAs) by aminoacyl-tRNA synthetases (AARSs). AARSs specific for alanine (Ala), leucine (Leu), serine, and pyrrolysine do not recognize the anticodon bases. Single nucleotide anticodon variants in their cognate tRNAs can lead to mistranslation. Human genomes include both rare and more common mistranslating tRNA variants. We investigated three rare human tRNALeu variants that mis-incorporate Leu at phenylalanine or tryptophan codons. Expression of each tRNALeu anticodon variant in neuroblastoma cells caused defects in fluorescent protein production without significantly increased cytotoxicity under normal conditions or in the context of proteasome inhibition. Using tRNA sequencing and mass spectrometry we confirmed that each tRNALeu variant was expressed and generated mistranslation with Leu. To probe the flexibility of the entire genetic code towards Leu mis-incorporation, we created 64 yeast strains to express all possible tRNALeu anticodon variants in a doxycycline-inducible system. While some variants showed mild or no growth defects, many anticodon variants, enriched with G/C at positions 35 and 36, including those replacing Leu for proline, arginine, alanine, or glycine, caused dramatic reductions in growth. Differential phenotypic defects were observed for tRNALeu mutants with synonymous anticodons and for different tRNALeu isoacceptors with the same anticodon. A comparison to tRNAAla anticodon variants demonstrates that Ala mis-incorporation is more tolerable than Leu at nearly every codon. The data show that the nature of the amino acid substitution, the tRNA gene, and the anticodon are each important factors that influence the ability of cells to tolerate mistranslating tRNAs.

The copper reductase activity of histone H3 suggests undiscovered characteristics within the protein. Here, we investigated the function of leucine 126 (H3L126), which occupies an axial position relative to the copper binding. Typically found as methionine or leucine in copper-binding proteins, the axial ligand influences the reduction potential of the bound ion, modulating its tendency to accept or yield electrons. We found that mutation of H3L126 to methionine (H3L126M) enhanced the enzymatic activity of native yeast nucleosomes in vitro and increased intracellular levels of Cu1+, leading to improved copper-dependent activities including mitochondrial respiration and growth in oxidative media with low copper. Conversely, H3L126 to histidine (H3L126H) mutation decreased nucleosome's enzymatic activity and adversely affected copper-dependent activities in vivo. Our findings demonstrate that H3L126 fine-tunes the copper reductase activity of nucleosomes and highlights the utility of nucleosome enzymatic activity as a novel paradigm to uncover previously unnoticed features of histones.

The Alliance of Genome Resources (Alliance) is an extensible coalition of knowledge bases focused on the genetics and genomics of intensively studied model organisms. The Alliance is organized as individual knowledge centers with strong connections to their research communities and a centralized software infrastructure, discussed here. Model organisms currently represented in the Alliance are budding yeast, Caenorhabditis elegans, Drosophila, zebrafish, frog, laboratory mouse, laboratory rat, and the Gene Ontology Consortium. The project is in a rapid development phase to harmonize knowledge, store it, analyze it, and present it to the community through a web portal, direct downloads, and application programming interfaces (APIs). Here, we focus on developments over the last 2 years. Specifically, we added and enhanced tools for browsing the genome (JBrowse), downloading sequences, mining complex data (AllianceMine), visualizing pathways, full-text searching of the literature (Textpresso), and sequence similarity searching (SequenceServer). We enhanced existing interactive data tables and added an interactive table of paralogs to complement our representation of orthology. To support individual model organism communities, we implemented species-specific landing pages and will add disease-specific portals soon; in addition, we support a common community forum implemented in Discourse software. We describe our progress toward a central persistent database to support curation, the data modeling that underpins harmonization, and progress toward a state-of-the-art literature curation system with integrated artificial intelligence and machine learning (AI/ML).

Small-molecule control of gene expression underlies the function of numerous engineered gene circuits that are capable of environmental sensing, computation, and memory. While many recently developed inducible promoters have been tailor-made for bacteria or mammalian cells, relatively few new systems have been built for Saccharomyces cerevisiae, limiting the scale of synthetic biology work that can be done in yeast. To address this, we created the yeast Tunable Expression Systems Toolkit (yTEST), which contains a set of five extensively characterized inducible promoter systems regulated by the small-molecules doxycycline (Dox), abscisic acid (ABA), danoprevir (DNV), 1-naphthaleneacetic acid (NAA), and 5-phenyl-indole-3-acetic acid (5-Ph-IAA). Assembly was made to be compatible with the modular cloning yeast toolkit (MoClo-YTK) to enhance the ease of use and provide a framework to benchmark and standardize each system. Using this approach, we built multiple systems with maximal expression levels greater than those of the strong constitutive TDH3 promoter. Furthermore, each of the five classes of systems could be induced at least 60-fold after a 6 h induction and the highest fold change observed was approximately 300. Thus, yTEST provides a reliable, diverse, and customizable set of inducible promoters to modulate gene expression in yeast for applications in synthetic biology, metabolic engineering, and basic research.

