Mycobiology最新文献

Aspergillus flavus produces aflatoxin B1, a Group 1 carcinogen that causes severe economic and agricultural losses and can lead to invasive aspergillosis in humans. During its growth, A. flavus develops hyphae that form a continuous mycelium, which is associated with host colonization and toxin production. Transcription factors are considered regulators of fungal development and pathogenicity. Among these families, bZIP proteins are associated with growth, metabolism, and stress tolerance. In A. fumigatus, the bZIP transcription factor ZipD regulates calcium signaling pathways and cell wall integrity. However, the ortholog of zipD in A. flavus has not been characterized. To address this gap, we generated a deletion mutant and a complemented strain of zipD in A. flavus. The zipD deletion mutant showed reduced colony growth and conidia production, but increased sclerotia formation. The ΔzipD strain exhibited hypersensitivity to osmotic stress-related agents, cell wall stress-related agents, and high calcium concentrations. Additionally, ΔzipD showed reduced conidial colonization in pathogenicity assays using corn, soybean, and soybean brick compared to the wild-type strain. All of these phenotypes were restored in the complemented strain. These results suggest that zipD functions as a regulator of growth, developmental processes, and pathogenic traits in A. flavus.

This paper documents 17 newly recorded species belonging to the orders Eurotiales, Hypocreales, Pleosporales, Venturiales, and Wallemiales. These species were obtained from freshwater, brackish water, and soil habitats and identified using phenotypic techniques combined with DNA sequence data. Two species belonged to the order Eurotiales (Talaromyces calidominioluteus, and T. endophyticus); two species belonged to the order Hypocreales (Parasarocladium wereldwijsianum, and Simplicillium lamellicola); 11 species belonged to the order Pleosporales (Allophoma tropica, Alternaria longxiensis, Anteaglonium parvulum, Camarosporomyces flavigenus, Edenia achyranthi, Hongkongmyces thailandicus, Periconia imperatae, Pseudopithomyces pavgii, Septoriella huberti, Spegazzinia tessarthra, and Torula chiangmaiensis); one species belonged to the order Venturiales (Scolecobasidium terrestre); and one species belonged to the order Wallemiales (Wallemia mellicola). Detailed descriptions, illustrations, and phylogenetic analysis results of these species have been provided.

Phanerochaete is one of the largest genera of the family Phanerochaetaceae within the order Polyporales, characterized by membranaceous basidiome and ellipsoid to cylindrical basidiospores. As white-rot saprotrophs, Phanerochaete species produce ligninolytic enzymes to degrade lignin and cellulosic materials. Several species have been applied to bioremediation, biopulping, and bioethanol industries due to their enzymatic abilities. While 123 Phanerochaete species have been reported globally, only 13 have been identified in Korea. To narrow this gap, we conducted a nationwide collection of specimens from 2008 to 2024. Subsequently, a comprehensive morphological and multi-marker phylogenetic analyses were performed using the nuclear ribosomal internal transcribed spacer (ITS) and nuclear large subunit ribosomal DNA (nLSU) regions. From 17 specimens, nine unrecorded Phanerochaete species were identified, namely P. albocremea, P. australis, P. cystidiata, P. fusca, P. parmastoi, P. porostereoides, P. rhizomorpha, P. subcarnosa, and P. taiwaniana. This study contributes to expand the known diversity of Phanerochaete in Korea, elucidating the morphological features and phylogenetic relationships of these previously unrecorded species.

Ergosterol (EG), the main bioactive ingredient in Wolfiporia hoelen, has been shown to suppress inflammation and oxidative stress in various disease models. However, the effects of EG on endoplasmic reticulum (ER) stress and apoptosis in tenocytes in in vitro obesity models have not been studied. Protein expression in tenocytes was assessed by Western blotting. Terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) staining was performed to distinguish apoptotic cells, and ELISA was conducted to quantify the protein content in the tenocyte culture medium. The autophagosomes were visualized as punctate structures via monodansylcadaverine (MDC) staining. In this study, we found that treatment with EG prevented apoptosis, collagen degradation, and ER stress and enhanced cell migration in tenocytes treated with palmitate. EG treatment augmented peroxisome proliferator-activated receptor delta (PPARδ) expression and the expression of autophagy markers. PPARδ small interfering RNA (siRNA) or 3-methyladenine, an autophagy inhibitor, abolished the effects of EG on palmitate-mediated tenocyte dysfunction. Interleukin 15 (IL-15) and meteorin-like protein (METRNL) from C2C12 myocytes treated with EG also ameliorated tenocyte injury caused by palmitate. Collectively, our findings suggest that EG exerts protective effects against palmitate-induced metabolic stress in tendinopathy by alleviating ER stress through the PPARδ/autophagy axis and enhancing IL-15- and METRNL-mediated muscle-tendon crosstalk, supporting its potential as a natural compound-based therapeutic candidate.

