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Ergosterol is essential for fungal cell membrane integrity and growth, and numerous antifungal drugs target ergosterol. Inactivation or modification of ergosterol biosynthetic genes can lead to changes in antifungal drug susceptibility, filamentation and stress response. Here, we found that the ergosterol biosynthesis gene ERG251 is a hotspot for point mutations during adaptation to antifungal drug stress within two distinct genetic backgrounds of Candida albicans. Heterozygous point mutations led to single allele dysfunction of ERG251 and resulted in azole tolerance in both genetic backgrounds. This is the first known example of point mutations causing azole tolerance in C. albicans. Importantly, single allele dysfunction of ERG251 in combination with recurrent chromosome aneuploidies resulted in bona fide azole resistance. Homozygous deletions of ERG251 caused increased fitness in low concentrations of fluconazole and decreased fitness in rich medium, especially at low initial cell density. Homozygous deletions of ERG251 resulted in accumulation of ergosterol intermediates consistent with the fitness defect in rich medium. Dysfunction of ERG251, together with FLC exposure, resulted in decreased accumulation of the toxic sterol (14-ɑ-methylergosta-8,24(28)-dien-3β,6α-diol) and increased accumulation of non-toxic alternative sterols. The altered sterol composition of the ERG251 mutants had pleiotropic effects on transcription, filamentation, and stress responses including cell membrane, osmotic and oxidative stress. Interestingly, while dysfunction of ERG251 resulted in azole tolerance, it also led to transcriptional upregulation of ZRT2, a membrane-bound Zinc transporter, in the presence of FLC, and overexpression of ZRT2 is sufficient to increase azole tolerance in wild-type C. albicans. Finally, in a murine model of systemic infection, homozygous deletion of ERG251 resulted in decreased virulence while the heterozygous deletion mutants maintain their pathogenicity. Overall, this study demonstrates that single allele dysfunction of ERG251 is a recurrent and effective mechanism of acquired azole tolerance. We propose that altered sterol composition resulting from ERG251 dysfunction mediates azole tolerance as well as pleiotropic effects on stress response, filamentation and virulence.

The yeast vacuole membrane can phase separate into ordered and disordered domains, a phenomenon that is required for micro-lipophagy under nutrient limitation. Despite its importance as a biophysical model and physiological significance, it is not yet resolved if specific lipidome changes drive vacuole phase separation. Here we report that the metabolism of sphingolipids (SLs) and their sorting into the vacuole membrane can control this process. We first developed a vacuole isolation method to identify lipidome changes during the onset of phase separation in early stationary stage cells. We found that early stationary stage vacuoles are defined by an increased abundance of putative raft components, including 40% higher ergosterol content and a nearly 3-fold enrichment in complex SLs (CSLs). These changes were not found in the corresponding whole cell lipidomes, indicating that lipid sorting is associated with domain formation. Several facets of SL composition-headgroup stoichiometry, longer chain lengths, and increased hydroxylations-were also markers of phase-separated vacuole lipidomes. To test SL function in vacuole phase separation, we carried out a systematic genetic dissection of their biosynthetic pathway. The abundance of CSLs controlled the extent of domain formation and associated micro-lipophagy processes, while their headgroup composition altered domain morphology. These results suggest that lipid trafficking can drive membrane phase separation in vivo and identify SLs as key mediators of this process in yeast.

Ergosterol is widely used in skin care products and drug preparation. Lanosterol 14α-demethylase (Erg11p, 14DM, CYP51) is the rate-limiting enzyme for the biosynthesis of various steroid compounds in Saccharomyces cerevisiae. Herein, Erg11p was engineered to extend the in vivo catalytic half-life and increase the turnover rate. Single mutations resulting in lower folding energy were selected, and mutant P201H had an ergosterol yield of 576.9 mg·L−1. Through consensus design, single mutations resulting in higher sequence identity to homologs were tested and mutant K352L had an ergosterol yield of 677.9 mg·L−1. The key residues for substrate binding were confirmed via alanine scanning mutagenesis and mutant F384A had an ergosterol yield of 657.8 mg·L−1. Molecular dynamics (MD) simulation was conducted to investigate the contributions of pocket residues and eight residues were found to engage in weak interactions with lanosterol. Saturation mutagenesis was applied to these residues to enhance binding to lanosterol, and mutant F384E had an ergosterol yield of 733.8 mg·L−1. Meanwhile, MD simulations were conducted to assess the impact of mutant F384E on enzyme activity. The results consistently showed that single point mutation F384E had the greatest effect, outperforming the combination mutations. Batch fermentation increased the ergosterol yield of mutant F384E to 3067.5 mg·L−1, the highest reported to date. The successful engineering of Erg11p may pave the way for industrial-scale production of ergosterol and other steroids. [ABSTRACT FROM AUTHOR]

Coffee leaf rust (CLR), caused by Hemileia vastatrix, poses a significant threat to global coffee production, resulting in substantial economic losses. This study explores the effectiveness of triazole derivatives synthesized from glycerol in controlling CLR in conilon coffee (Coffea canephora). In vitro assays evaluated the inhibitory effect of triazole derivatives (4a–4q) at concentrations of 10, 25, 50, 75 and 100 ppm on H. vastatrix urediniospore germination, followed by greenhouse experiments to assess their preventive and curative potential. Preventive and curative sprayings of the four most efficient triazoles were conducted on seedlings inoculated with H. vastatrix at concentrations ranging from 0 to 400 ppm, evaluating severity, sporulation, incubation and latent periods. Triazole derivatives 4b, 4d, 4f and 4o effectively suppressed H. vastatrix urediniospore germination, achieving reductions between 9.9% and 78.8%. In greenhouse trials, these compounds demonstrated preventive efficacy by prolonging incubation and latent periods, reducing sporulation and mitigating rust severity, with triazole 4f exhibiting the highest efficiency. Furthermore, the derivatives showed effectiveness in curative treatments, particularly triazole 4f. Physiological analyses indicated no significant alterations in coffee plant metabolism, suggesting the safety of these compounds for agricultural use. Molecular docking studies elucidated their mechanism of action, suggesting their potential as antifungal agents by interacting with the HvCYP51 enzyme involved in ergosterol biosynthesis. Overall, the study underscores the promising efficacy of glycerol‐derived triazole derivatives in managing CLR, providing sustainable solutions for disease control in agriculture. [ABSTRACT FROM AUTHOR]

The present study aimed to investigate the antifungal activity of citronellal (CIT) against clinical isolates of T. rubrum and to show the possible mechanism of action involved. The antifungal potential of CIT was evaluated from the Minimum Inhibitory Concentration (MIC), Minimum Fungicide Concentration (MFC) and assays with ergosterol and sorbitol, to elucidate the possible mechanisms of action, and molecular docking. MIC and MFC values ranged from 4 to 512 µg/mL. Regarding the mechanism of action, the monoterpene demonstrated interaction with fungal ergosterol. In addition, it is possible to observe that CIT acts on crucial enzymes for the biosynthesis and maintenance of the fungal cell membrane, due to the ability of the monoterpene to bind to CYP51. The results obtained in this research demonstrate that CIT has the potential to become, in the future, a product for the treatment of dermatophytosis. Source: Adapted from biorender.com, 2023. [ABSTRACT FROM AUTHOR]

Ergosterol possesses a variety of physiological activities, however, its application is limited due to its poor water solubility and photosensitivity. In this study, by using the ultrasonic-assisted heating method, recombinant human H-ferritin (rHuHF)–ergosterol nanocomposites (FEs) were designed, and after the characterization, the light stability, serum stability, sustained release character, and cholesterol-lowering property in vitro were analyzed. The results showed that FEs maintained a spherical morphology with the same particle size as rHuHF. About 17 ergosterol molecules were successfully encapsulated in one ferritin molecule with an encapsulation rate of (27.28 ± 0.29)% and a drug loading of (1.63 ± 0.02)%. The light stability of FEs was increased compared with free ergosterol molecules. The FEs also exhibited good serum stability. The results of simulated gastrointestinal digestion indicated that the rHuHF cage was able to prolong the release of ergosterols. FEs digesta can reduce the solubility of cholesterol in micelles. Additionally, molecular docking displayed that ergosterol can competitively inhibit cholesterol binding to human Niemann-Pick C1-Like 1 (NPC1L1), which might play an important role in preventing the delivery of cholesterol to the membrane for accumulation. This work offers an approach to encapsulate and deliver ergosterol depending on the advantage of ferritin nanocage, which has the potential to be applied in food industry. [ABSTRACT FROM AUTHOR]

