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Melatonin is commonly found in various fruits, juices, and some fermented beverages. Its concentration in wine is influenced by soil properties, climatic factors, and yeast activity. Even if it is found in fermented beverages in relatively low proportions, melatonin still holds significant nutritional value, giving anti-aging properties, anti-inflammatory actions, and antidepressant effects. In this context, this article focuses on evaluating the impact of different Saccharomyces and non-Saccharomyces yeast species on the formation of melatonin and its contribution to wines' total antioxidant capacity. Considering that the antioxidant activity of wine is usually related to the content of phenolic compounds, ten such compounds were analyzed. The evaluation of bioactive compounds was performed using high-performance liquid chromatography (HPLC) coupled with mass spectrometry. The total antioxidant capacity of wine samples was evaluated by the ABTS+ method. The administration of bâtonnage products increased the efficiency of non-Saccharomyces yeasts. The mixtures of Saccharomyces and non-Saccharomyces yeasts generated higher values for melatonin. The results confirm a significant impact from the grape variety and the specific yeast strains on the melatonin concentration. Also, a strong dependence between antioxidant activity and melatonin levels was observed. Given the limited existing studies on the presence of melatonin in wines, new perspectives are needed for future exploration and understanding. [ABSTRACT FROM AUTHOR]

The unresolved challenges in the development of highly efficient, stable and controlled synthetic microbial consortia, as well as the use of natural consortia, are very attractive for science and technology. However, the consortia management should be done with the knowledge of how not only to accelerate but also stop the action of such "little pots". Moreover, there are a lot of microbial consortia, the activity of which should be suppressively controlled. The processes, catalyzed by various microorganisms being in complex consortia which should be slowed down or completely cancelled, are typical for the environment (biocorrosion, landfill gas accumulation, biodegradation of building materials, water sources deterioration etc.), industry (food and biotechnological production), medical practice (vaginitis, cystitis, intestinal dysbiosis, etc.). The search for ways to suppress the functioning of heterogeneous consortia in each of these areas is relevant. The purpose of this review is to summarize the general trends in these studies regarding the targets and new means of influence used. The analysis of the features of the applied approaches to solving the main problem confirms the possibility of obtaining a combined effect, as well as selective influence on individual components of the consortia. Of particular interest is the role of viruses in suppressing the functioning of microbial consortia of different compositions. [ABSTRACT FROM AUTHOR]

Fungal keratitis is a rare yet severe infection of the cornea. Fungal species distribution depends on the climate and socioeconomic status and can show regional variation. This retrospective single-center study was conducted at a tertiary eye care center and the collaborating Institute of Medical Microbiology in Switzerland. On investigating all fungal-positive corneal scrapings and contact lens assessments of patients with keratitis from January 2012 to December 2023, 206 patients were identified, of which 113 (54.9%) were female. The median age was 38 (IQR 29.8, [18–93]), and 154 (74.8%) applied contact lenses. The most commonly found pathogen was Candida spp., followed by Fusarium spp. Molds were 1.8 times more common than yeasts. Linear regression showed no significant increase or decrease in the infection rate over time (p = 0.5). In addition, 10 patients (4.9%) were found to have coinfections with Acanthamoeba, 11 (5.3%) with HSV-1, none with HSV-2, and 4 (1.9%) with VZV. This study provides a long-term overview of fungal-positive corneal scrapings and contact lens specimens of patients with fungal keratitis. Based on our results, coinfections with Acanthamoeba, HSV, and VZV are frequent, especially in patients wearing contact lenses. Thus, wearing contact lenses may facilitate coinfection in fungal keratitis. [ABSTRACT FROM AUTHOR]

Reactive oxygen species (ROS) can trigger cell death in Saccharomyces cerevisiae and other lower eukaryotic organisms. Protein structure and function may be altered by ROS produced by cellular metabolism or by exposure to environmental oxidants. This happens regardless of whether peroxidases, superoxide dismutases, or catalases are active. Depending on the redox state of cysteine residues, oxidative alteration of sulfhydryl groups in proteins may inhibit protein activity or begin alternative pathways that affect cell function. Redox control is made possible by conserved, interdependent thioredoxin and glutaredoxin systems, which may play a comparable function in metal homeostasis in eukaryotic organisms. In response to oxidative stress, gene expression in S. cerevisiae is regulated by several transcription factors, including Yap1, and Gpx3 peroxidase, and one function of Yap1 is to regulate gene expression. Notwithstanding this information, many issues about the link between ROS production and apoptosis remain unsolved. ROS may disrupt cells or activate certain molecular and cellular pathways during cell death, promoting apoptosis. This review aims to elucidate ROS’s essence, their harm to cells, how S. cerevisiae reacts to ROS, and how ROS might affect cell integrity and cause cell death.