The extensive utilization of pesticides in agriculture has resulted in the presence of pesticide residues in food and feed, which poses a significant threat to human health. Various physical and chemical methods have been proposed to remove pesticides, but most of these methods are either costly or susceptible to secondary contamination. Consequently, the utilization of microorganisms, such as probiotics, for eliminating pesticides, has emerged as a promising alternative. Probiotics, including lactic acid bacteria, yeasts, and fungi, have demonstrated remarkable efficiency and convenience in eliminating pesticide residues from food or feed. To promote the application of probiotic decontamination, this review examines the current research status on the utilization of probiotics for pesticide reduction. The mechanisms involved in microbial decontamination are discussed, along with the toxicity and potential health risks of degradation products. Furthermore, the review explores strategies to enhance probiotic detoxification and outlines prospects for future development. [ABSTRACT FROM AUTHOR]

Yeasts are attractive hosts for the production of heterologous products due to their genetic tractability and relative ease of growth. While the baker's yeast Saccharomyces cerevisiae is a powerful workhorse of the biotechnology industry, the species has metabolic limitations and it is critical that we develop alternative platforms that will facilitate the development of bioprocesses that rely on sustainable feedstocks. In this study, we used synthetic biology tools to construct coumaric acid–producing strains of Kluyveromyces marxianus, a yeast whose physiological traits render it attractive for biotechnology applications. Coumaric acid is a building block in the synthesis of many different families of aromatics and is a key precursor for the synthesis of complect phenylpropanoid molecules, including many flavours and aromas. The starting point for this work was a K. marxianus chassis strain that has increased flux towards the synthesis of tyrosine and phenylalanine, the aromatic amino acids that can serve as starting points for coumaric acid synthesis. Following principles of synthetic biology, a modular approach was taken to identify the best solution to different metabolic possibilities and these were then combined in different ways. For the first step, it was established that the route from phenylalanine was superior to that from tyrosine and the combined overexpression of PlPAL , AtC4H and AtCPR1 delivered the highest yield of coumaric acid. Next, it was established that while Pdc5 and Aro10 both had phenylpyruvate decarboxylase activity, inactivation of ARO10 was sufficient to prevent flux loss in the pathway. Since phenylalanine is the starting point, efforts were made to improve efficiency of its production. It was found that glutamate was a preferred nitrogen source for coumaric acid production, and this knowledge was used to engineer a strain that overexpressed S. cerevisiae GDH1 and delivered higher yields of coumaric acid. Ultimately, this strategy led to the development of strains that has yields of up to 48 mg coumaric acid /g glucose. Strains were evaluated in bioreactors to investigate the effects of different process parameters. These analyses indicated that engineered strains face some redox balance challenges and further work will be required overcome these to develop strains that can perform well under industrial conditions. • The yeast Kluyveromyces marxianus was engineered to produce the aromatic precursor molecule coumaric acid. • The highest yield obtained was 48 mg coumaric acid per g glucose. • Engineering the GS/GOGAT pathway to increase intracellular glutamate increased coumaric acid titres. [ABSTRACT FROM AUTHOR]

β-glucans have garnered significant attention due to their numerous health-promoting and prebiotic attributes. β-glucans, a group of bioactive substance, are known to have biological effects such as immune-modulating, anti-inflammatory, anti-cancer, anti-senescence, hypoglycemic and hypocholesterolemic properties. Owing to its unique physical characteristics including its solubility, viscosity and gelation, the food industry and other sectors have witnessed a rise in the utilization of β-glucan. This study aims to present an overview of β-glucan manufacturing technologies, including extraction, isolation, and purification methods from different sources, comprising of bacteria, fungi and plants such as cereals, with the intention of enhancing these techniques for more productive manufacturing procedures. Additionally, β-glucans' physical characteristics, chemical alterations, prospective industrial uses, and future application prospects in food, pharmaceuticals, cosmetics, and other potentially value-added product are outlined research suggest that β-glucans will become more significant in the global food and health sectors in the future. [Display omitted] • β-glucans exhibit notable structural variations according to their origins. • Glucans are classified as α and β glucans based on the interchain linkage. • The capacity and mode of water retention of β-glucans are influenced by several factors. [ABSTRACT FROM AUTHOR]

Background: The yeast Saccharomyces cerevisiae, commonly used in industry, exhibits complex metabolism due to the Crabtree effect, fermenting alcohol even under aerobic conditions when glucose exceeds 0.10-0.15 g/L. The heat released by the biological activity is a signal very easy to collect, given the minimal instrumentation requirements. However, this heat depends on the activated metabolic pathways and provides only an indirect indicator, that cannot be used in a simple way. This study demonstrated the potential of a mechanistic model to control the process by measuring the heat released by the biological activity. Results: The complexity arising from coexisting metabolic pathways was addressed by a comprehensive model of Saccharomyces cerevisiae together with the heat of reaction included in a rigorous enthalpy balance of the bioreactor. Batch cultures were performed in an insulated bioreactor to trigger a temperature signal. The heat of individual metabolic pathways was determined by inverse analysis of these tests using Particle Swarm Optimization (PSO): -101.28 ±0.02kJ/mol for anaerobic fermentation, -231.27±0.06kJ/mol for aerobic fermentation, and -662.94 ± 0.54kJ/mol for ethanol respiration. Finally, the model was successfully applied and validated for online training under different operating conditions. Conclusions: The model demonstrates remarkable accuracy, with a mean relative error under 0.38% in temperature predictions for both anaerobic and aerobic conditions. The viscous dissipation is a key parameter specific to the bioreactor and the growth conditions. However, we demonstrated that this parameter could be fitted accurately from the early stages of the experiment for further prediction of the remaining part. This model introduces temperature, or the thermal power required to maintain temperature, as a measurable parameter for online feedback model training to provide increasingly precise feed-forward control. [ABSTRACT FROM AUTHOR]