Candida albicans, the most common opportunistic pathogenic fungus, is also the main pathogenic organism for oral candidiasis. This condition is particularly prevalent among the elderly, children, and individuals undergoing radiotherapy or suffering from HIV. The lack of new antifungal drugs, and drug resistance coupled with the side effects of current antifungal agents have increased the challenges of clinical antifungal therapies. Polyenes, including amphotericin B and nystatin, are clinical fungicidal drugs, however, their side effects and low solubility have limited their clinical applications. Here, we identified that moxidectin, a novel approved antiparasitic agent, could synergize with both amphotericin B and nystatin to inhibit the growth and biofilm formation of Candida albicans including 60 clinical isolates. The transcriptome and RT-PCR analysis indicated that moxidectin activated the biosynthesis pathway of ergosterol, the direct target of polyenes, further being verified by the loss of the synergistic activities with polyenes against ergosterol pathway mutants, including Δ/Δerg3, Δ/Δerg11 and Δ/Δerg3 Δ/Δerg11. Moxidectin was then confirmed to elevate the ergosterol biosynthesis levels of C. albicans and enhance the binding between cells and polyenes. In a mouse oral candidiasis model, moxidectin combined with low dosages of polyenes to significantly reduce the infection area, colonization of C. albicans and the inflammatory degree of tongue mucosa. Our study originally demonstrated that moxidectin could activate the ergosterol biosynthesis then elevate the ergosterol contents to enhance the antifungal effects of polyenes against C. albicans and its infections. Moxidectin can serve as the candidate potentiator of polyenes for further clinical practice. Key points: • Moxidectin synergized with polyenes against Candida albicans. • Moxidectin activated the ergosterol biosynthesis of Candida albicans. • Moxidectin combined with polyenes to effectively combat oral candidiasis in mice. [ABSTRACT FROM AUTHOR]

Currently, the EU is focusing on less intensive agrotechnology and sustainable development. It is important to minimize the occurrence of mycotoxins (including Fusariotixins) in food, and to monitor mycotoxin concentration in the food chain. Therefore, this study evaluated Fusarium mycotoxin contamination, specifically type A and B trichothecenes and ergosterol concentration, in wheat grain from a three-year field experiment (2019–2021) conducted at IUNG-PIB in Osiny (Poland), along with its byproducts (bran, flour, bread). Four wheat cultivars were grown under different farming systems: organic (ORG), integrated (INT), and conventional (CONV). Ergosterol was analyzed using HPLC with an absorbance detector while Type A and B trichothecenes were analyzed using gas chromatography and mass spectrometry. Results showed that the farming system significantly influenced type B trichothecenes concentration in grain, with the highest concentration established in ORG-grown wheat. However, the grain concentration from the INT farming system was comparable to that from CONV. Type A trichothecenes concentrations were low and not significantly affected by the farming system. Bran exhibited the highest ergosterol and mycotoxin concentration, while flour and bread exhibited the lowest. [ABSTRACT FROM AUTHOR]

Abscisic acid (ABA), a type of sesquiterpenoid plant hormone, has high application value in agriculture, nutrition and medicine. Herein, we constructed an efficient ABA-producing yeast cell factory by combining multidimensional engineering strategies. Starting from a suitable strain, YS010 was selected from 11 varieties of S. cerevisiae strains by evaluating ergosterol content and growth ability, then the biosynthetic pathway of ABA derived from Botris cinerea was constructed, resulting in 1.93 mg L−1 ABA. Next, the metabolic flux of the mevalonic acid (MVA) pathway was increased to enhance the synthesis of the precursor farnesyl pyrophosphate (FPP). To further increase the FPP competitiveness of the ABA synthesis pathway, we attempted to enhance the catalytic performance of BcABA3 through enzyme engineering, and the ABA yield of the mutant strain YS036-ABAPA206D reached 2.64 mg L−1 in SC-ura medium. In addition, we developed a multi-copy integration strategy, TPI1-delta driven CRISPR-Cas9 (TDI-CRISPR) integration system, to realize the high copy and stable expression of bcaba1 , bcaba2 and bcaba3 , which enabled the titer of ABA to reach 17.47 mg L−1. Finally, by optimising the fermentation medium, the ABA titer reached 30.30 mg L−1, which was the highest level ever reported for de novo ABA biosynthesis in S. cerevisiae. [Display omitted] • The engineered strain produced 30.30 mg L−1 of abscisic acid (ABA). • Rational design of α-ionylideneethane synthase (BcABA3) improved its activity. • ABA production significantly increased using the developed integration system. [ABSTRACT FROM AUTHOR]

The occurrence of Ochratoxin A (OTA) in wine is commonly known, but there is only limited information about its occurrence in grape mash and wines of German origin. Climate change has led to higher temperatures in the southern regions of Germany, which may increase the growth of fungi associated with the production of OTA and increase the content of this mycotoxin in grapes. A safe and rapid UHPLC-FLD method was developed and validated to assess the contamination of grape mash and wine with OTA. A total of 71 samples of grape mash and 30 wines from various wine producers in Baden-Württemberg, Germany, were analysed for OTA content. The results showed that no samples contained OTA in concentrations above the limit of detection. Further monitoring of samples from different vintages is needed. [ABSTRACT FROM AUTHOR]

Skeletal isomerization of ergosterol peroxide, a primary oxidation product of ergosterol, was investigated under thermal and iron(II)‐mediated conditions. Thermal isomerization resulted in not only the isolation of the predicted 7‐hydroxy‐5,6‐epoxides but also the discovery of the unprecedented 7/9/5‐ring‐fused ergostane for the first time. The iron(II)‐mediated isomerization proceeded at ambient temperature, resulting in the formation of the expected 5,6‐epoxysterols and a ring‐opened bicyclic diketone. The diketone was further converted into novel ergostane under thermal conditions and into (+)‐sarocladione under acidic conditions. All transformations from ergosterol to sarocladione, including the isolation of the unstable diketone intermediate, were achieved at ambient temperature, confirming the biosynthetic pathway of sarocladione. Several mushroom ingredients with a 5,6‐epoxy group were synthesized stereoselectively from the isomerization products, leading to the confirmation or revision of the structures of natural products. The β‐amyloid aggregation inhibitory activity of synthetic sterols was evaluated for the first time to gain insights into the potential for dementia prevention. This study is valuable both for supplying rare sterols found in mushrooms for biological studies and for shedding light on the oxidative metabolic pathways of ergosterol. [ABSTRACT FROM AUTHOR]

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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.)