White-rot basidiomycetes in the family Polyporaceae are important decomposers of lignocellulosic biomass in forest ecosystems and are recognized for their potential in industrial applications. Here, we report the draft genome sequences of Lentinus arcularius, Polyporus parvovarius, and Trametes suaveolens, isolated from South Korea. Using PacBio and Illumina sequencing, we obtained hybrid genome assemblies ranging from 37.8 to 57.9 Mb, with GC contents of 51.7-57.7% and completeness values of 97.4-99.0% (BUSCO, Fungi dataset). Gene prediction revealed 13,374-19,374 protein-coding genes per genome. Functional annotation identified a wide array of carbohydrate-active enzymes and biosynthetic gene clusters. Our findings expand the genomic resources for Lentinus, Polyporus, and Trametes, providing new insights into their lignocellulose-degrading capacity and bioactive metabolite potentials.

Global warming is a major driver of ecological change, yet its impacts on bioindicators such as lichens remain unclear. Lichens, formed by symbiotic associations between fungi and photosynthetic partners, are widely used to assess environmental conditions. However, studies relying on traditional physiological measures, including chlorophyll content and photosynthetic activity, have reported inconsistent responses to climate change. We hypothesized that short-term exposure of lichens to elevated temperatures would not alter these conventional physiological traits but might instead lead to changes in their associated microbiomes. Using a field transplant experiment, we exposed lichens to higher temperature environments and assessed both physiological and microbiome responses. Chlorophyll content and tissue damage showed no significant differences between control and warmed conditions. In contrast, high-throughput sequencing of 16S and ITS regions revealed pronounced shifts in microbial communities. Fungal assemblages exhibited marked declines in alpha diversity, co-occurrence network complexity, and stability of the core microbiome. By comparison, bacterial communities demonstrated greater resilience. Notably, the black yeast Cutaneotrichosporon debeurmannianum became dominant in high-temperature environments. Our findings show that while traditional physiological traits of lichens remain stable under short-term warming, their fungal microbiomes are highly sensitive to thermal stress. We identify fungal community structure-particularly the presence of C. debeurmannianum-as a promising indicator of climate change. These results highlight the importance of considering microbial symbionts when evaluating the ecological responses of lichens to global warming.

Within the order Polyporales, the genus Laetiporus includes brown rot-causing basidiomycetes, popularly known as "chicken of the woods" or "crab of the woods." While these fungi hold significant edible and medicinal value, comprehensive molecular and biochemical investigations of native Korean populations are limited. In this study, we investigated the phylogenetic relationships and nutritional profiles of wild Laetiporus strains collected in Korea. Phylogenetic analysis of ITS sequences from 21 wild strains and 39 previously reported specimens found in Korea confirmed that L. versisporus and L. cremeiporus are the predominant native species in Korea, rather than L. sulphureus as previously documented. Nutritional evaluation revealed protein content in L. versisporus was 11.3% while that in L. cremeiporus was in the range 9.1-18.5% (average 14.5%). Free amino acid profiling showed that, except for cysteine, which was not analyzed, all essential amino acids were present in L. cremeiporus. In L. versisporus, all essential amino acids were detected except for methionine. Glucan analysis demonstrated substantial β-glucan contents, with L. versisporus exhibiting 25.7% and L. cremeiporus strains ranging from 15.1% to 34.8%. Total glucan content reached up to 40.7% in L. versisporus and 39.3% in certain L. cremeiporus strains. These findings would enhance taxonomic understanding of Laetiporus in Korea and establish the nutritional potential of Laetiporus as functional food ingredients and alternative protein sources.