Malassezia furfur is a yeast known as the etiological agent of seborrheic dermatitis. We evaluated the action of five different antimicrobials (amphotericin B, chloramphenicol, ketoconazole, fluconazole, and nystatin) on inhibiting biofilm formation and removing biofilm already formed by M. furfur. The assays were carried out using the microdilution method, and scanning electron microscopy images were used to analyze the biofilm structure. According to the results obtained, the percentage of inhibition was higher for chloramphenicol, followed by ketoconazole, nystatin, and amphotericin B. Regarding the eradication of the biofilm formed, the highest percentage was chloramphenicol, followed by ketoconazole and nystatin. Amphotericin B did not affect biofilm eradication, whereas fluconazole did not cause significant changes inhibiting or removing M. furfur biofilm. Therefore, except for fluconazole, all evaluated antimicrobials had inhibiting effects on the biofilm of M. furfur, either in its formation and/or eradication. Although the results achieved with chloramphenicol have been highlighted, further in vitro and in vivo studies are still needed in order to include this antimicrobial in the therapy of seborrheic dermatitis due to its toxicity, especially to the bone marrow. [ABSTRACT FROM AUTHOR]

As an important cell factory, industrial yeast has been widely used for the production of compounds ranging from bulk chemicals to complex natural products. However, various adverse conditions including toxic products, extreme pH, and hyperosmosis etc., severely restrict microbial growth and metabolic performance, limiting the fermentation efficiency and diminishing its competitiveness. Therefore, enhancing the tolerance and robustness of yeasts is critical to ensure reliable and sustainable production of metabolites in complex industrial production processes. In this review, we provide a comprehensive review of various strategies for improving the tolerance of yeast cells, including random mutagenesis, system metabolic engineering, and material-mediated immobilization cell technology. It is expected that this review will provide a new perspective to realize the response and intelligent regulation of yeast cells to environmental stresses. [ABSTRACT FROM AUTHOR]

Karst aquifers are a significant source of drinking water and highly vulnerable to pollution and microbial contamination. Microbiological regulations for the quality of drinking water mostly focus on bacterial levels and lack guidance concerning fungal contamination. Moreover, there is no standardised microbial analysis methodology for identifying fungi in water. Our main objective was to establish the most effective culture and identification methodology to examine yeast diversity in karst waters. We assessed the comparative efficacy of four culture media (CHROMagar Candida, dichloran glycerol 18% [DG18], dichloran rose Bengal chloramphenicol [DRBC], and SYMPHONY agar) for yeast isolation from karst water samples. Furthermore, we investigated the comprehensiveness of databases used in MALDI-TOF mass spectrometry (MALDI-TOF MS) for identifying environmental yeast species. In total, we analysed 162 water samples, allowing the identification of 2479 yeast isolates. We demonstrate that a combination of four culture media, each with distinct specifications, more efficiently covers a wide range of yeast species in karst water than a combination of only two or three. Supplementation of a MALDI-TOF MS database is also critical for analysing environmental microbial samples and improved the identification of yeast biodiversity. This study is an initial step towards standardising the analysis of fungal biodiversity in karst waters, enabling a better understanding of the significance of this environmental reservoir in relation to public health. [ABSTRACT FROM AUTHOR]

The present study investigates the species boundaries, evolutionary relationships, and host-parasite interfaces of dimorphic mycoparasites that were previously assigned to Achroomyces soranus, Occultifur internus, and Platygloea mycophila based on morphological similarities. Our comparison of recently collected and cultivated samples with the type specimens of A. soranus and P. mycophila shows that both groups are species complexes, of which the taxa can be differentiated based on morphological and ecological characters. By integrating the results of a seven-locus dataset (SSU, LSU, ITS, RPB1, RPB2, TEF1, and mitochondrial CYT-B) and detailed micromorphological comparisons of the investigated specimens, we show for the first time that these three groups of mycoparasites belong to Cystobasidiomycetes (Pucciniomycotina). We applied a polyphasic species concept involving morphology, phylogeny, and ecology to delineate and circumscribe these and new genera. The genus Occultifur comprises six species. Occultifur internus and the newly proposed O. cerinomycicola are intrahymenial mycoparasites producing haustorial cells and establishing fusion pore interaction with their Dacrymycetous host. Based on microscopical examination, we show that Achroomyces soranus is a member of the genus Occultifur. Based on the molecular phylogenetic reconstruction, we found that three lichen-associated fungi which are only known from a yeast morph are nested within Occultifur, i.e. Lichenozyma pisutiana, Microsporomyces cladoniae, and M. wangii. The genus Obvidator is newly introduced for three mycoparasitic species inhabiting members of the corticioid genus Peniophora (Russulales, Agaricomycetes) and causing gall-like malformations of the host basidiome. Microscopic investigation shows that Platygloea mycophila is a member of this genus. Obvidator species display a yet undiscovered type of host-parasite interface, in which the mycoparasites produce short protrusions on their hyphae adjacent to the host hyphae. The lysis of the host cell wall takes place at points of contact with parasite protrusions, but no rupture of the host plasma membrane or nanometer-fusion pore formation was observed. The updated Cystobasidiomycetes phylogeny obtained in this study by including mycoparasites showed that the genera Occultifur and Microsporomyces as currently circumscribed are polyphyletic. To resolve this polyphyly, we introduce two new genera, i.e. Cystastrum and Millanizyma, and recombine species comprising the Occultifur externus clade and a clade consisting of Microsporomyces bloemfonteinensis and M. cladoniophilus, respectively. [ABSTRACT FROM AUTHOR]