Background Aims Methods Results Conclusions The by‐product of insect larval production, frass, can be applied to soil as an organic fertiliser. Its three main organic N fractions are assumed to be ureic, protein and chitin. The significance of the latter is unknown, and it is not known if lignaceous sources have been overlooked.This study sought to gauge the activities of the (respectively, lignolytic and chitinolytic) enzymes peroxidase and N‐acetyl‐ß‐D‐glucosaminidase following frass application to soil. Their activities were monitored under conditions of urease inhibition, with a particular focus on the fungal domain.Mealworm or buffalo worm frass was applied, with or without inhibitors, to a sand/soil substrate at 3% (w/w). After 16 weeks, concentrations of the fungal biomarker ergosterol and enzyme activities were determined.Soil amendment with frass had no significant effect on peroxidase activity. Fungal biomass was stimulated in particular by application of mealworm frass, which was further improved by urease inhibition. Chitinase activity was positively correlated with fungal biomass, and was increased under urease inhibition when applied with mealworm frass.There were no appreciable quantities of lignaceous compounds in the frass used in this study. Importantly, the use of urease inhibitors co‐applied with frass has demonstrated that when its ureic N breakdown is prevented, chitin becomes a significant organic N source to soil fungi. The superior fungal response to mealworm frass indicates a larger chitin content than in buffalo worm frass. [ABSTRACT FROM AUTHOR]

Cercospora leaf spot, caused by the fungus Cercospora beticola, is the most destructive foliar disease of sugarbeet worldwide. Resistance to the sterol demethylation inhibitor (DMI) fungicide tetraconazole has been previously correlated with synonymous and nonsynonymous mutations in CbCyp51. Here, we extend these analyses to the DMI fungicides prothioconazole, difenoconazole, and mefentrifluconazole in addition to tetraconazole to confirm whether the synonymous and nonsynonymous mutations at amino acid positions 144 and 170 are associated with resistance to these fungicides. Nearly half of the 593 isolates of C. beticola collected in the Red River Valley of North Dakota and Minnesota in 2021 were resistant to all four DMIs. Another 20% were resistant to tetraconazole and prothioconazole but sensitive to difenoconazole and mefentrifluconazole. A total of 13% of isolates were sensitive to all DMIs tested. We found five CbCyp51 haplotypes and associated them with phenotypes to the four DMIs. The most predominant haplotype (E170_A/L144F_C) correlated with resistance to all four DMIs with up to 97.6% accuracy. The second most common haplotype (E170_A/L144) consisted of isolates associated with resistance phenotypes to tetraconazole and prothioconazole while also exhibiting sensitive phenotypes to difenoconazole and mefentrifluconazole with up to 98.4% accuracy. Quantitative PCR did not identify differences in CbCyp51 expression between haplotypes. This study offers an understanding of the importance of codon usage in fungicide resistance and provides crop management acuity for fungicide application decisionmaking. [ABSTRACT FROM AUTHOR]

Currently, due to the increasing impact of anthropogenic factors and changes in solar activity, the temperature on Earth is rising, posing a threat to biodiversity. Lichens are among the most sensitive organisms to climate change. Elevated ambient temperatures can have a significant impact on lichens, resulting in more frequent and intense drying events that can impede metabolic activity. It has been suggested that the possession of a diverse sterol composition may contribute to the tolerance of lichens to adverse temperatures and other biotic and abiotic stresses. The major sterol found in lichens is ergosterol (ERG); however, the regulation of the ERG biosynthetic pathway, specifically the step of epoxidation of squalene to 2,3-oxidosqualene catalyzed by squalene epoxidase during stress, has not been extensively studied. In this study, we used lichen Lobaria pulmonaria as a model species that is well known to be sensitive to air pollution and habitat loss. Using in silico analysis, we identified cDNAs encoding squalene epoxidase from L. pulmonaria, designating them as LpSQE1 for the mycobiont and SrSQE1 for the photobiont Symbiochloris reticulata. Our results showed that compared with a control kept at room temperature (+20 °C), mild temperatures (+4 °C and +30 °C) did not affect the physiology of L. pulmonaria, assessed by changes in membrane integrity, respiration rates, and PSII activity. An extreme negative temperature (−20 °C) noticeably inhibited respiration but did not affect membrane stability. In contrast, treating lichen with a high positive temperature (+40 °C) significantly reduced all physiological parameters. Quantitative PCR analysis revealed that exposing thalli to −20 °C, +4 °C, +30 °C, and +40 °C stimulated the expression levels of LpSQE1 and SrSQE1 and led to a significant upregulation of Hsps. These data provide new information regarding the roles of sterols and Hsps in the response of lichens to climate change. [ABSTRACT FROM AUTHOR]

The ERG6 gene encodes the sterol C24-methyltransferase converting zymosterol to fecosterol in the ergosterol biosynthetic pathway. Here, we extend the results of functional analysis of the CgERG6 gene, which was previously shown to modulate drug susceptibility in Candida glabrata mutant cells, by demonstrating that its deletion leads to increased susceptibility to cycloheximide, 4-nitroquinoline-N-oxide and weak organic acids, and such effects are associated with attenuated virulence. Together with abrogated efflux of drug substrates by CgCdr1p and CgPdr12p, the Cgerg6Δ mutation leads to reduced cell surface hydrophobicity and decreased virulence of the mutant cells of C. glabrata. The absence of CgErg6p impacts the lipid organization and function of the plasma membrane, resulting in non-specific permeability and abrogation of normal function of membrane-bound proteins accompanied by decreased virulence in Cgerg6Δ cells. Galleria mellonella larvae were used as a non-vertebrate animal host model to determine differences in the virulence potential of C. glabrata strains (parental strain and the Cgerg6Δ deletion mutant). We found that Cgerg6Δ mutant strain attenuated in virulence caused 25–30% survival of larvae compared with parental strain. [ABSTRACT FROM AUTHOR]

In the actual industrial production process, the efficient biosynthesis and secretion of Monascus pigments (MPs) tend to take place under abiotic stresses, which often result in an imbalance of cell homeostasis. The present study aimed to thoroughly describe the changes in lipid profiles in Monascus purpureus by absolute quantitative lipidomics and tandem mass tag-based quantitative proteomics. The results showed that ammonium chloride stress (15 g/L) increased MP production while inhibiting ergosterol biosynthesis, leading to an imbalance in membrane lipid homeostasis in Monascus. In response to the imbalance of lipid homeostasis, the regulation mechanism of phospholipids in Monascus was implemented, including the inhibition of lysophospholipids production, maintenance of the ratio of PC/PE, and improvement of the biosynthesis of phosphatidylglycerol, phosphatidylserine, and cardiolipin with high saturated and long carbon chain fatty acids through the CDP-DG pathway rather than the Kennedy pathway. The inhibition of lysophospholipid biosynthesis was attributed to the upregulated expression of protein and its gene related to lysophospholipase NTE1, while maintenance of the PC/PE ratio was achieved by the upregulated expression of protein and its gene related to CTP: phosphoethanolamine cytidylyltransferase and phosphatidylethanolamine N-methyltransferase in the Kennedy pathway. These findings provide insights into the regulation mechanism of MP biosynthesis from new perspectives. IMPORTANCE Monascus is important in food microbiology as it produces natural colorants known as Monascus pigments (MPs). The industrial production of MPs has been achieved by liquid fermentation, in which the nitrogen source (especially ammonium chloride) is a key nutritional parameter. Previous studies have investigated the regulatory mechanisms of substance and energy metabolism, as well as the cross-protective mechanisms in Monascus in response to ammonium chloride stress. Our research in this work demonstrated that ammonium chloride stress also caused an imbalance of membrane lipid homeostasis in Monascus due to the inhibition of ergosterol biosynthesis. We found that the regulation mechanism of phospholipids in Monascus was implemented, including inhibition of lysophospholipids production, maintenance of the ratio of PC/PE, and improvement of biosynthesis of phosphatidylglycerol, phosphatidylserine, and cardiolipin with high saturated and long carbon chain fatty acids through the CDP-DG pathway. These findings further refine the regulatory mechanisms of MP production and secretion. [ABSTRACT FROM AUTHOR]

A lot of people use emulsion gels because they are easier to use than creams and ointments and because they release drugs faster and more thoroughly. The study's goals were to develop and clarify an antifungal emulgel that can be put on the skin. In the Miconazole Emulgel method, the gelling agent, carbopol 934 is used with great accuracy. For the water phase, Tween 20 is an emulsifier. Propylene glycol is a co-surfactant. Methyl and propyl paraben are preservatives. And liquid paraffin is the oil in the oil phase mixture. Triethanolamine is used to bring the pH of the emulgel to between 6 and 6.4. Miconazole, which is like cholesterol for fungi, stops fungi from growing by decreasing ergosterol production, which makes membranes more mobile. There were no signs of phase separation in the improved F6 formulation. The improved mix had better drug content, spreadability, extrudability and viscosity. A 14-17 mm zone of blockage showed that the antifungal worked against Candida albicans and the drug released in vitro was 97.45%. All of the items had a pH level between 6 and 6.4, which means they were safe for the skin. The results show that the topical Miconazole Emulgel with Carbopol 934 is very smooth, easy to apply and calming. [ABSTRACT FROM AUTHOR]