Heat stress induces oxidative stress in Pleurotus ostreatus (P. ostreatus), inhibiting the growth of both mycelium and fruiting bodies. While various studies have analyzed the physiological responses of P. ostreatus under heat stress conditions, comprehensive research comparing physiological responses in mycelium and fruiting bodies through metabolomic analysis of volatile organic compounds has not been conducted. In this study, we invested the levels of volatile organic compounds (VOCs), the activity of VOC synthesis-related enzymes, and the expression of heat resistance-related genes in mycelium and fruiting bodies exposed to heat stress. The total VOC levels measured in mycelium increased, whereas those in fruiting bodies decreased, indicating contrasting responses. In fruiting bodies, following heat stress, the synthesis of 1-Octen-3-ol was inhibited by glutathione peroxidase (GPx), and its conversion to 3-Octanone was accelerated by alcohol dehydrogenase (ADH), resulting in a significant decrease in 1-Octen-3-ol levels. In mycelium, both GPx gene expression levels and ADH activity remained unchanged under heat stress conditions, and 1-Octen-3-ol levels did not decrease. Comparison of heat resistance-related gene expression through quantitative PCR revealed that in mycelium, the expression of genes related to trehalose and heat shock proteins increased, while in fruiting bodies, the expression of genes related to antioxidant enzymes, including GPx, increased. In conclusion, we identified distinct heat resistance responses in mycelium and fruiting bodies, which had different effects on VOC synthesis, leading to contrasting changes.

Highland potato areas in East Java, Indonesia-Sumber Brantas and Tosari-face severe late blight caused by Phytophthora infestans. We profiled phyllosphere fungal communities (phylloplane plus leaf endosphere) on symptomatic potato leaves and examined how management contexts may relate to these assemblages. Leaves from "Granola Lembang" (Sumber Brantas) and "Granola Kembang" (Tosari) were analyzed using ITS amplicon sequencing (Nanopore) and Fourier-transform infrared (FTIR) spectroscopy. After normalization to relative abundances, α-diversity (Observed OTUs, Chao1, Shannon, Simpson) was higher in Tosari; communities were dominated by Ascomycota (putative endophytes/saprotrophs), whereas Sumber Brantas showed lower overall diversity with higher Mucoromycota. PCA of FTIR spectra separated samples by site, consistent with cross-site biochemical differences; however, we do not infer that FTIR differences are caused by community composition, nor that management variables are causal drivers. Instead, we treat management as contextual information that co-occurs with site, cultivar, and environmental/soil differences. Causal inference is not warranted given the two-site observational design, symptomatic-leaf sampling, different cultivars, and limited replication. Within these constraints, our integrative profiling provides hypothesis-generating baselines and suggests that management compatible with reduced chemical inputs may be associated with richer phyllosphere assemblages of potential biocontrol relevance in Indonesian highlands.

Penicillium crustosum and Penicillium solitum are common molds known for their ability to thrive at cool temperatures and low water activities. They are frequently associated with the contamination of cheeses, pome fruits, and meats. While many strains of these species are recognized for producing bioactive metabolites, their volatile metabolism remains poorly understood. In this study, a comprehensive gas chromatography-mass spectrometry (GC-MS) was employed to identify and analyze the volatile organic compounds (VOCs) emitted by P. crustosum strain G10 and P. solitum SA. When cultivated on laboratory media, a total of 25 distinct VOCs were identified from P. crustosum G10, and 17 from P. solitum SA. The VOCs produced by G10 were classified into six categories based on their functional groups: alcohols (four compounds), nitriles (three compounds), alkenes (four compounds), ketones (two compounds), esters (five compounds), and alkanes (three compounds). Notably, several of these VOCs have known biological activities. For instance, 2-tetradecanol and benzyl nitrile have been developed as environmentally safe pest control agents; (E)-5-eicosene exhibits anticancer function; and 4-acetylphenoxyacetic acid shows potential for the inhibition of HIV. Additionally, (Z)-7-hexadecene, octadecanal, and 5-dodecyldihydro-2(3H)-furanone are recognized as insect volatile pheromones. The VOCs from P. solitum SA were grouped into four main categories: alcoholic compounds (two VOCs), aromatic compounds (four VOCs), esters (three VOCs), and alkene compounds (three VOCs). The discussion of these compounds' potential applications offers new perspectives on their future utilization.