Consumers have increasingly favoured fermented drinks due to their high content of probiotic secondary metabolites. These beverages are believed to possess the capacity to safeguard against non-communicable ailments such as coronary heart disease, cancer, diabetes, antimicrobial infections, and other dietary-related disorders. Lemongrass (Cymbopogon citratus) is a commonly used botanical ingredient in therapeutic tea production. It is renowned for its highly valuable essential oil, which has significant commercial demand. This study examines the functional content and antioxidant effects of fermented beverages derived from lemongrass. We employed the yeast Saccharomyces cerevisiae to carry out the fermentation process on the lemongrass compositions, extending the duration from t = 24 to t = 96 h. We used non-fermented samples as control. This investigation identified numerous active biomolecules and polyphenols in the fermented samples, including flavonoids, tannins, cardiac glycosides, coumarins, terpenoids, steroids, saponins, and reducing sugars. After t = 24 h fermentation, the radical-scavenging activity reached its maximum level of 89.1%, and the antioxidant content reached 13.06 µg/ml, which is equivalent to the amount of ascorbic acid. After t = 36 h fermentation, the total phenolic content reached a concentration of 237.19 µg/ml, while the flavonoid content reached its peak at 55.21 µg/ml after t = 72 h fermentation. Lemongrass fermentation exhibits a wide range of phytochemicals and bioactive components that effectively eliminate free radicals, despite the antioxidant content fluctuation throughout the fermentation period of t = 24 to t = 96 h. [ABSTRACT FROM AUTHOR]

In view of the special aptitudes of the yeast population in both rice wine production and dough fermentation, in this study, the characteristics of dough fermented with rice wine prepared from mixed Saccharomycopsis fibuligera SF7 and Saccharomyces cerevisiae SC1 (JFC) were evaluated and compared with those of dough fermented directly with the two yeast co-cultures (FC). Dough inoculated with JFC showed higher acidity, reducing sugar content and leavening activity than dough fermented with FC. The water distribution pattern and pasting properties of the JFC-fermented dough changed dramatically after fermentation, and the dough microstructure and extensibility were improved. The steamed bread made with JFC-fermented dough had improved specific volume and showed similar volatile compound profiles to that made with commercial Jiuqu. These results indicated that mixed S. fibuligera SF7 and S. cerevisiae SC1 could be used as defined starter cultures in rice wine preparation for steamed bread production. [ABSTRACT FROM AUTHOR]

This study is aimed at investigating the possibility of using spent cells of brewer's yeast Saccharomyces cerevisiae to encapsulate the plant antioxidant curcumin and the effect of such an approach on the bioavailability of BAS in an in vitro digestion model. Spent brewer's yeast is a significant volume organic waste that is difficult to dispose of, which makes additional options for its use very promising. Encapsulation of curcumin into spent yeast cells was carried out in a nanostructured manner. The encapsulation process was studied using laser dynamic light scattering, inverted and luminescence microscopy, and FTIR analysis. The efficiency and feasibility of curcumin encapsulation process was evaluated by determining the encapsulation efficiency index and modeling the in vitro digestion process. From these studies, it was found that spent yeast cells are capable of acting as a "delivery system" for curcumin. Encapsulation efficiencies of 47.7% can be achieved if curcumin is prenanostructured. Analysis of the potential bioavailability of the plant antioxidant in an in vitro gastric digestion model showed that the technology of encapsulation into yeast cells allows for curcumin retention of 79.5%. [ABSTRACT FROM AUTHOR]

Wastewater from many food and beverage manufacturers is enriched in organic content, and it must therefore be treated before being discharged to comply with the strict environmental regulations to protect the final water quality. Concretely, the honey processing wastewater, that remains in holding tanks until is disposal, is a rich source of sugars and this high level of organic material will degrade the water quality if not treated properly provoking an imbalance in the ecosystem. There are different strategies for an adequate treatment of this wastewater effluent to obtain a sustainable usage. One of the techniques that is more cost-effective and environmental friendlier than chemical procedures used for water remediation, is the use of microorganisms (including algae, fungi, yeasts, or bacteria). Given that they are fast-growing, robust, and metabolically diverse, yeast strains are often used for wastewater treatment. In this work, we have studied the potential for bioremediation of non Saccharomyces yeast isolated from a honey processing wastewater generated by an Argentine exporting company. The inoculation of these yeast strains to the existing flora in the honey wastewater yielded a better improvement in the treatment yield. These results suggest that these strains display a promising role could for optimizing bioremediation strategies in industrial wastewater treatment processes. [ABSTRACT FROM AUTHOR]

Copyright of Food & Fermentation Industries is the property of Food & Fermentation Industries and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Food & Fermentation Industries is the property of Food & Fermentation Industries and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

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]

Copyright of Food Research & Development is the property of Food Research & Development Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Protein-rich diets shorten lifespan but increase fecundity in many organisms. Animals actively adjust their feeding behavior to meet their nutritional requirements. However, the neural mechanisms underlying the dynamic regulation of protein consumption remain unclear. Here we find that both sexes of fruit flies exhibit a preference for protein food before mating to prepare for reproduction. Mated female flies display an increased appetite for yeast to benefit their offspring, albeit at the cost of stress resistance and lifespan. In contrast, males show a momentarily reduced yeast appetite after mating likely to restore their fitness. This mating state-dependent switch between sexes is mediated by a sexually dimorphic neural circuit labeled with leucokinin in the anterior brain. Furthermore, intermittent yeast consumption benefits both the lifespan and fecundity of males, while maximizing female fecundity without compromising lifespan. Protein-rich diets are known to enhance fecundity but often reduce lifespan across various species. Here, the authors demonstrate that fruit flies undergo a sex-specific post-mating dietary shift that balances fecundity with overall fitness, regulated by leucokinin-labeled neural circuits. [ABSTRACT FROM AUTHOR]