Background: It is hypothesized that mechanical debridement (MD) with adjunct antimicrobial photodynamic therapy (aPDT) is more efficient in reducing peri-implant subgingival yeasts colonization (SYC) than MD alone. The aim of the present systematic review and meta-analysis was to evaluate randomized controlled trials (RCTs) that assessed the efficacy of MD with and without adjunct aPDT towards the reduction in peri-implant SYC. Methods: The focused question was “Is MD with adjunct aPDT more effective then MD alone in reducing peri-implant SYC?” Indexed databases were searched without time and language restrictions until February 2024. The Population/Patients, Intervention, Control, Outcome (PICO) strategy was adopted. The literature search was performed using the preferred reporting items for systematic reviews and meta-analysis guidelines. The risk of bias (RoB) was assessed using the Cochrane RoB tool. Results: Three randomized controlled trials with a follow-up duration of 90 days were included and processed for data extraction. In one study, all participants were male and in the remaining two studies, males and females were included. One study showed that peri-implant MD with adjunct aPDT is more effective in reducing SYC than MD alone. In another study, there was no significant difference in SYC following MD with or without adjunct aPDT. In one study, the role of peri-implant MD with adjunct aPDT remained unclear due to missing data. The overall RoB was high and low in one and two studies, respectively. Conclusion: The role of MD with or without adjunct aPDT in reducing peri-implant SYC remains debatable.

Floral nectar is frequently colonised by microbes. However, nectar microbial communities are typically species-poor and dominated by few cosmopolitan genera. One hypothesis is that nectar constituents may act as environmental filters. We tested how five non-sugar nectar compounds as well as elevated sugar impacted the growth of 12 fungal and bacterial species isolated from nectar, pollinators, and the environment. We hypothesised that nectar isolated microbes would have the least growth suppression. Additionally, to test if nectar compounds could affect the outcome of competition between microbes, we grew a subset of microbes in co-culture across a subset of treatments. We found that some compounds such as H2 O2 suppressed microbial growth across many but not all microbes tested. Other compounds were more specialised in the microbes they impacted. As hypothesised, the nectar specialist yeast Metschnikowia reukaufii was unaffected by most nectar compounds assayed. However, many non-nectar specialist microbes remained unaffected by nectar compounds thought to reduce microbial growth. Our results show that nectar chemistry can influence microbial communities but that microbe-specific responses to nectar compounds are common. Nectar chemistry also affected the outcome of species interactions among microbial taxa, suggesting that non-sugar compounds can affect microbial community assembly in flowers.

Comparative metatranscriptomics of the bacterial and yeast communities of two milk kefir beverages (MKAA1 and MKAA2) was carried out. They were obtained by fermentation with two different frozen stocks of the kefir grain CIDCA AGK1, differing in rheological features and production of organic acids. We hypothesised that the differences in their physicochemical and rheological properties might be due to the microbial activity in each product. The dominance of lactic acid bacteria, yeast, and a marginal amount of acetic acid bacteria characterised the microbiome. The bacterial families Lactobacillaceae and Streptococcaceae accounted for almost all of the bacterial gene transcripts, with Lactobacillus helveticus, L. kefiranofaciens, L. gallinarum, and Lactococcus lactis being most frequent in the microbiome of the MKAA1 beverage and L. kefiranofaciens, Lc. Lactis, and Leuconostoc mesenteroides being the most prevalent in MKAA2. Dipodascaceae and Saccharomycetaceae were the leading yeast families, represented by Yarrowia lipolytica, Saccharomyces unisporus, and Kluyveromyces marxianus. MKAA1 and MKAA2 shared >75% KEGG Ortologs (KOs) in their bacteria and yeast libraries. The considerable decreases in total expressed genes (KEGG Ortologs) assigned to Lactobacillus helveticus and L. gallinarum might be related to the variations in the rheological features of the beverages, probably by compromising the interrelations with L. kefiranofaciens, which might explain the variations in the rheological features of the beverages.

The ability of Candida albicans to switch its morphology from yeast to filaments, known as polymorphism, may bias the methods used in microbial quantification. Here, we compared the quantification methods [cell/mL, colony forming units (CFU)/mL, and the number of nuclei estimated by viability polymerase chain reaction (vPCR)] of three strains of C. albicans (one reference strain and two clinical isolates) grown as yeast, filaments, and biofilms. Metabolic activity (XTT assay) was also used for biofilms. Comparisons between the methods were evaluated by agreement analyses [Intraclass and Concordance Correlation Coefficients (ICC and CCC, respectively) and Bland-Altman Plot] and Pearson Correlation (α = 0.05). Principal Component Analysis (PCA) was employed to visualize the similarities and differences between the methods. Results demonstrated a lack of agreement between all methods irrespective of fungal morphology/growth, even when a strong correlation was observed. Bland-Altman plot also demonstrated proportional bias between all methods for all morphologies/growth, except between CFU/mL X vPCR for yeasts and biofilms. For all morphologies, the correlation between the methods were strong, but without linear relationship between them, except for yeast where vPCR showed weak correlation with cells/mL and CFU/mL. XTT moderately correlated with CFU/mL and vPCR and weakly correlated with cells/mL. For all morphologies/growth, PCA showed that CFU/mL was similar to cells/mL and vPCR was distinct from them, but for biofilms vPCR became more similar to CFU/mL and cells/mL while XTT was the most distinct method. As conclusions, our investigation demonstrated that CFU/mL underestimated cells/mL, while vPCR overestimated both cells/mL and CFU/mL, and that the methods had poor agreement and lack of linear relationship, irrespective of C. albicans morphology/growth.1

