Journal of Fungi最新文献

Pseudomonas aeruginosa and Scedosporium/Lomentospora often coexist in the lungs of cystic fibrosis patients, where their interaction can affect disease outcomes. Our group has recently demonstrated that P. aeruginosa suppresses the growth of Scedosporium/Lomentospora species partly through mechanisms involving iron sequestration. In this study, we have investigated how molecules secreted by P. aeruginosa under high (36 µM) and low (3.6 µM) iron conditions affect the planktonic growth and biofilm formation by S. apiospermum, S. minutisporum, S. aurantiacum and L. prolificans. Although P. aeruginosa exhibited enhanced proliferation under high-iron conditions, spectrophotometric analyses revealed a marked increase in phenazine and pyoverdine production under low-iron conditions, with siderophore activity confirmed by Chrome Azurol S assays. Supporting these findings, supernatants from P. aeruginosa cells grown under iron limitation markedly inhibited fungal growth (≈30%) and biofilm formation (≈70%), whereas those from high-iron cultures were less effective. Notably, low-iron bacterial-free supernatants exhibited pronounced cytotoxic effects on mammalian cells, reducing metabolic activity by an average of 20% in A549 lung epithelial cells and 40% in THP-1 macrophages, and significantly compromising survival in the Tenebrio molitor infection model, resulting in 100% larval mortality within 7 days. Collectively, these results indicate that the antifungal activity of P. aeruginosa is closely coupled with increased host toxicity. Moreover, the results demonstrate that environmental iron availability plays a critical role in modulating both antifungal activity and toxicity, thereby shaping P. aeruginosa interactions with Scedosporium/Lomentospora species. Such iron-dependent dynamics may influence the progression and severity of respiratory co-infections, with important implications for patient management and therapeutic interventions.

The Cladia aggregata group of lichen-forming fungi comprises multiple species that are difficult to differentiate based on phenotypic characters. It has a wide distribution across several continents, but is most diverse in Australasia. We aimed to delimit the species complex further, investigate the relatedness of the lineages, and examine their distributional ranges and phenotypic traits. We used Restriction Site Associated DNA Sequencing (RAD-seq) to compare thousands of loci across 91 individuals from the Americas, Asia, and Australasia. All Asian samples formed a distinct, monophyletic clade in all phylogenetic trees, while the American samples divided into two clades, one comprising South American samples and another comprising Caribbean samples, with the latter representing C. aggregata sensu stricto, as the type specimen was collected in Jamaica. Further population-genomic analyses support the conclusion that the Asian samples are genetically distinct and are here described as a new species. The new species, Cladia asiatica, accommodates the Asian samples previously included in C. aggregata. Our analysis highlights the potential of next-generation sequencing to reveal hidden diversity and resolve the phylogeny of this species complex and lichen-forming fungi in general.

Dermatophytes are fungi that infect the human skin and its appendages. With new pathogenic species emerging and resistance to first-line drugs rising, microbiologic diagnosis and species identification are becoming even more important. In this study, the DermaGenius^® 2.0/3.0 Complete multiplex real-time PCR and the EUROArray Dermatomycosis kits were compared to fungal culture and with each other; 78 reference strains and 124 clinical samples were analyzed. Both the DermaGenius^® kit (97%; 95%CI 89-100%) and the EUROArray assay (91%; 95% CI: 82-96%) were sensitive when analyzing on-panel reference strains. In clinical samples, the DermaGenius^® assay provided a positive result in 63 out of 124 (51%) samples and the EUROArray assay in 74 out of 124 (60%) samples. Both kits supported the diagnosis and species identification of culture-negative samples, and samples with growth of unconventional species. However, there was suspicion of false-positive results with F. solani in the EUROArray kit both in clinical and reference strains. The most common conventional dermatophytes in this study combining all methods were T. rubrum/soudanense (n = 40) and T. interdigitale/mentagrophytes (n = 11). In summary, both PCR kits were sensitive for the diagnosis and species identification of dermatophytoses. Combining culture and a PCR-based method can increase the diagnostic yield and compensate for the weakness of the other methods. The optimal PCR-based kit, and especially the optimal panel size, depends on the local epidemiology of dermatophytes.