Loss of cytosolic actin filaments upon TORC2 inhibition triggers chromosome fragmentation in yeast, which results from altered base excision repair of Zeocin-induced lesions. To find the link between TORC2 kinase and this yeast chromosome shattering (YCS) we performed phosphoproteomics. YCS-relevant phospho-targets included plasma membrane-associated regulators of actin polymerization, such as Las17, the yeast Wiscott-Aldrich Syndrome protein. Induced degradation of Las17 was sufficient to trigger YCS in presence of Zeocin, bypassing TORC2 inhibition. In yeast, Las17 does not act directly at damage, but instead its loss, like TORC2 inhibition, raises nuclear actin levels. Nuclear actin, in complex with Arp4, forms an essential subunit of several nucleosome remodeler complexes, including INO80C, which facilitates DNA polymerase elongation. Here we show that the genetic ablation of INO80C activity leads to partial YCS resistance, suggesting that elevated levels of nuclear G-actin may stimulate INO80C to increase DNA polymerase processivity and convert single-strand lesions into double-strand breaks. Here the authors reveal that TORC2 inhibition and the rapid degradation of Las17/WASP elevates G-actin levels in the yeast nucleus which are responsible for altered long-patch base excision repair of clustered lesions, generating massive chromosome fragmentation. [ABSTRACT FROM AUTHOR]

Introduction: Safflower, a traditional Chinese medicine, is rich in chemical components including flavonoids, polysaccharides, and alkaloids. It exhibits pharmacological effects such as antioxidant, anti-inflammatory, anti-tumor, and anti-thrombosis properties, making it a valuable resource in the medical field. Furthermore, due to its antioxidant and anti-inflammatory effects, safflower is increasingly being utilized in the cosmetics industry. Methods: In this study, yeast was employed to ferment safflower, and the optimal fermentation conditions were established through single-factor experiments and response surface methodology. Subsequently, the antioxidant and anti-inflammatory efficacy of the safflower fermentation solution was assessed using both cellular and zebrafish models. Finally, the safety of the safflower fermentation solution was evaluated through a cosmetic eye irritation test. Results: From a total of 20 yeast strains, YF-5 was identified as the dominant strain for safflower fermentation. By optimizing the fermentation conditions, it was established that the optimal parameters for YF-5 fermentation of safflower are as follows: a fermentation temperature of 36.55°C, a material-to-liquid ratio of 1:20.46, a fructose concentration of 6.20%, a fermentation duration of 72 h, and an inoculum volume of 4%. The biological activities of safflower, including its antioxidant and anti-inflammatory properties, were enhanced through yeast fermentation. In HaCaT cell and zebrafish oxidative damage assays, safflower fermentation solution inhibits the production of malondialdehyde (MDA) and increases superoxide dismutase (SOD) activity as well as total antioxidant capacity (T-AOC). In the RAW264.7 cell inflammatory damage assays, a 20% safflower fermentation solution was found to inhibit the release of TNF-α and NO in the inflammatory model, with inhibition rates of 30.94 and 28.86%, respectively. In the zebrafish inflammatory damage assays, the quantity of fluorescent neutral proteins in the 5% safflower fermentation solution was 0.7 times that observed in the dexamethasone (0.1 mg/mL) positive control group, indicating that its anti-inflammatory activity is comparable to that of dexamethasone (0.1 mg/mL). In the chicken embryo chorionic membrane experiment, it was observed that the safflower fermentation solution did not cause significant damage to the blood vessels of the chorionic allantoic membrane (CAM). This finding demonstrates that the safflower fermentation solution possesses a certain degree of safety. Discussion: Safflower fermentation solution has antioxidant and anti-inflammatory bioactivities, and it has passed cosmetic safety evaluations. It can be used as a new natural cosmetic ingredient added to cosmetic products. [ABSTRACT FROM AUTHOR]

Saccharomyces cerevisiae L7 was found to be an excellent starter and biological deacidification strain for Suanyu, however, the underlying mechanisms remain poorly understood. This study aimed to investigate the acid inhibition mechanism of S. cerevisiae L7. The strain enhances the sensory and flavor characteristics of Suanyu. The growth of Lactiplantibacillus plantarum is inhibited due to competition for carbon sources, resulting in a decrease in cell count from 9.00 Lg CFU/mL at 48 h to 7.70 Lg CFU/mL in co-culture. The addition of yeast reduces acidity, decreasing it from 5.83 g/kg to 0.82 g/kg at 48 h, while increasing sugar utilization to 94.52%. We found that cell contact was the main method of inhibition between the two microbials. Transcriptome analysis revealed that multiple pathways were affected under co-culture, ultimately leading to a decrease in lactic acid production. These findings provide valuable insights into the microbial interactions involved in biological deacidification. [ABSTRACT FROM AUTHOR]