Fungal infections have become an important public health problem. Currently, there are only three available classes of antifungals for the treatment of invasive infections. Two of them, azoles and polyenes, target the synthesis of ergosterol or bind to sterols. A promising strategy to improve current therapies is the use of natural compounds in combinational therapies with the existing antifungals. In this work, we analyzed the changes in the susceptibility of the mutant strain of Nakaseomyces glabratus (Candida glabrata) lacking the ERG6 gene (encoding the sterol C-24 methyltransferase in ergosterol biosynthesis) in the presence of catechin and antifungal azoles. The reduced content of ergosterol in the Cgerg6Δ mutant resulted in the increased tolerance of the mutant cells to both azoles and polyenes. The combination of catechin with fluconazole or miconazole led to the growth inhibition of the azole-resistant Cgerg6Δ mutant strain. In the presence of catechin and miconazole, the Cgerg6Δ mutant fails to properly activate the expression of genes encoding the transcription factors CgYap1p and CgMsn4p, as well as the gene expression of CgCTA1, which are involved in oxidative stress response and lead to the intracellular accumulation of ROS. Finally, we show that catechin administration reduces mortality in a Galleria mellonella model infected with C. glabrata. Our work thus supports the use of catechin in combination therapies for fungal infections and shows that the CgERG6 gene could be a potential new drug target. [ABSTRACT FROM AUTHOR]

Vitamin D is a hormone-like vitamin that plays a primary physiological role in regulating calcium metabolism. In addition to endogenous synthesis through sunlight exposure, dietary supplementation with vitamin D is indispensable for maintaining optimal vitamin D levels. To ensure precision and efficacy in quantifying daily vitamin D intake among the Japanese people, we established a method to measure vitamin D in food. This method optimizes instrument costs and streamlines cumbersome processes. Initially, thin-layer chromatography (TLC) was used to separate vitamin D from food samples, followed by a quantitative analysis using gas chromatography-mass spectrometry (GC-MS) with deuterated vitamin D as an internal standard. Despite the elevated temperature conditions of GC-MS, which lead to the generation of thermal decomposition compounds, the method remains accurate and effective, with an limit of quantitation (LOQ) as low as 0.8 ng for vitamin D. Subsequently, we applied this method to quantify the vitamin D content in 120 meal samples. The meals, designed by a registered dietitian (RD), were served in the dormitory and cafeteria of a Japanese company. The total vitamin D content {mean ± standard deviation (SD)} was 14.7 ± 13.7 µg/day. The measured total vitamin D content in the meal samples, showing a congruent range of 15.7 ± 12.6 µg/day, closely aligned with the corresponding estimate derived from Excel Eiyou-kun. In summary, this study established a method using GC-MS to simultaneously measure vitamin D2 and D3 in meals, which may be suitable for analyzing food samples for their vitamin D content in large quantities. [ABSTRACT FROM AUTHOR]

Abstract Lichen-forming fungi (LFF) are prolific producers of functionally and structurally diverse secondary metabolites, most of which are taxonomically exclusive and play lineage-specific roles. To date, widely distributed, evolutionarily conserved biosynthetic pathways in LFF are not known. However, this idea stems from polyketide derivatives, since most biochemical research on lichens has concentrated on polyketide synthases (PKSs). Here, we present the first systematic identification and comparison of terpene biosynthetic genes of LFF using all the available Lecanoromycete reference genomes and 22 de novo sequenced ones (111 in total, representing 60 genera and 23 families). We implemented genome mining and gene networking approaches to identify and group the biosynthetic gene clusters (BGCs) into networks of similar BGCs. Our large-scale analysis led to the identification of 724 terpene BGCs with varying degrees of pairwise similarity. Most BGCs in the dataset were unique with no similarity to a previously known fungal or bacterial BGC or among each other. Remarkably, we found two BGCs that were widely distributed in LFF. Interestingly, both conserved BGCs contain the same core gene, i.e., putatively a squalene/phytoene synthase (SQS), involved in sterol biosynthesis. This indicates that early gene duplications, followed by gene losses/gains and gene rearrangement are the major evolutionary factors shaping the composition of these widely distributed SQS BGCs across LFF. We provide an in-depth overview of these BGCs, including the transmembrane, conserved, variable and LFF-specific regions. Our study revealed that lichenized fungi do have a highly conserved BGC, providing the first evidence that a biosynthetic gene may constitute essential genes in lichens.

Decades of previous efforts to develop renal-sparing polyene antifungals were misguided by the classic membrane permeabilization model1. Recently, the clinically vital but also highly renal-toxic small-molecule natural product amphotericin B was instead found to kill fungi primarily by forming extramembraneous sponge-like aggregates that extract ergosterol from lipid bilayers2-6. Here we show that rapid and selective extraction of fungal ergosterol can yield potent and renal-sparing polyene antifungals. Cholesterol extraction was found to drive the toxicity of amphotericin B to human renal cells. Our examination of high-resolution structures of amphotericin B sponges in sterol-free and sterol-bound states guided us to a promising structural derivative that does not bind cholesterol and is thus renal sparing. This derivative was also less potent because it extracts ergosterol more slowly. Selective acceleration of ergosterol extraction with a second structural modification yielded a new polyene, AM-2-19, that is renal sparing in mice and primary human renal cells, potent against hundreds of pathogenic fungal strains, resistance evasive following serial passage in vitro and highly efficacious in animal models of invasive fungal infections. Thus, rational tuning of the dynamics of interactions between small molecules may lead to better treatments for fungal infections that still kill millions of people annually7,8 and potentially other resistance-evasive antimicrobials, including those that have recently been shown to operate through supramolecular structures that target specific lipids9.

Objectives: This study evaluated the role of Upc2 in the development of azole resistance in Candida albicans isolates from Lebanese hospitalized patients and determined a correlation between resistance and virulence. Methods: The UPC2 gene which codes for an ergosterol biosynthesis regulator was sequenced and analysed in two azole-resistant and one azole-susceptible C. albicans isolates. An amino acid substitution screening was carried out on Upc2 with a focus on its ligand binding domain (LBD) known to interact with ergosterol. Then, Upc2 protein secondary structure prediction and homology modelling were conducted, followed by total plasma membrane ergosterol and cell wall chitin quantifications. For virulence, mouse models of systemic infection were generated and an agar adhesion and invasion test was performed. Results: Azole-resistant isolates harboured novel amino acid substitutions in the LBD of Upc2 and changes in protein secondary structures were observed. In addition, these isolates exhibited a significant increase in plasma membrane ergosterol content. Resistance and virulence were inversely correlated while increased cell wall chitin concentration does not seem to be linked to resistance since even though we observed an increase in chitin concentration, it was not statistically significant. Conclusions: The azole-resistant C. albicans isolates harboured novel amino acid substitutions in the LBD of Upc2 which are speculated to induce an increase in plasma membrane ergosterol content, preventing the binding of azoles to their target, resulting in resistance.