Abstract Background The use of industrial Cannabis sativa L. for recreational, cosmeceutical, nutraceutical, and medicinal purposes has gained momentum due to its rich content of valuable phytochemicals, such as cannabidiol (CBD) and cannabigerol (CBG). However, there are concerns regarding the risk of microbial contamination in plants grown outside controlled environments. Microbes associated with hemp can be either epiphytes or endophytes and may pose a risk of infectious illness for humans. Methods Seven Italian hemp genotypes, including Bernabeo, Carmagnola, Carmaleonte, Codimono, CS, Eletta Campana, and Fibranova, were cultivated in two distinct geographic locations, Catania and Rovigo, for three consecutive years from 2019 to 2021. Total aerobic microbes (TAMC), total combined yeasts/moulds (TYMC), the presence of bile-tolerant Gram-negative bacteria, and the absence of Escherichia coli and Salmonella spp. were evaluated and compared. The main phytocannabinoid content was measured and correlated with microbial contamination. Results Most samples analyzed in this study did not meet the European Pharmacopoeia microbiological limits. The detection of potential pathogens, such as E. coli and Salmonella spp., in the samples indicates that the use of inflorescences may represent a possible source of infection. Microbial contamination varied among harvesting seasons and production sites, with agroclimatic conditions influencing microbial load and composition. The presence of potentially pathogenic bacteria was less associated with seasonal climate variability and more likely affected by sporadic contamination from external sources. CBD concentration exhibited a negative correlation with bile-tolerant Gram-negative bacteria and total yeasts/moulds levels. Samples with lower CBD content were more contaminated than those with higher CBD levels, suggesting a potential protective effect of this phytochemical on the plant. Conclusions The threshing residues (inflorescences, floral bracts, and leaves) of industrial hemp varieties represent a valuable product and a source of beneficial phytochemicals that warrants further exploration. While post-harvest sterilization methods may reduce microbiological risks, they may also degrade heat- and light-sensitive bioactive phytochemicals. The most promising strategy involves implementing best agronomic practices to maintain healthy and uncontaminated cultures. Rigorous monitoring and quality certification protocols are essential to mitigate the microbiological risk associated with the consumption of hemp-derived products.

Sourdough are unique microbiological systems with a symbiotic interaction between lactic acid bacteria and yeasts. Yeasts, together with lactic acid bacteria, play a significant role in fermenting starters and are crucial for shaping the technological and functional properties of the product. Aim. To analyze scientific data regarding the importance of yeasts in shaping the properties of sourdough and final products. Methods. Searching and analyzing the relevant scientific literature, systematizing, and summarizing the results of available publications. Results. It was highlighted the significant role of yeasts in formation the properties of sourdough and final bakery products, particularly for dough leavening, the development of flavor and aromatic characteristics, enrichment of bread with biologically active compounds, enhancement of bioavailability and shelf-life extension. Conclusion. It was emphasized the importance of this knowledge for improving bakery production technologies using starter compositions for sourdough fermentation and the rational selection of yeast strains to regulate the organoleptic and functional-technological properties of the finished products.

Background/Aims: Recent studies indicate that probiotics, which have attracted attention as a treatment for irritable bowel syndrome, affect intestinal homeostasis. In this study, we investigated whether Zygosaccharomyces sapae (strain I-6), a probiotic yeast isolated from miso (a traditional Japanese fermented food), could improve irritable bowel syndrome symptoms. Methods: Male Wistar rats were exposed to water avoidance stress (WAS). The number of defecations during WAS and the visceral hypersensitivity before and after WAS were evaluated using colorectal distension. Tight junction changes were assessed by Western blotting. Some rats were fed with strain I-6 or β-glucan from strain I-6. Changes in the intestinal microbiota were analyzed. The effect of fecal microbiota transplantation after WAS was evaluated similarly. Caco-2 cells were stimulated with interleukin-1β and tight junction changes were investigated after coculture with strain I-6. Results: The increased number of stool pellets and visceral hypersensitivity induced by WAS were suppressed by administering strain I-6. The decrease in tight junction protein occludin by WAS was reversed by the administration of strain I-6. β-Glucan from strain I-6 also suppressed those changes induced by WAS. In the rat intestinal microbiota, treatment with strain I-6 altered the β-diversity and induced changes in bacterial occupancy. Upon fecal microbiota transplantation, some symptoms caused by WAS were ameliorated. Conclusions: These results suggest that traditional fermented foods such as miso in Japan are valuable sources of probiotic yeast candidates, which may be useful for preventing and treating stress-induced visceral hypersensitivity.

Background: The use of industrial Cannabis sativa L. for recreational, cosmeceutical, nutraceutical, and medicinal purposes has gained momentum due to its rich content of valuable phytochemicals, such as cannabidiol (CBD) and cannabigerol (CBG). However, there are concerns regarding the risk of microbial contamination in plants grown outside controlled environments. Microbes associated with hemp can be either epiphytes or endophytes and may pose a risk of infectious illness for humans. Methods: Seven Italian hemp genotypes, including Bernabeo, Carmagnola, Carmaleonte, Codimono, CS, Eletta Campana, and Fibranova, were cultivated in two distinct geographic locations, Catania and Rovigo, for three consecutive years from 2019 to 2021. Total aerobic microbes (TAMC), total combined yeasts/moulds (TYMC), the presence of bile-tolerant Gram-negative bacteria, and the absence of Escherichia coli and Salmonella spp. were evaluated and compared. The main phytocannabinoid content was measured and correlated with microbial contamination. Results: Most samples analyzed in this study did not meet the European Pharmacopoeia microbiological limits. The detection of potential pathogens, such as E. coli and Salmonella spp., in the samples indicates that the use of inflorescences may represent a possible source of infection. Microbial contamination varied among harvesting seasons and production sites, with agroclimatic conditions influencing microbial load and composition. The presence of potentially pathogenic bacteria was less associated with seasonal climate variability and more likely affected by sporadic contamination from external sources. CBD concentration exhibited a negative correlation with bile-tolerant Gram-negative bacteria and total yeasts/moulds levels. Samples with lower CBD content were more contaminated than those with higher CBD levels, suggesting a potential protective effect of this phytochemical on the plant. Conclusions: The threshing residues (inflorescences, floral bracts, and leaves) of industrial hemp varieties represent a valuable product and a source of beneficial phytochemicals that warrants further exploration. While post-harvest sterilization methods may reduce microbiological risks, they may also degrade heat- and light-sensitive bioactive phytochemicals. The most promising strategy involves implementing best agronomic practices to maintain healthy and uncontaminated cultures. Rigorous monitoring and quality certification protocols are essential to mitigate the microbiological risk associated with the consumption of hemp-derived products. [ABSTRACT FROM AUTHOR]