Domestication can be understood as a symbiotic relationship that benefits both domesticator and domesticated species, involving multiple genetic changes that configure the phenotype of the domesticated species. One of the most important domesticated species is the yeast Saccharomyces cerevisiae, with both domesticated strains used for different fermentations processes for thousands of years and wild strains existing only in environments without human intervention; however, little is known about the phenotypic effects associated with its domestication. In the present work, we studied the effect of domestication on yeast TORC1 activation, a pleiotropic signalling pathway conserved across the eukaryotic domain. To achieve this goal, we improved a previously generated methodology to assess TORC1 activation, which turned out to be as effective as the original one but also presents several practical advantages for its application (such as facilitating confirmation of transformants and putting the Luc reporter gene under the control of the same PRPL26A promoter for each transformed strain). We then generated a mapping population, the so-called TOMAN-G population, derived from the "1002 Yeast Genomes Project" population, the most comprehensive catalogue of the genetic variation in yeasts. Finally, strains belonging to the TOMAN-G population were phenotyped for TORC1 activation, and then we compared the results obtained between yeast strains with different ecological origins, finding differences in TORC1 activation between wild and domesticated strains, particularly wine strains. These results are indicative of the effect of domestication on TORC1 activation, specifically that the different evolutionary trajectories of wild and domesticated strains have in fact caused differences in the activation of this pathway; furthermore, the phenotypic data obtained in this work could be used to continue underlying the genetic bases of TORC1 activation, a process that is still not fully understood, using techniques such as GWAS to search for specific genetic variants underlying the observed phenotypic variability and phylogenetic tree inferences to gain insight into the evolutionary relationships between these genetic variants. [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]

Vesicles bud from maturing Golgi cisternae in a programmed sequence. Budding is mediated by adaptors that recruit cargoes and facilitate vesicle biogenesis. In Saccharomyces cerevisiae, the AP-3 adaptor complex directs cargoes from the Golgi to the lysosomal vacuole. The AP-3 core consists of small and medium subunits complexed with two non-identical large subunits, ß3 (Apl6) and d (Apl5). The C-termini of ß3 and d were thought to be flexible hinges linking the core to ear domains that bind accessory proteins involved in vesicular transport. We found by computational modeling that the yeast ß3 and d hinges are intrinsically disordered and lack folded ear domains. When either hinge is truncated, AP-3 is recruited to the Golgi, but vesicle budding is impaired and cargoes normally sorted into the AP-3 pathway are mistargeted. This budding deficiency causes AP-3 to accumulate on ring-like Golgi structures adjacent to GGA adaptors that, in wild-type cells, bud vesicles downstream of AP-3 during Golgi maturation. Thus, each of the disordered hinges of yeast AP-3 has a crucial role in mediating transport vesicle formation at the Golgi. [ABSTRACT FROM AUTHOR]

The mRNA 5'-cap structure removal by the decapping enzyme DCP2 is a critical step in gene regulation. While DCP2 is the catalytic subunit in the decapping complex, its activity is strongly enhanced by multiple factors, particularly DCP1, which is the major activator in yeast. However, the precise role of DCP1 in metazoans has yet to be fully elucidated. Moreover, in humans, the specific biological functions of the two DCP1 paralogs, DCP1a and DCP1b, remain largely unknown. To investigate the role of human DCP1, we generated cell lines that were deficient in DCP1a, DCP1b, or both to evaluate the importance of DCP1 in the decapping machinery. Our results highlight the importance of human DCP1 in decapping process and show that the EVH1 domain of DCP1 enhances the mRNA-binding affinity of DCP2. Transcriptome and metabolome analyses outline the distinct functions of DCP1a and DCP1b in human cells, regulating specific endogenous mRNA targets and biological processes. Overall, our findings provide insights into the molecular mechanism of human DCP1 in mRNA decapping and shed light on the distinct functions of its paralogs. [ABSTRACT FROM AUTHOR]

Microbial fermentations are widely used for the production of chemicals used as pharmaceuticals, food ingredients, materials, solvents, and biofuels. Technoeconomic analysis of a given fermentation process is important to perform before scaling the process to levels that enable commercial production. Titer, rate, and yield (TRY) of the fermentation process are key metrics that are used for technoeconomic analysis. TRY metrics have different impacts on the technoeconomic analysis, and it is important to be aware of these differences. Microbial fermentations offer the opportunity to produce a wide range of chemicals in a sustainable fashion, but it is important to carefully evaluate the production costs. This can be done on the basis of evaluation of the titer, rate, and yield (TRY) of the fermentation process. Here we describe how the three TRY metrics impact the technoeconomics of a microbial fermentation process, and we illustrate the use of these for evaluation of different processes in the production of two commodity chemicals, 1,3-propanediol (PDO) and ethanol, as well as for the fine chemical penicillin. On the basis of our discussions, we provide some recommendations on how the TRY metrics should be reported when new processes are described. [ABSTRACT FROM AUTHOR]

Omega fatty acids are important for human health. They are traditionally extracted from animals or plants but can be alternatively produced using oleaginous yeast. Current efforts are producing yeast strains with similar fatty acid distributions and powerful lipogenesis capacity. The next step is to further make the process more competitive. [ABSTRACT FROM AUTHOR]