Societal Impact Statement Efficient mitigation of climate change requires predictive models of forest ecosystems as sinks for atmospheric carbon. Mycorrhizal fungi are drivers of soil carbon storage in boreal forests, yet they are typically excluded from ecosystem models, because of a lack of information about their growth and turnover. Closing this knowledge gap could help us better predict future responses to climate change and guide policy decisions for sustainable management of forest ecosystems. This study provides new estimates of the production and turnover of mycorrhizal mycelial biomass and necromass. This information can facilitate the integration of mycorrhizal fungi into new predictive models of boreal forest soils. Summary In boreal forests, turnover of biomass and necromass of ectomycorrhizal extraradical mycelia (ERM) are important for mediating long‐term carbon storage. However, ectomycorrhizal fungi are usually not considered in ecosystem models, because data for parameterization of ERM dynamics is lacking. Here, we estimated the production and turnover of ERM biomass and necromass across a hemiboreal Pinus sylvestris chronosequence aged 12 to 100 years. Biomass and necromass were quantified in sequentially harvested in‐growth bags, and incubated in the soil for 1–24 month, and Bayesian calibration of mathematical models was applied to arrive at parametric estimates of ERM production and turnover rates of biomass and necromass. Steady states were predicted to be nearly reached after 160 and 390 growing season days, respectively, for biomass and necromass. The related turnover rates varied with 95% credible intervals of 1.7–6.5 and 0.3–2.5 times yr−1, with mode values of 2.9 and 0.9 times yr−1, corresponding to mean residence times of 62 and 205 growing season days. Our results highlight that turnover of necromass is one‐third of biomass. This together with the variability in the estimates can be used to parameterize ecosystem models, to explicitly include ERM dynamics and its impact on mycorrhizal‐derived soil carbon accumulation in boreal forests.

Background: Malassezia furfur (M. furfur) is a prevalent dermatophyte that significantly impairs patients' quality of life. This study aimed to evaluate the synergistic antifungal effects of combined extracts from Rosa rugosa Thunb. (MG) and Coptidis Rhizoma (HL) against M. furfur, both in vitro and in vivo. Methods: High-performance liquid chromatography (HPLC) was used to identify the major active compounds present in MG and HL. The antifungal activity of the combined Meilian extract (ML) was assessed using the checkerboard method and time-kill curves. Microstructural alterations in the fungi were observed using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The impact of the extracts on the fungal cell membrane was investigated through propidium iodide staining, protein concentration assays, and ergosterol quantification. Transcriptomic analysis was conducted to elucidate the molecular mechanisms underlying the effects of the extracts. Furthermore, the synergistic antifungal effects of ML were evaluated in a mouse model of seborrheic dermatitis induced by M. furfur. Results: The study demonstrated that the combined application of MG and HL significantly affected the integrity of the M. furfur cell membrane and potentially modulated its formation processes. In the M. furfur-induced seborrheic dermatitis model, ML exhibited synergistic antifungal effects and effectively alleviated skin inflammation. These findings provide an important theoretical basis for understanding the antifungal mechanisms of ML and its potential application in dermatological therapy. [ABSTRACT FROM AUTHOR]

Histidine kinases (HKs) are important sensor proteins in fungi and play an essential role in environmental adaptation. However, the mechanisms by which fungi sense and respond to fungivores attack via HKs are not fully understood. In this study, we utilized Neurospora crassa to investigate the involvement of HKs in responding to fungivores attack. We found that the 11 HKs in N. crassa not only affected the growth and development, but also led to fluctuations in antioxidant production. Ten mutants in the genes encoding HKs (except ∆phy1) showed increased production of reactive oxygen species (ROS), especially upon Sinella curviseta attack. The ROS burst triggered changes in conidia and perithecial beaks formation, as well as accumulation of β-glucan, ergothioneine, ergosterol, and carotenoids. β-glucan was increased in ∆hk9, ∆os1, ∆hcp1, ∆nik2, ∆sln1, ∆phy1 and ∆phy2 mutants compared to the wild-type strain. In parallel, ergothioneine accumulation was improved in ∆phy1 and ∆hk16 mutants and further increased upon attack, except in ∆os1 and ∆hk16 mutants. Additionally, fungivores attack stimulated ergosterol and dehydroergosterol production in ∆hk9 and ∆os1 mutants. Furthermore, deletion of these genes altered carotenoid accumulation, with wild-type strain, ∆hk9, ∆os1, ∆hcp1, ∆sln1, ∆phy2, and ∆dcc1mutants showing an increase in carotenoids upon attack. Taken together, HKs are involved in regulating the production of conidia and antioxidants. Thus, HKs may act as sensors of fungivores attack and effectively improve the adaptive capacity of fungi to environmental stimuli. [ABSTRACT FROM AUTHOR]

Phytoene is an uncommon linear carotene within the carotenoid group as it is colorless due to its short chromophore. Recent research constitutes a relatively new area which has emerged from phytoene's importance as a major dietary carotenoid promoting health and appearance. Its resources point to the potential of biotechnological production systems. Our work has been designed to study the efficacy of two colored carotenoid biosynthesis inhibitors, diphenylamine and 2-methyl imidazole, and one sterol biosynthesis inhibitor, terbinafine, to modify the metabolic flux in mated cultures of Blakeslea trispora to achieve maximum phytoene production. Bioprocess kinetics optimized by response surface methodology and monitored by high-performance liquid chromatography revealed maximum phytoene content (5.02 mg/g dry biomass) and yield (203.91 mg/L culture medium) comparable or even higher than those reported for other potent phytoene microbial producers. The in vivo antioxidant activity of phytoene-rich carotenoid extract from fungal cells was also considered and discussed. [ABSTRACT FROM AUTHOR]

Verticillium dahliae is a soil-borne fungal pathogen that can cause severe vascular wilt in many plant species. Kelch repeat proteins are essential for fungal growth, resistance, and virulence. However, the function of the Kelch repeat protein family in V. dahliae is unclear. In this study, a Kelch repeat domain-containing protein DK185_4252 (VdLs.17 VDAG_08647) included in the conserved VdPKS9 gene cluster was identified and named VdKeR1. Phylogenetic analysis demonstrated a high degree of evolutionary conservation of VdKeR1 and its homologs among fungi. The experimental results showed that the absence of VdKeR1 impaired vegetative growth, microsclerotia development, and pathogenicity of V. dahliae. Osmotic and cell wall stress analyses suggested that VdKeR1-deleted mutants were more tolerant to NaCl, sorbitol, CR, and CFW, while more sensitive to H2O2 and SDS. In addition, analyses of the relative expression level of sqe and the content of squalene and ergosterol showed that VdKeR1 mediates the synthesis of squalene and ergosterol by positively regulating the activity of squalene epoxidase. In conclusion, these results indicated that VdKeR1 was involved in the growth, stress resistance, pathogenicity, and ergosterol metabolism of V. dahliae. Investigating VdKeR1 provided theoretical and experimental foundations for subsequent control of Verticillium wilt. [ABSTRACT FROM AUTHOR]

To date, there are no real physiological mechanisms for iron excretion in eukaryote, and no physiological "actuator" that can control all the three fundamental biologic processes of absorption, storage, and excretion. Here, we observed that the accumulation of anthraquinones by Thermomyces dupontii under cold stress can achieve this process. Through mutation analysis, we found that mutant ΔAn deficiency in anthraquinones accumulated ferrous and total free iron due to adopting a rare lifestyle with no endocytosis but accumulation of membrane‐derived vesicles. Anthraquinone complement indicated that the vesicles in ΔAn could coat the extrinsic anthraquinone‐induced granules to prevent contact with the fungal interiors. Detailed chemical investigation on ΔAn led to characterization of a rare oxygen‐free ergosterene with unstable nature in air as the major membrane steroid in ΔAn, suggesting hypoxia inner in ΔAn cells, consistent with dramatically low oxygen‐consuming rates in ΔAn. A series of physiological and metabolic analyses indicated anthraquinones were involved in exporting ferrous and promoting formation of oxygen‐containing metabolites, including ergosterols for endocytosis and iron chelators for iron storage. Moreover, we found that both the anticancer agent mitoxantrone with well‐known‐cardiotoxicity side effect and the major terpenoid‐derived polycyclic aromatics from Danshen for treating cardiovascular disease showed potent ferrous transporting capabilities in human cancer cells. Our findings provide a novel insight into the underlying mechanisms of polycyclic aromatics in nature and pharmacology, and offer a new strategy for developing potential therapeutics and agents for membrane transport, iron homestasis, and anticold. [ABSTRACT FROM AUTHOR]