Fungi, including filamentous fungi and yeasts, are major contributors to global food losses and waste due to their ability to colonize a very large diversity of food raw materials and processed foods throughout the food chain. In addition, numerous fungal species are mycotoxin producers and can also be responsible for opportunistic infections. In recent years, MALDI-TOF MS has emerged as a valuable, rapid and reliable asset for fungal identification in order to ensure food safety and quality. In this context, this study aimed at expanding the VITEK® MS database with food-relevant fungal species and evaluate its performance, with a specific emphasis on species differentiation within species complexes. To this end, a total of 380 yeast and mold strains belonging to 51 genera and 133 species were added into the spectral database including species from five species complexes corresponding to Colletotrichum acutatum, Colletotrichum gloeosporioides, Fusarium dimerum, Mucor circinelloides complexes and Aspergillus series nigri. Database performances were evaluated by cross-validation and external validation using 78 fungal isolates with 96.55% and 90.48% correct identification, respectively. This study also showed the capacity of MALDI-TOF MS to differentiate closely related species within species complexes and further demonstrated the potential of this technique for the routine identification of fungi in an industrial context. [ABSTRACT FROM AUTHOR]

In this study, yeasts from the gut of O. barnabita larvae were isolated and molecularly identified. It is worth noting that this research provides the first analysis of the gut yeast community in O. barnabita larvae in Lithuania, which is a significant contribution to the field. Two hermit-like L3-praepupa instars were collected from a decaying oak log in Lithuania. The isolation, morphology, biochemistry, and physiology of the yeast isolates were characterized using standards commonly employed in yeast taxonomy studies. The isolates were identified by sequencing the large subunit (26S) rDNA (D1/D2 domain of the LSU). All gut compartments were colonized by the yeast. A total of 45 yeast strains were obtained from the gut of both O. barnabita larvae, with 23 strains originating from Larva 1, 16 strains from Larva 2, and 6 strains from the galleries. According to our identification results of the 45 yeast strains, most of the species were related to Ascomycota, with most of them belonging to the Saccharomycetales order. Yeasts of the genera Candida, Debaryomyces, Meyerozyma, Priceomyces, Schwanniomyces, Spencermartinsiella, Trichomonascus, and Blastobotrys were present in gut of O. barnabita larvae. Species of the Trichosporonales order represented the Basidiomycota phylum. [ABSTRACT FROM AUTHOR]

This study explored the impact of starter-assisted fermentation on apple blossoms to enhance their potential as a source of antioxidant and antifungal molecules. Fructobacillus fructosus PL22 and Wickerhamomyces anomalus GY1 were chosen as starters owing to their origin and promising ability to modify plant secondary metabolites. An initial assessment through microbiological and physicochemical analyses showed superior outcomes for starter-assisted fermentation compared to the spontaneous process. Enzymatic hydrolysis of proteins, primarily controlled by starters, orchestrated the generation of new low-molecular-weight peptides. W. anomalus GY1 also induced modifications in the phenolic profile, generating a diverse array of bioactive metabolites. These metabolic changes, particularly the release of potentially bioactive peptides, were associated with significant antioxidant activity and marked antifungal efficacy against three common mold species. Our results shed light on the potential of microbial starters to valorize agricultural wastes and convert them into a valuable resource for industry. [ABSTRACT FROM AUTHOR]

This work presents a low-cost, open-source turbidimeter, the 'Erlenmeter', designed to monitor the growth of microorganisms in batch cultures. It is easy to build, based exclusively on inexpensive off-the-shelf electronic components and 3D-printed parts. The Erlenmeter allows measuring the optical density of cultures on standard Erlenmeyer flasks without the need to open the flasks to collect aliquots, ensuring speed, minimal use of consumables, and elimination of the risk of contamination. These features make it particularly well-suited not just for routine research assays but also for experimental teaching. Here we illustrate the use of the Erlenmeter turbidimeter to record the growth of the microalga Phaeodactylum tricornutum, of the bacterium Escherichia coli, and of the yeast Saccharomyces cerevisiae, model organisms that are widely used in research and teaching. The Erlenmeter allows a detailed characterization of the growth curves of all organisms, confirming its usefulness for studying microbial populations dynamics both for research purposes and in classroom settings. [ABSTRACT FROM AUTHOR]