During DNA replication, core histones that form nucleosomes on template strands are evicted and associate with newly synthesized strands to reform nucleosomes. Mcm2, a subunit of the Mcm2-7 complex, which is a core component of the replicative helicase, interacts with histones in the amino-terminal region (Mcm2N) and is involved in the parental histone recycling to lagging strands. Herein, the interaction of Mcm2N with histones was biochemically analyzed to reveal the molecular mechanisms underlying histone recycling by Mcm2N. With the addition of Mcm2N, a histone hexamer, comprising an H3-H4 tetramer and an H2A-H2B dimer, was excised from the histone octamer to form a complex with Mcm2N. The histone hexamer, but not H3-H4 tetramer was released from Mcm2N in the presence of Nap1, a histone chaperone. FACT, another histone chaperone, stabilized Mcm2N-histone hexamer complex to protect from Nap1-dependent dissociation. This study indicates cooperative histone transfer via Mcm2N and histone chaperones. [ABSTRACT FROM AUTHOR]

In yeast, control of sulfur amino acid metabolism relies upon Met4 , a transcription factor that activates the expression of a network of enzymes responsible for the biosynthesis of cysteine and methionine. In times of sulfur abundance, the activity of Met4 is repressed via ubiquitination by the SCF Met30 E3 ubiquitin ligase, but the mechanism by which the F-box protein Met30 senses sulfur status to tune its E3 ligase activity remains unresolved. Herein, we show that Met30 responds to flux through the trans-sulfuration pathway to regulate the MET gene transcriptional program. In particular, Met30 is responsive to the biological gas hydrogen sulfide, which is sufficient to induce ubiquitination of Met4 in vivo. Additionally, we identify important cysteine residues in Met30 's WD-40 repeat region that sense the availability of sulfur in the cell. Our findings reveal how SCF Met30 dynamically senses the flow of sulfur metabolites through the trans-sulfuration pathway to regulate the synthesis of these special amino acids. [ABSTRACT FROM AUTHOR]

Multiple pathways are known to suppress the formation of gross chromosomal rearrangements (GCRs), which can cause human diseases including cancer. In contrast, much less is known about pathways that promote their formation. The spindle assembly checkpoint (SAC), which ensures the proper separation of chromosomes during mitosis, has been reported to promote GCR, possibly by delaying mitosis to allow GCR-inducing DNA repair to occur. Here, we show that this conclusion is the result of an experimental artifact arising from the synthetic lethality caused by the disruption of the SAC and loss of the CIN8 gene, which is often lost in the genetic assay used to select for GCRs. After correcting for this artifact, we find no role of the SAC in promoting GCR. [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]

Chemical control of Drosophila suzukii (Diptera: Drosophilidae) based on the use of insecticides is particularly challenging as the insect attacks ripening fruits shortly before harvest. An alternative strategy may rely on the use of yeasts as phagostimulants and baits, applied on canopy as attract-and-kill formulations. The aim of this research was to identify the most attractive among six yeast species for D. suzukii: Saccharomyces cerevisiae, Hanseniaspora uvarum, Clavispora santaluciae, Saccharomycopsis vini, Issatchenkia terricola, and Metschnikowia pulcherrima. The volatile profile of C. santaluciae was described for the first time. Behavioural experiments identified H. uvarum and S. vini as the most attractive yeasts. The characterization of yeast headspace volatiles using direct headspace (DHS) and solid-phase microextraction (SPME) revealed several strain-specific compounds. With DHS injection, 19 volatiles were characterised, while SPME revealed 71 compounds constituting the yeast headspace. Both analyses revealed terpenoids including β-ocimene, citronellol, (Z)-geraniol (nerol), and geranial as distinct constituents of S. vini. H. uvarum and S. vini were further investigated using closed-loop stripping analysis (CSLA) and electroantennography. Out of 14 compounds quantified by CSLA, ethyl acetate, isoamyl acetate, β-myrcene, benzaldehyde and linalool were detected by D. suzukii antennae and might generate the strong attractiveness of S. vini and H. uvarum. Our results highlight a strong attraction of D. suzukii to various yeasts associated with both the flies and their habitat and demonstrate how different sampling methods can impact the results of volatile compound characterization. It remains to be demonstrated whether the distinct attraction is based on special adaptations to certain yeasts and to what extent the metabolites causing attraction are interchangeable. [ABSTRACT FROM AUTHOR]

Techniques to study splicing kinetics include metabolic labeling time courses, 3′ splice site-RNA polymerase II distance-based measurements, and microscopy-based methods. The global median splicing time is of the order of minutes in many organisms, including yeast, Drosophila , and humans. Many instances of splicing events occurring on the order of seconds have also been observed. Single intron excision kinetics are highly variable. Many molecular features are associated with splicing kinetics, including intron length, the distance of an intron from its respective gene boundaries, and whether a splicing event is alternative or constitutive. Splicing is a highly regulated process critical for proper pre-mRNA maturation and the maintenance of a healthy cellular environment. Splicing events are impacted by ongoing transcription, neighboring splicing events, and cis and trans regulatory factors on the respective pre-mRNA transcript. Within this complex regulatory environment, splicing kinetics have the potential to influence splicing outcomes but have historically been challenging to study in vivo. In this review, we highlight recent technological advancements that have enabled measurements of global splicing kinetics and of the variability of splicing kinetics at single introns. We demonstrate how identifying features that are correlated with splicing kinetics has increased our ability to form potential models for how splicing kinetics may be regulated in vivo. [ABSTRACT FROM AUTHOR]