Ganoderma lucidum has anti-tumor effects, but its mechanism of action against lung cancer is not clear. This study aims to use molecular docking and network pharmacology to investigate how G. lucidum inhibits tumor growth in lung cancer and how this relationship relates to the degree of immune cell infiltration. By utilizing the TCMSP database, the therapeutic targets and active ingredients of G. lucidum were discovered. Based on the targets found in subsequent rounds of screening, a protein interaction (PPI) network was constructed. Additionally, enrichment analysis was conducted using GO and the KEGG. The molecular docking was conducted with the help of AutoDock Tools and PyMOL. Finally, we investigated the relationships between immune cells and the commonalities between lung cancer and. The primary targets of G. lucidum's anti-lung cancer activities, according to network pharmacology studies, are ADRB2, OPRM1, SLC6A4, and JUN. The primary components of the lung cancer fighter Ergosterol are ganoderal B, ganolucidic acid E, and beta-sitosterol. The molecular docking analysis revealed that beta-sitosterol had the highest degree of stability in its docking interaction with JUN. The immune infiltration analysis indicated a potential correlation between the biomarkers associated with G. lucidum treatment for lung cancer and the immune infiltrating cells. G. lucidum combats lung cancer by targeting multiple components and signaling pathways, facilitating cancer cell apoptosis and interacting with immune responses. This elucidates potential avenues for future research into G. lucidum's mechanisms in lung cancer therapy. [ABSTRACT FROM AUTHOR]

Fungal infections are among the most common diseases of crop plants. Various species of the Fusarium spp. are naturally prevalent and globally cause the qualitative and quantitative losses of farming commodities, mainly cereals, fruits, and vegetables. In addition, Fusarium spp. can synthesize toxic secondary metabolites—mycotoxins under high temperature and humidity conditions. Among the strategies against Fusarium spp. incidence and mycotoxins biosynthesis, the application of biological control, specifically natural plant extracts, has proved to be one of the solutions as an alternative to chemical treatments. Notably, rowanberries taken from Sorbus aucuparia are a rich source of phytochemicals, such as vitamins, carotenoids, flavonoids, and phenolic acids, as well as minerals, including iron, potassium, and magnesium, making them promising candidates for biological control strategies. The study aimed to investigate the effect of rowanberry extracts obtained by supercritical fluid extraction (SFE) under different conditions on the growth of Fusarium (F. culmorum and F. proliferatum) and mycotoxin biosynthesis. The results showed that various extracts had different effects on Fusarium growth as well as ergosterol content and mycotoxin biosynthesis. These findings suggest that rowanberry extracts obtained by the SFE method could be a natural alternative to synthetic fungicides for eradicating Fusarium pathogens in crops, particularly cereal grains. However, more research is necessary to evaluate their efficacy against other Fusarium species and in vivo applications. [ABSTRACT FROM AUTHOR]

Ganoderma, a traditional medicine in Asian countries, has been used to prevent and treat various ailments for centuries. Ganoderma neo-japonicum (synonym Ganoderma bambusicola), also known as purple Lingzhi, is a species that is currently underutilised when compared to Ganoderma lucidum (Lingzhi). However, in recent decades, this mushroom has garnered significant attention due to its ethnomedicinal uses, especially in Southeast Asia regions like Malaysia. The taxonomy and nomenclature of this mushroom have been extensively studied. Numerous publications have reported that G. neo-japonicum displays a variety of medicinal properties, including antioxidation, anticancer, anti-hyperglycaemic, genoprotective, hepatoprotective, neuritogenic, and antidiabetic effects, both in vitro and in vivo. With the surge of research findings on this mushroom, this review aims to provide a systematic bibliometric analysis of G. neo-japonicum, published between 1991 to 2021. Additionally, the taxonomic description of this mushroom is discussed in detail. Our review reveals that G. neo-japonicum contains polysaccharides (α/β-D-glucans), triterpenoids, and sterols/ergosterol. However, the existing literature suggests that these active compounds have not yet been explored to their full potential as drug candidates. Moreover, most of the studies are preclinical and have several drawbacks. In conclusion, G. neo-japonicum possesses valuable pharmacological activities that merit further exploration. [ABSTRACT FROM AUTHOR]

Copyright of Modern Food Science & Technology is the property of Editorial Office of Modern Food Science & Technology 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.)

Sterol biosynthesis has evolved early in the history of eukaryotes. In most animals, as well as in primitive fungi, the main sterol is cholesterol. During the process of evolution, fungi acquired the ability to synthesize ergosterol. The pathway of its biosynthesis is more complex than the one of cholesterol biosynthesis. However, the evolutionary choice of most fungi was ergosterol, and the reason for this choice is still debated. In the majority of the works on this issue, the choice of most fungi is associated with the transition to life on land, and, consequently, the danger of cell dehydration. In our review we oppose this point of view. Probably, compared to cholesterol, ergosterol has more pronounced antioxidant properties. Indeed, the presence of three double bonds in the structure of the ergostеrol molecule, as compared to one in cholesterol, increases the probability of interaction with reactive oxygen species. Perhaps, the transition to life on land required additional antioxidant protection. Due to the aforementioned structural differences, the molecule of cholesterol is apparently more flexible than that of ergosterol. Experimental data indicate that this feature provides greater membrane flexibility as compared to fungal membranes, as well as a greater ability to compensate for disturbances in the packing of membrane phospholipids. Presumably, for animal cells these qualities turned out to be relatively more important than antioxidant ones, which predetermined their evolutionary choice of sterol. [ABSTRACT FROM AUTHOR]

The limited arsenal of antifungal drugs have prompted the search for novel molecules with biological activity. This study aimed to characterize the antifungal mechanism of action of Eugenia uniflora extract and its synergistic activity with commercially available antifungal drugs on the following Candida species: C. albicans, C. tropicalis, C. glabrata, C. parapsilosis and C. dubliniensis. In silico analysis was performed to predict antifungal activity of the major compounds present in the extract. Minimal inhibitory concentrations (MICs) were determined in the presence of exogenous ergosterol and sorbitol. Yeast cells were grown in the presence of stressors. The loss of membrane integrity was assessed using propidium iodide staining (fluorescence emission). Synergism between the extract and antifungal compounds (in addition to time kill-curves) was determined. Molecular docking revealed possible interactions between myricitrin and acid gallic and enzymes involved in ergosterol and cell wall biosynthesis. Candida cells grown in the presence of the extract with addition of exogenous ergosterol and sorbitol showed 2 to 8-fold increased MICs. Strains treated with the extract revealed greater loss of membrane integrity when compared to their Fluconazole counterparts, but this effect was less pronounced than the membrane damage caused by Amphotericin B. The extract also made the strains more susceptible to Congo red and Calcofluor white. A synergistic action of the extract with Fluconazole and Micafungin was observed. The E. uniflora extract may be a viable option for the treatment of Candida infections. [ABSTRACT FROM AUTHOR]

Polyenes are a class of organic compounds well known for their potent antifungal properties. They are effective due to their ability to target and disrupt fungal cell membranes by binding to ergosterol and forming pores. Despite their effectiveness as antifungal drugs, polyenes have several limitations, such as high toxicity to the host cell and poor solubility in water. This has prompted ongoing research to develop safer and more efficient derivatives to overcome such limitations while enhancing their antifungal activity. In this review article, we present a thorough analysis of polyene derivatives, their structural modifications, and their influence on their therapeutic effects against various fungal strains. Key studies are discussed, illustrating how structural modifications have led to improved antifungal properties. By evaluating the latest advancements in the synthesis of polyene derivatives, we highlight that incorporating amide linkers at the carboxylic moiety of polyene molecules notably improves their antifungal properties, as evidenced by derivatives 4, 5, 6G, and 18. This review can help in the design and development of novel polyene-based compounds with potent antifungal activities. [ABSTRACT FROM AUTHOR]