China has a 9000-year-long history of cereal-based alcohol production, with the use of molds (filamentous fungi) likely being one of the earliest fermentation techniques. This method later developed into the uniquely East Asian qu (koji) starter compound, containing grains, molds, yeasts, and bacteria. Recent studies have revealed that this method was already widely applied during the Neolithic period. However, much less is known about its development during the early dynastic times, and our knowledge of this innovation has mainly relied on textual materials. Here, we present direct evidence, based on microbotanical, microbial, and chemical analyses, for the fermentation method of a 2300-year-old liquid preserved in a sealed bronze bottle unearthed in a Qin tomb at Yancun, Shaanxi. The results of this research suggest that this liquid is likely a fermented beverage made from wheat/barley, rice, Job's tears, broomcorn millet, and pulses. The fermentation starter may have been a cereal-based qu, consisting of a wide range of microorganisms, including molds (Aspergillus and Monascus), yeasts, and bacteria. Our findings suggest that the tradition of selecting suitable grains and microbial communities for brewing alcohol, possibly with a maiqu starter (primarily wheat/barley-based qu), may have been well established more than two thousand years ago. [ABSTRACT FROM AUTHOR]

Table olives are widely produced and consumed in the Mediterranean area. The production of table olives is mainly based on spontaneous fermentations, which may have several drawbacks (e.g., the development of undesirable microorganisms; organoleptic defects) compared to fermentative processes driven by starter cultures (typically lactic acid bacteria, yeasts, or their combinations). Studies on the effect of starter cultures have been mainly focused on some technological traits (e.g., acidifying capability, the degradation of phenolic compounds, metabolite production) and, to a lesser extent, on the dynamics of olive microbiota during fermentation. Recently, the application of Amplicon Targeted—High-Throughput Sequencing (AT–HTS) has enabled improvement of the knowledge on the composition and evolution of microbial communities during fermentations, including the role of starter cultures. The AT–HTS approaches used so far, however, have several constraints (e.g., poor investigation of mycobiota and metabolically active microorganisms) that do not allow a full understanding of the complex microbial interactions occurring in fermented olives. The aim of this review is to provide insights into the role of starter cultures in fermented olives and highlight the need to apply, as for other fermented foods, integrated "omics" approaches to predict and exploit their metabolic potential to improve the final properties of products. [ABSTRACT FROM AUTHOR]

Preserving microbial ecosystems obtained from traditional cheese-making processes is crucial to safeguarding the biodiversity of microbial cheese communities and thus ensuring that the high flavor quality of traditional cheeses is maintained. Few protocols have been proposed for the long-term storage of microbial consortia. This work aimed to develop preservation methods to stabilize the entire microbial community in smear-ripened cheese without multiplication or isolation. A simplified microbial community, capable of reproducing the metabolic pattern of cheese maturation, was used in three independent cheese productions. Cheese samples were taken before and after the ripening step, mixed with maltodextrin or saline solution, and subjected to different stabilization conditions including freezing and freeze-drying, followed by 1 month of storage. Microbial survival was quantified using the colony-forming unit assay. Differential scanning calorimetry was used to relate the physical events occurring within the samples to the microbial storage stability. Freezing at −80 °C resulted in the lowest loss of culturability (<0.8 log unit), followed by freezing at −20 °C and freeze-drying. The ripening bacteria appeared as the most sensitive microorganisms within the community. Moreover, a successful cheese production using the best-stabilized community showed the possibility of preserving and re-using an entire microbial community of interest. [ABSTRACT FROM AUTHOR]

In the current study, we compared the production of extracellular lignocellulose degrading enzymes and bioethanol from the spent mushroom substrate (SMS) of Calocybe indica and Volvariella volvacea. From SMS at different stages of the mushroom development cycle, ligninolytic and hydrolytic enzymes were analysed. The activities of lignin-degrading enzymes, including lignin peroxidase (LiP), laccase, and manganese peroxidase (MnP) were maximal in the spawn run and primordial stages, while hydrolytic enzymes including xylanase, cellobiohydrolase (CBH), and carboxymethyl cellulase (CMCase) showed higher activity during fruiting bodies development and at the end of the mushroom growth cycle. SMS of V. volvacea showed relatively lower ligninase activity than the SMS of C. indica, but had the maximum activity of hydrolytic enzymes. The enzyme was precipitated with acetone and further purified with the DEAE cellulose column. The maximum yield of reducing sugars was obtained after hydrolysis of NaOH (0.5 M) pretreated SMS with a cocktail of partially purified enzymes (50% v/v). After enzymatic hydrolysis, the total reducing sugars were 18.68 ± 0.34 g/l (SMS of C. indica) and 20.02 ± 0.87 g/l (SMS of V. volvacea). We observed the highest fermentation efficiency and ethanol productivity (54.25%, 0.12 g/l h) obtained from SMS hydrolysate of V. volvacea after 48 h at 30 ± 2 °C, using co-culture of Saccharomyces cerevisiae MTCC 11,815 and Pachysolen tannophilus MTCC 1077. [ABSTRACT FROM AUTHOR]