D-xylose is the second most abundant monosaccharide found in lignocellulose and is of biotechnological importance for producing second-generation ethanol and other high-value chemical compounds. D-xylose conversion to ethanol is promoted by microbial fermentation, mainly by bacteria, yeasts, or filamentous fungi. Among yeasts, species belonging to the CTG(Ser1) or CTG(Ala) clade display a remarkable ability to ferment D-xylose to ethanol and other compounds; however, these yeasts are not employed on an industrial scale given their poor fermentative performance compared to that of conventional yeasts, such as Saccharomyces cerevisiae, and because of the lack of a molecular toolbox for the development of new strains tailored to fermentation stress tolerance and performance. Thus, the purpose of this review was to evaluate the major genetic engineering tools (e.g., transformation markers and techniques, vectors, regulatory sequences, and gene editing techniques) available for the most studied yeasts of the CTG(Ser1) clade, such as Scheffersomyces , Spathaspora , Candida , and Yamadazyma species, and the CTG(Ala) clade, representative Pachysolen tannophilus. Furthermore, we systematized state-of-the-art molecular developments and perspectives to design D-xylose-fermenting yeast strains. • Review of genetic tools in CTG(Ser1) and CTG(Ala) yeasts for bioethanol production. • CTG codon reassignment impairs the use of conventional genetic engineering tools. • CTG(Ser1) yeasts can use genetic tools from clinically important Candida strains for research. [ABSTRACT FROM AUTHOR]

4-Vinylguaiacol (4-VG) is one of the causative compounds for the phenolic odor characteristics of brewed liquor. In the case of Japanese sake brewing, 4-VG is formed through the decarboxylation of ferulic acid produced by rice koji enzymes from steamed rice. PAD1 (phenylacrylic acid decarborxylase gene) and FDC1 (ferulic acid decarboxylase gene) genes are essential for decarboxylation of ferulic acid in Saccharomyces cerevisiae and the single polymorphisms of both genes show a relationship with ferulic acid decarboxylation ability. While most of the Kyokai yeasts distributed by the Brewing Society of Japan have homozygous non-function fdc1 alleles, many newly isolated natural yeasts for local specialities carry the wild-type FDC1 gene. In our previous research, we found that a crossbreed strain lost a significant amount of chromosomal DNA as it underwent meiosis-like adaptation. Here, we established a breeding approach to exclude undesirable gene alleles (such as the wild-type FDC1 genes) from yeast strains of interest by backcrossing using Kyokai yeasts. Homozygous fdc1 crossbreeds were generated through the three rounds of crossing procedures, and we confirmed the reduction of 4-VG in the culture supernatant of the homozygous fdc1 hybrid strain compared to the parental strain. Importantly, this approach does not include growth selection for the mutation of interest (the fdc1 mutant in the current case). Using various yeast strains generated throughout human history, it may become possible to design and build any yeast strains according to the purpose. [ABSTRACT FROM AUTHOR]

Homing genetic elements are a form of selfish DNA that inserts into a specific target site in the genome and spreads through the population by a process of biased inheritance. Two well-known types of homing element, called inteins and homing introns, were discovered decades ago. In this review we describe WHO elements, a newly discovered type of homing element that constitutes a distinct third category but is rare, having been found only in a few yeast species so far. WHO elements are inferred to spread using the same molecular homing mechanism as inteins and introns: they encode a site-specific endonuclease that cleaves the genome at the target site, making a DNA break that is subsequently repaired by copying the element. For most WHO elements, the target site is in the glycolytic gene FBA1. WHO elements differ from inteins and homing introns in two fundamental ways: they do not interrupt their host gene (FBA1), and they occur in clusters. The clusters were formed by successive integrations of different WHO elements into the FBA1 locus, the result of an 'arms race' between the endonuclease and its target site. We also describe one family of WHO elements (WHO10) that is no longer specifically associated with the FBA1 locus and instead appears to have become transposable, inserting at random genomic sites in Torulaspora globosa with up to 26 copies per strain. The WHO family of elements is therefore at the borderline between homing genetic elements and transposable elements. [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]

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Yeast feed additives present a natural approach for mitigating ruminal greenhouse gases (GHG) in an environmentally sustainable manner. This study aimed to isolate yeast strains from ruminal fluids capable of reducing GHG from Aflatoxin (AFB1) contaminated diets. Two isolates of Pichia manchuria (FFNLYFC1 and FFNLYFC2) were isolated and identified from the ruminal contents of dairy Zaraibi goats. An in vitro gas production assay was conducted to evaluate the impact of the yeast supplementations on a basal diet contaminated with AFB1 or not. The treatments were control (-AFB1; basal diet without supplements), control with AFB1 contamination (+ AFB1; basal diet containing 20 ppb AFB1), and yeast-supplemented diets (basal diet supplemented with Saccharomyces cerevisiae, and three treatments of P. manchuria [FFNLYFC1, FFNLYFC2, and their mixture at 1:1 ratio (Mix)]. High biological components were detected in abundance of both FFNLYFC1, FFNLYFC2 filtrates (e.g., diisooctyl phthalate). The Mix and FFNLYFC2 of P. manchuria reduced (P < 0.05) methane by 23.5 and 20.8%, respectively, while only Mix inhibited carbon dioxide by 44% compared to the + AFB1 diet. All yeast diets improved (P < 0.05) ammonia concentration, total protozoal and Entodinium spp. counts compared to + AFB1 diet. The Mix exhibited higher (P < 0.05) values of ruminal degraded cellulose, total short-chain fatty acids, acetate and propionate compared to the individual isolates diets. The results suggest synergistic interactions among P. manshurica isolates, leading to enhanced ruminal fermentation and reduced GHG emissions while alleviating the adverse effects of AFB1. Therefore, we recommended the Mix of P. Manchuria as a novel feed additive to ruminant diets. [ABSTRACT FROM AUTHOR]