In freshwater ecosystems, consumers can play large roles in nutrient cycling by modifying nutrient availability for autotrophic and heterotrophic microbes. Nutrients released by consumers directly support green food webs based on primary production and brown food webs based on decomposition. While much research has focused on impacts of consumer driven nutrient dynamics on green food webs, less attention has been given to studying the effects of these dynamics on brown food webs.Freshwater mussels (Bivalvia: Unionidae) can dominate benthic biomass in aquatic systems as they often occur in dense aggregations that create biogeochemical hotspots that can control ecosystem structure and function through nutrient release. However, despite functional similarities as filter‐feeders, mussels exhibit variation in nutrient excretion and tissue stoichiometry due in part to their phylogenetic origin. Here, we conducted a mesocosm experiment to evaluate how communities of three phylogenetically distinct species of mussels individually and collectively influence components of green and brown food webs.We predicted that the presence of mussels would elicit a positive response in both brown and green food webs by providing nutrients and energy via excretion and biodeposition to autotrophic and heterotrophic microbes. We also predicted that bottom‐up provisioning of nutrients would vary among treatments as a result of stoichiometric differences of species combinations, and that increasing species richness would lead to greater ecosystem functioning through complementarity resulting from greater trait diversity.Our results show that mussels affect the functioning of green and brown food webs through altering nutrient availability for both autotrophic and heterotrophic microbes. These effects are likely to be driven by phylogenetic constraints on tissue nutrient stoichiometry and consequential excretion stoichiometry, which can have functional effects on ecosystem processes. Our study highlights the importance of measuring multiple functional responses across a gradient of diversity in ecologically similar consumers to gain a more holistic view of aquatic food webs. [ABSTRACT FROM AUTHOR]

Copyright of Acta Edulis Fungi is the property of Acta Edulis Fungi 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.)

Azole antifungals inhibit the sterol C14-demethylase (CYP51/Erg11) of the ergosterol biosynthesis pathway. Here we show that the azole-induced synthesis of fungicidal cell wall carbohydrate patches in the pathogenic mold Aspergillus fumigatus strictly correlates with the accumulation of the CYP51 substrate eburicol. A lack of other essential ergosterol biosynthesis enzymes, such as sterol C24-methyltransferase (Erg6A), squalene synthase (Erg9) or squalene epoxidase (Erg1) does not trigger comparable cell wall alterations. Partial repression of Erg6A, which converts lanosterol into eburicol, increases azole resistance. The sterol C5-desaturase (ERG3)-dependent conversion of eburicol into 14-methylergosta-8,24(28)-dien-3β,6α-diol, the "toxic diol" responsible for the fungistatic activity against yeasts, is not required for the fungicidal effects in A. fumigatus. While ERG3-lacking yeasts are azole resistant, ERG3-lacking A. fumigatus becomes more susceptible. Mutants lacking mitochondrial complex III functionality, which are much less effectively killed, but strongly inhibited in growth by azoles, convert eburicol more efficiently into the supposedly "toxic diol". We propose that the mode of action of azoles against A. fumigatus relies on accumulation of eburicol which exerts fungicidal effects by triggering cell wall carbohydrate patch formation. Azole antifungals inhibit the ergosterol biosynthesis enzyme CYP51, but their effects on fungal viability and growth vary greatly among fungal species. Here, the authors provide evidence that the mode of action of azoles against Aspergillus fumigatus relies on accumulation of the CYP51 substrate eburicol, which exerts fungicidal effects by triggering cell-wall carbohydrate patch formation. [ABSTRACT FROM AUTHOR]

In the present study, we investigated the effect of supercritical carbon-oxide (scCO2) extraction on antioxidant capacity, enzyme inhibitory potential, and levels of ergosterol and ganoderic acid in both cultivated and wild-grown G. lucidum. Extraction yields were slightly higher for wild samples (1.29%) than for cultivated ones (1.13%). The levels of ganoderic acid and ergosterol were higher in cultivated in comparison to wild samples. In addition, the total phenolic content in cultivated samples (13.42 mg GAE g−1) was higher than in wild samples (10.38 mg GAE g−1). In general, cultivated samples exhibited stronger antioxidant potential when compared with wild ones. Regarding enzyme inhibitory properties, it was validated that the wild samples (14.01 mg OE g−1) possessed greater lipase activity in comparison to cultivated samples (5.36 mg OE g−1). Based on our findings, cultivated G. lucidum might be considered a valuable source of natural bioactive agents in the preparation of health-promoting products. [ABSTRACT FROM AUTHOR]

Tachysterol is an intermediate product in the synthesis of vitamin D2 from ergosterol and vitamin D3 from 7-dehydrocholesterol under ultraviolet irradiation. Recent studies have shown that tachysterol is also a crucial intermediate in the synthesis of the natural anti-tumor product Chaxine C. Although there have been numerous studies on the synthesis of vitamin D2 and other photoisomers from ergosterol, research on the synthesis of tachysterol is relatively limited. In addition, the yield of tachysterol is not high (57.0%), and the mechanism is unclear. In this study, a method was developed for the qualitative and quantitative analysis of tachysterol. Meanwhile, an efficient synthesis process for tachysterol was reported. The qualitative and quantitative analysis of ergosterol isomers, including tachysterol, a precursor of vitamin D2, and photosterol, was conducted using high-performance liquid chromatography, and the quantitative method for tachysterol was confirmed using quantitative nuclear magnetic resonance. There were strong linear relationships between tachysterol content and the testing parameters, with the correlation coefficients of 0.9997 and 0.9971, respectively. The synthesis process of tachysterol from ergosterol through our self-designed photoreactors was optimized, and the effects of reaction temperature, reaction time, photoprotectants, reaction substrate concentration, and the power of ultraviolet lamps were investigated. The yield of the reaction was 85.7%, which is 28.7% higher than the previously reported results. The mechanism and by-products of the reaction were further studied using ultraviolet spectrophotometry and gas chromatography mass spectrometry. This study explored the potential for the large-scale preparation of tachysterol, particularly for the total synthesis of the anti-tumor natural product Chaxine C. It also offered insights into the synthesis of structural similar compounds and the analysis of photocatalytic reaction products. [ABSTRACT FROM AUTHOR]

The present study aimed to detect the production of Ergosterol in Chlorella sorokinana and the effect of sodium chloride (NaCl), and the difference of growth phases on the production of the compound and photosynthetic pigments. The results showed that there is a positive effect on increasing the production of the Ergosterol compound. Its maximum value was 48.591 mg. L-1 at the concentration of 300 ppm. Concerning the difference in growth phases, the second growth phase was the best in obtaining the maximum value of Ergosterol, which was 44. 941 mg. L-1. Also, the results of the interaction between the concentrations of NaCl and the difference in the growth phases indicated that the highest value was 50.493 mg. L-1 at the concentration of 300 ppm at the second growth phase. In contrast, there was a negative effect of NaCl on photosynthetic pigments; the highest values of chlorophyll a and b and total chlorophyll were 0.04, 0.07, and 0.13, respectively, at the control treatment, whereas these values gradually decreased with the increase of NaCl concentration to reach the lowest values; these were 0.01, 0.04 and 0.06 mg. L-1 respectively at the concentration of 300 ppm. The results of the different dates of cell harvesting showed that the highest values for obtaining an increase in the concentration of chlorophyll a and b pigments and total chlorophyll were at phases 1; they were 0.06, 0.09, and 0.17 mg. L-1 respectively. Accordingly, we concluded that the salt stress from NaCl had a positive effect on increasing the concentration of Ergosterol, which is one of the antioxidant steroidal compounds. On the other hand, it had a negative effect on the photosynthetic pigments. [ABSTRACT FROM AUTHOR]