Acorrect classification of fungi, including yeasts, is of prime importance to understand fungal biodiversity and to communicate about this diversity. Fungal genera are mainly defined based on phenotypic characteristics and the results of single or multigene-based phylogenetic analyses. However, because yeasts often have less phenotypic characters, their classification experienced a strong move towards DNA-based data, from short riboso)mal sequences to multigene phylogenies and more recently to phylogenomics. Here, we explore the usefulness of various genomics-based parameters to circumscribe fungal genera more correctly taking the yeast domain as an example. Therefore, we compared the results of a phylogenomic analysis, average amino acid identity (AAI) values, the presence of conserved signature indels (CSIs), the percentage of conserved proteins (POCP) and the presence-absence patterns of orthologs (PAPO). These genome-based metrics were used to investigate their usefulness in demarcating 13 hitherto relatively well accepted genera in Saccharomycetaceae, namely Eremothecium, Grigorovia, Kazachstania, Kluyveromyces, Lachancea, Nakaseomyces, Naumovozyma, Saccharomyces, Tetrapisispora, Torulaspora, Vanderwaltozyma, Zygosaccharomyces and Zygotorulaspora. As a result, most of these genera are supported by the genomics-based metrics, but the genera Kazachstania, Nakaseomyces and Tetrapisispora were shown to be genetically highly diverse based on the above listed analyses. Considering the results obtained for the presently recognized genera, a range of 80–92 % POCP values and a range of 60–70 % AAI values might be valuable thresholds to discriminate genera in Saccharomycetaceae. Furthermore, the genus-specific genes identified in the PAPO analysis and the CSIs were found to be useful as synapomorphies to characterize and define genera in Saccharomycetaceae. Our results indicate that the combined monophyly-based phylogenomic analysis together with genomic relatedness indices and synapomorphies provide promising approaches to delineating yeast genera and likely those of filamentous fungi as well. The genera Kazachstania, Nakaseomyces and Tetrapisispora are revised and we propose eight new genera and 41 new combinations. [ABSTRACT FROM AUTHOR]

Summary: The purpose of this research was to investigate the fermentation of Conservolea variety natural black olives using two lactic acid bacteria (LAB) with multifunctional potential as starter cultures. Moreover, the effect of 50% substitution of NaCl by KCl in the brines was examined to produce a reduced‐sodium product with multifunctional potential. For this purpose, Lactiplantibacillus pentosus B363 and Lactiplantibacillus plantarum B380, previously isolated from table olive fermentations and characterised for technological and probiotic potential, were inoculated at the onset of fermentation in 6% (w/v) NaCl and 3% (w/v) NaCl/3% (w/v) KCl salt brines. The microbial populations (LAB, yeasts, and Enterobacteriaceae), pH, acidity, salt content, organic acids, and ethanol were measured in the brine for 146 days. Additionally, the recovery of each starter culture from the olive drupes at the beginning (5 days) and final (146 days) stages of fermentation was determined by plating, genotyping, and identification through RAPD‐PCR and 16S region amplicon sequencing, respectively, and subsequent strain differentiation through rep‐GTG5 fingerprint analysis. The results revealed the dominance of LAB in populations from 5.5 to 8.1 log CFU/mL. The final recovery rate of L. pentosus B363 on the olives was approximately 80% in both 6% (w/v) NaCl and reduced (3% (w/v) NaCl/3% (w/v) KCl) salt brines. Similarly, L. plantarum B380 recovery rates were 89% and 85%, respectively, for the same fermentations. Yeasts coexisted with LAB in counts ranging from 2.3 to 5.8 log CFU/mL, whereas no enterobacteria were enumerated in the brines and olives at the end of fermentation. The obtained fermentation profile and the sensory analysis of the olives revealed a typical lactic acid fermentation in both control and reduced‐sodium brines. The current results support the feasibility of the production of reduced‐sodium natural black olives with probiotic potential. The proposed fermentation process, including the selected starters, can be readily employed by the table olive industry to meet consumers' needs for low‐sodium dietary intake while enhancing the functional potential of table olives. [ABSTRACT FROM AUTHOR]

This is the first report on abundance and diversity of cultured filamentous fungi and on abundance of yeasts in the sediments of the Laptev and East Siberian seas. A total of 63 isolates of filamentous fungi belonging to 32 morphotypes were obtained from 35 sediment samples. Most morphotypes were represented by single colonies in individual samples; the most frequently occurring species were Pseudeurotiumzonatum, Pseudogymnoascuspannorum, and Cordycepsfarinosа. In both seas, the abundance of filamentous fungi (up to 12 colonies per 1 g wet sediment) was lower than that of yeasts (up to 68 colonies per 1 g wet sediment). In the Laptev Sea, yeast abundance was low at all stations, while in the East Siberian Sea higher values were found at near-estuarine stations. [ABSTRACT FROM AUTHOR]

Objectives: This study aimed to determine the most suitable concentration of sucrose and yeast extract (SYE) and its impact on the levels of total phenol, flavonoid, and anthocyanin (TPFA) for lactic acid fermentation in mangosteen fruit peel. Materials and Methods: In this study, the primary components were mangosteen fruit peel, SYE, and lactic acid bacteria starter. The experimental design was conducted using the Factorial Design method. The colorimetric method was used to determine the total phenol (Folin-Ciocalteu reagent) and total flavonoid (AlCl3 reagent). In addition, the differential pH method was used to determine the total anthocyanins using KCl and the CH3COONa reagent. Results: The addition of SYE during the fermentation of mangosteen fruit peel significantly increased the concentrations of TPFA compared with the control (p value of 0.0001). The high sucrose concentration and low yeast extract produced the highest TPFA levels in mangosteen rind fermentation. Conclusion: The use of SYE affects the levels of TPFA in lactic acid-fermented mangosteen fruit peel, with the most suitable concentrations obtained using sucrose (45 g/L) and yeast extract (2.5 g/L). [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the effectiveness of nine different biological compounds to reduce mycotoxins concentrations. The hypothesis of this study was that a static in vitro gastrointestinal tract model, as an initial screening tool, can be used to simulate the efficacy of Geotrichum fermentans, Rhodotorula rubra, Kluyveromyce marxiamus yeast cell walls and their polysaccharides, red and white clay minerals, and walnuts nutshells claiming to detoxify AFB1, ZEA, DON, and T-2 toxin mycotoxins. Mycotoxin concentrations were analyzed using high-performance liquid chromatography (HPLC) with fluorescent (FLD) and ultraviolet detectors (UV). The greatest effects on reducing mycotoxin concentrations were determined as follows: for AFB1, inserted G. fermentans cell wall polysaccharides and walnut nutshells; for ZEA, inserted R. rubra and G. fermentans cell walls and red clay minerals; for DON, R. rubra cell wall polysaccharides and red clay minerals; and for T-2 toxin, R. rubra cell walls, K. marxianus, and G. fermentans cell wall polysaccharides and walnut nutshells. The present study indicated that selected mycotoxin-detoxifying biological compounds can be used to decrease mycotoxin concentrations. [ABSTRACT FROM AUTHOR]

Background: Onychomycosis is a chronic nail infection, and dermatophytes, yeasts, and nondermatophytic molds may be the causative agents. This study aimed to determine the etiological agents of onychomycosis by using conventional and molecular methods. Methods: Between June 2020 and July 2021, 37 patients with a presumptive diagnosis of onychomycosis and mycological evidence (culture and/or EUROArray Dermatomycosis assay) were included in the study. Organisms detected in cultured nail specimens were identified by combined phenotypic characteristics and by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). An EUROarray Dermatomycosis assay was used for molecular detection of fungal pathogens. Results: The EUROArray Dermatomycosis assay was positive for a single fungal target in 23 samples, and 14 samples were positive by culture. The most common pathogen was Trichophyton rubrum in both methods. Coinfection was detected in 14 samples by using molecular methods, and Trichophyton rubrum and Fusarium solani (9 samples) were the most common pathogens detected together. Trichophyton spp., nondermatophyte molds, and Candida spp. were detected in 33 (89.2%), 16 (43.2%), and 6 (16.2%) samples, respectively, when the two methods were evaluated together. Conclusions: Our results revealed that fungal culture allows the diagnosis of onychomycosis, but it is not as sensitive as the EUROArray Dermatomycosis test, especially in patients receiving antifungal therapy. [ABSTRACT FROM AUTHOR]

Mycoses are one of the major causes of morbidity/mortality among immunocompromised individuals. Considering the importance of these infections, the World Health Organization (WHO) defined a priority list of fungi for health in 2022 that include Candida albicans as belonging to the critical priority group and Pichia kudriavzevii (Candida krusei) to the medium priority group. The existence of few available antifungal drugs, their high toxicity, the acquired fungal resistance, and the appearance of new species with a broader spectrum of resistance, points out the need for searching for new antifungals, preferably with new and multiple mechanisms of action. The cyclam salt H4[H2(4-CF3PhCH2)2Cyclam]Cl4 was previously tested against several fungi and revealed an interesting activity, with minimal inhibitory concentration (MIC) values of 8 µg/mL for C. krusei and of 128 µg/mL for C. albicans. The main objective of the present work was to deeply understand the mechanisms involved in its antifungal activity. The effects of the cyclam salt on yeast metabolic viability (resazurin reduction assay), yeast mitochondrial function (JC-1 probe), production of reactive oxygen species (DCFH-DA probe) and on intracellular ATP levels (luciferin/luciferase assay) were evaluated. H4[H2(4-CF3PhCH2)2Cyclam]Cl4 induced a significant decrease in the metabolic activity of both C. albicans and C. krusei, an increase in Reactive Oxygen Species (ROS) production, and an impaired mitochondrial function. The latter was observed by the depolarization of the mitochondrial membrane and decrease in ATP intracellular levels, mechanisms that seems to be involved in the antifungal activity of H4[H2(4-CF3PhCH2)2Cyclam]Cl4. The interference of the cyclam salt with human cells revealed a CC50 value against HEK-293 embryonic kidney cells of 1.1 μg/mL and a HC10 value against human red blood cells of 0.8 μg/mL. [ABSTRACT FROM AUTHOR]

The selection of promising microorganisms that meet the requirements of a fermentation process is the most important stage in the development of microbiological starters. With the objective of selecting potential strains to be integrated as microbiological starters in cocoa fermentations, which promote biochemical dynamics, improving their sensory quality, the resistance of six yeasts (GRAS), isolated from cocoa fermenting masses in the departments, was evaluated. from Tolima, Huila and Antioquia, two commercial yeasts ATCC 28253 and ATCC 36633 selected for their aromatic production, subjecting them to resistance tests, at different concentrations of soluble solids (10, 15 and 20 °Brix), ethanol (5, 10%), acetic acid (pH 3, 4, 5, 6, and 7) and temperature (30, 40 and 50 °C), which simulated the biochemical dynamics of cocoa fermentation, quantifying its resistance expressed in viable cells. Aromatic production was measured by sensory evaluation. The yeasts Wickerhamomyces anomalus and Pichia kudriavzevii were selected for their ability to transform substrate into products of interest during the fermentation of cocoa pulp, production of specific aromas and resistance to adverse biochemical conditions typical of cocoa fermentation. [ABSTRACT FROM AUTHOR]