Sterols and the reductant nicotinamide adenine dinucleotide phosphate (NADPH), essential for eukaryotic life, arose because of, and as an adaptation to, rising levels of molecular oxygen (O2). Hence, the NADPH and O2‐intensive process of sterol biosynthesis is inextricably linked to redox status. In mammals, cholesterol biosynthesis is exquisitely regulated post‐translationally by multiple E3 ubiquitin ligases, with membrane associated Really Interesting New Gene (RING) C3HC4 finger 6 (MARCHF6) degrading at least six enzymes in the pathway. Intriguingly, all these MARCHF6‐dependent enzymes require NADPH. Moreover, MARCHF6 is activated by NADPH, although what this means for control of cholesterol synthesis is unclear. Indeed, this presents a paradox for how NADPH regulates this vital pathway, since NADPH is a cofactor in cholesterol biosynthesis and yet, low levels of NADPH should spare cholesterol biosynthesis enzymes targeted by MARCHF6 by reducing its activity. We speculate MARCHF6 helps mammalian cells adapt to oxidative stress (signified by low NADPH levels) by reducing degradation of cholesterogenic enzymes, thereby maintaining synthesis of protective cholesterol. [ABSTRACT FROM AUTHOR]

Highlights: Aspergillus epidemiology and prophylaxis. Azole antifungal agent’s action mechanisms. Azole resistance in Aspergillus fumigatus and its molecular mechanisms. Azole resistant A. fumigatus prevalence.Aspergillus fumigatus is a ubiquitous filamentous fungus commonly found in the environment. It is also an opportunistic human pathogen known to cause a range of respiratory infections, such as invasive aspergillosis, particularly in immunocompromised individuals. Azole antifungal agents are widely used for the treatment and prophylaxis of Aspergillus infections due to their efficacy and tolerability. However, the emergence of azole resistance in A. fumigatus has become a major concern in recent years due to their association with increased treatment failures and mortality rates. The development of azole resistance in A. fumigatus can occur through both acquired and intrinsic mechanisms. Acquired resistance typically arises from mutations in the target enzyme, lanosterol 14-α-demethylase (Cyp51A), reduces the affinity of azole antifungal agents for the enzyme, rendering them less effective, while intrinsic resistance refers to a natural resistance of certain A. fumigatus isolates to azole antifungals due to inherent genetic characteristics. The current review aims to provide a comprehensive overview of azole antifungal resistance in A. fumigatus, discusses underlying resistance mechanisms, including alterations in the target enzyme, Cyp51A, and the involvement of efflux pumps in drug efflux. Impact of azole fungicide uses in the environment and the spread of resistant strains is also explored. [ABSTRACT FROM AUTHOR]

Societal Impact Statement: Efficient mitigation of climate change requires predictive models of forest ecosystems as sinks for atmospheric carbon. Mycorrhizal fungi are drivers of soil carbon storage in boreal forests, yet they are typically excluded from ecosystem models, because of a lack of information about their growth and turnover. Closing this knowledge gap could help us better predict future responses to climate change and guide policy decisions for sustainable management of forest ecosystems. This study provides new estimates of the production and turnover of mycorrhizal mycelial biomass and necromass. This information can facilitate the integration of mycorrhizal fungi into new predictive models of boreal forest soils. Summary: In boreal forests, turnover of biomass and necromass of ectomycorrhizal extraradical mycelia (ERM) are important for mediating long‐term carbon storage. However, ectomycorrhizal fungi are usually not considered in ecosystem models, because data for parameterization of ERM dynamics is lacking.Here, we estimated the production and turnover of ERM biomass and necromass across a hemiboreal Pinus sylvestris chronosequence aged 12 to 100 years. Biomass and necromass were quantified in sequentially harvested in‐growth bags, and incubated in the soil for 1–24 month, and Bayesian calibration of mathematical models was applied to arrive at parametric estimates of ERM production and turnover rates of biomass and necromass.Steady states were predicted to be nearly reached after 160 and 390 growing season days, respectively, for biomass and necromass. The related turnover rates varied with 95% credible intervals of 1.7–6.5 and 0.3–2.5 times yr−1, with mode values of 2.9 and 0.9 times yr−1, corresponding to mean residence times of 62 and 205 growing season days.Our results highlight that turnover of necromass is one‐third of biomass. This together with the variability in the estimates can be used to parameterize ecosystem models, to explicitly include ERM dynamics and its impact on mycorrhizal‐derived soil carbon accumulation in boreal forests. [ABSTRACT FROM AUTHOR]

β-Carotene is an attractive compound and that its biotechnological production can be achieved by using engineered Saccharomyces cerevisiae. In a previous study, we developed a technique for the efficient establishment of diverse mutants through the introduction of point and structural mutations into the yeast genome. In this study, we aimed to improve β-carotene production by applying this mutagenesis technique to S. cerevisiae strain that had been genetically engineered for β-carotene production. Point and structural mutations were introduced into β-carotene-producing engineered yeast. The resulting mutants showed higher β-carotene production capacity than the parental strain. The top-performing mutant, HP100_74, produced 37.6 mg/L of β-carotene, a value 1.9 times higher than that of the parental strain (20.1 mg/L). Gene expression analysis confirmed an increased expression of multiple genes in the glycolysis, mevalonate, and β-carotene synthesis pathways. In contrast, expression of ERG9, which functions in the ergosterol pathway competing with β-carotene production, was decreased in the mutant strain. The introduction of point and structural mutations represents a simple yet effective method for achieving mutagenesis in yeasts. This technique is expected to be widely applied in the future to produce chemicals via metabolic engineering of S. cerevisiae. [ABSTRACT FROM AUTHOR]

Botrytis cinerea may cause gray mold in fruits and vegetables. Paeonol, an active component of traditional Chinese medicine, could suppress various microbial growth. However, reports on its effect on B. cinerea have not yet been documented. In this paper, we demonstrated that paeonol completely inhibited B. cinerea growth at 250 mg/L, corroborated by the observation of irregular morphological alterations in B. cinerea exposed to paeonol. Notably, the investigation of the operating mechanism revealed that paeonol induced cell death by disrupting the cell membrane, potentially mediated by the interaction between paeonol and ergosterol from the membrane. Further studies indicated that paeonol decreased ergosterol content and the expression of certain genes involved in ergosterol biosynthesis was significantly downregulated. In addition, paeonol treatment reduced the gray mold of cherry tomatoes. Meanwhile, compared to the control treatment, paeonol treatment could reduce weight loss and maintain higher contents of total soluble solid (TSS) and ascorbic acid, leading to a higher quality of the stored cherry tomato. Together, the data indicate that paeonol was effective as an alternative agent targeting disrupting the cell membrane to control gray mold and prolong the shelf life of cherry tomatoes, suggesting that paeonol could be used as a natural antifungal compound during postharvest storage.

Candida albicans is an opportunistic yeast capable of causing a wide range of mucosal, cutaneous, and systemic infections. However, therapeutic strategies are limited to a few antifungal agents. Inorganic nanoparticles have been investigated as carrier systems for antifungals as potential new treatments. In this study, we focused on the antifungal activity of gold nanorods, a specific rod-shaped gold nanoparticle, produced by green synthesis using resveratrol as a metal-reducing agent. The synthesis method resulted in stable control nanoparticles (AuNp) and resveratrol-coated gold nanoparticles (AuNpRSV) with medium sizes of 32.4 × 15.9 nm for AuNp, and 33.5 × 15.3 nm for AuNpRSV. Both AuNp and AuNpRSV inhibited the C. albicans grown at 2.46 µg/mL, exhibited fungicidal effects at 4.92 µg/mL, and significantly decreased filamentation, biofilm viability, reactive oxygen species production and ergosterol levels of C. albicans. In addition, exposure to AuNpRSV reduced the ability of C. albicans to grow in the presence of cell membrane stressors. Transmission electron microscopy revealed enlargement of the cell wall and retraction of the cell membrane after treatment with AuNp and AuNpRSV. Promisingly, in vivo toxicity analysis demonstrated that both nanoparticles maintained the full viability of Galleria mellonella larvae at 49.20 µg/mL. In conclusion, both gold nanoparticles exhibited antifungal activity; however, these effects were enhanced by AuNpRSV. Altogether, AuNps and AuNpRSVs are potential antifungal agents for the treatment of C. albicans infections.