Sourdough are unique microbiological systems with a symbiotic interaction between lactic acid bacteria and yeasts. Yeasts, together with lactic acid bacteria, play a significant role in fermenting starters and are crucial for shaping the technological and functional properties of the product. Aim. To analyze scientific data regarding the importance of yeasts in shaping the properties of sourdough and final products. Methods. Searching and analyzing the relevant scientific literature, systematizing, and summarizing the results of available publications. Results. It was highlighted the significant role of yeasts in formation the properties of sourdough and final bakery products, particularly for dough leavening, the development of flavor and aromatic characteristics, enrichment of bread with biologically active compounds, enhancement of bioavailability and shelf-life extension. Conclusion. It was emphasized the importance of this knowledge for improving bakery production technologies using starter compositions for sourdough fermentation and the rational selection of yeast strains to regulate the organoleptic and functional-technological properties of the finished products. [ABSTRACT FROM AUTHOR]

Innovation in the beer market focuses on research into the different ingredients that make up this popular and sought-after beverage. Some of these innovations have focused on the use of autochthonous ingredients, which bring added value to products, reduce production costs and environmental impact, and provide beers with special organoleptic characteristics. This study focuses on the use of autochthonous ingredients from the Community of Madrid and the design of four recipes that are suited to these ingredients and consumer demand. In terms of the ingredients used, the micromalting of barley grown in the CM was carried out, while hops (Cascade variety for bittering hops and wild hops Rayo verde Tajuña and Torreta Tajuña for aroma) and yeast strains (Saccharomyces cerevisiae G 520 and G 354) were selected from previous studies, which were also sourced from the CM. For the barley malt, parameters such as protein content were determined, which was at the maximum limit but did not affect the final quality of the beers. The content of α- and β-acids in the hops was also determined, being higher in the Cascade variety. Different physicochemical analyses (GC, aromatic compounds, bitterness, colour, SO2, polyphenols, and antioxidant capacity) were carried out to determine the quality of the beers obtained from the four recipes designed, as well as tastings by a panel of experts and consumers. Finally, two recipes were rated the best by a panel of experts and consumers, where the cereal, hop, and fruit flavours stood out for their aromatic profile. [ABSTRACT FROM AUTHOR]

Background: From a recreational point of view, the sandy beaches are much frequented because they represent a space for relaxation and leisure. Due to the large number of visitors, a possible contamination of the sand by fungal microorganisms could constitute a source of transmission by potentially pathogenic saprophytic fungi. The aim of this work is to determine the biodiversity of the sand of the IFAN (Fundamental Institute of Black Africa) beach in Dakar, Senegal. Methods: We conducted a cross-sectional and descriptive study during the period from August 1, 2017, to April 1, 2018 (8 months). For every month, five sand samples of about 70 g collected at different locations on the beach were cultured on Sabouraud medium using the washing technique for yeasts and non-dermatophytic filamentous fungi isolation and the Vanbreusghem trapping technique for dermatophytes isolation. Results: Out of 45 sand samples collected, all contained at least one fungal species (100% positivity). Fifty-three (53) fungal strains composed of 12 micromycetes belonging to nine (09) different genera were isolated: Aspergillus (41.51%), Cladosporium (26.42%), Penicillium (15.09%) were the most predominant. Other species recovered comprise Cryptococcus neoformans and Candida albicans with 1.89% each. Conclusion: According to our results, the sand of IFAN beach contains a great diversity of fungal species, including fungi incriminated in human pathology. Thus, it seems that the coastal sand represents an important reservoir of fungi whose role is poorly elucidated. [ABSTRACT FROM AUTHOR]

Fungi and bacteria can be found coexisting in a wide variety of environments. The combination of their physical and molecular interactions can result in a broad range of outcomes for each partner, from competition to cooperative relationships. Most of these interactions can also be found in the human gastrointestinal tract. The gut microbiota is essential for humans, helping the assimilation of food components as well as the prevention of pathogen invasions through host immune system modulation and the production of beneficial metabolites such as short-chain fatty acids (SCFAs). Several factors, including changes in diet habits due to the progressive Westernization of the lifestyle, are linked to the onset of dysbiosis statuses that impair the correct balance of the gut environment. It is therefore crucial to explore the interactions between commensal and diet-derived microorganisms and their influence on host health. Investigating these interactions through co-cultures between human- and fermented food-derived lactobacilli and yeasts led us to understand how the strains’ growth yield and their metabolic products rely on the nature and concentration of the species involved, producing either cooperative or competitive dynamics. Moreover, single cultures of yeasts and lactobacilli proved to be ideal candidates for developing immune-enhancing products, given their ability to induce trained immunity in blood-derived human monocytes in vitro. Conversely, co-cultures as well as mixtures of yeasts and lactobacilli have been shown to induce an anti-inflammatory response on the same immune cells in terms of cytokine profiles and activation surface markers, opening new possibilities in the design of probiotic and dietary therapies.