Plant endophytes, often termed the "second genome", critically shape host adaptability. However, the complexity of their interactions, regulated by microbial traits, host species, and environment, has limited both our understanding of symbiosis and the application of beneficial endophytes. The symbiosis between locoweeds (Oxytropis and Astragalus species) and the endophyte Alternaria sect. Undifilum, which produces the neurotoxin swainsonine, serves as an ideal model for investigating these relationships. Through extensive national surveys (2021-2023) across China's major locoweed habitats, combining field sampling with cultivation, molecular, quantitative, and modeling approaches, a central question emerged: To what extent are the distribution and function of this symbiosis shaped by the contemporary environment versus host evolutionary history? The results showed that: (1) Among 32 surveyed species of Oxytropis, Astragalus, and Sphaerophysa, the endophyte Alternaria sect. Undifilum colonized 11 species. In colonized plants, endophyte loads ranged from 0.02 to 58.87 pg/ng total DNA, and swainsonine concentrations varied from 0.00003% to 1.00%. (2) Environmental factors, rather than host phylogeny, were the key driver governing the geographical distribution and expression of the symbiosis. (3) Low temperature and drought stress regulated the symbiotic relationship and chemical defense through both direct effects on the symbionts and indirect pathways involving grazing pressure. This study demonstrates that the environment is the core force dominating the geographical pattern and functional expression of the locoweed-endophyte symbiosis at ecological scales. These findings provide new perspectives for understanding the general principles of plant-endophyte symbiosis and establish a scientific foundation for predicting and utilizing endophyte resources in changing environments.

Filamentous fungi are widely used in biotechnological processes because they secrete significant amounts of protein, use inexpensive nutrient media, and are predictably scalable in technological processes. Penicillium verruculosum B1-537 (now renamed Talaromyces verruculosus) produces large amounts of secreted protein (up to 70 g/L) and is used for large-scale enzyme production. Although P. verruculosum has an excellent protein expression system under the control of a strong cbh1 promoter, some heterologous enzymes such as Aspergillus awamori glucoamylase (aaGlaA) are still produced in insufficient quantities (15-20% of the total secreted protein), and this limits the application of enzyme preparations derived from P. verruculosum strains in the alcohol industry for the enzymatic treatment of grain starch together with α-amylase. One of the well-known approaches to addressing this is signal peptide replacement to increase protein expression. Therefore, the aim of this study was to investigate the effectiveness of signal peptide replacement. Various signal peptides (SPs), which were previously used for other well-expressed heterologous proteins, such as xylanases, β-glucosidases, and others, were analyzed to determine their effect on aaGlaA secretion. Five plasmids containing signal peptide sequences fused to the glaA gene were constructed and used to transform P. verruculosum. The resulting strains were cultured and screened for protein content and glucoamylase activity. Copy number analysis was performed on the most productive strains. The best one was an SP of homologous glucoamylase in P. verruculosum (pvGlaA). The use of this particular SP increased the secretion of heterologous aaGlaA by 2.5 times when cultivating recombinant strains on cellulose-containing fermentation media for P. verruculosum. Thus, SP replacement is a useful way to increase expression levels in the P. verruculosum expression system. Application of this method in P. verruculosum could address some productivity issues and enable the large-scale production of other industrial and food enzymes.

The phytopathogenic fungus Colletotrichum scovillei causes a destructive anthracnose on pepper fruit worldwide. Conidiation plays an essential role in the dissemination of pathogenic fungi, yet the regulatory mechanisms underlying this process remain largely unknown. In this study, a pheromone-regulated membrane protein 10 (PRM10) was identified in C. scovillei, whose function has not been characterized in fungal plant pathogens previously. The targeted gene deletion mutant (ΔCsprm10) was normal in plant infection but showed a decrease in surface hydrophobicity compared to the wild-type strain. Notably, ΔCsprm10 was completely defective in conidiation. A microscopic observation further confirmed that ΔCsprm10 failed to form conidiophores, suggesting that CsPRM10 plays an essential role in the conidiation of C. scovillei by regulating conidiophore development. The transcriptomic analysis indicated that the loss of CsPRM10 caused differential expressions of genes related to membrane-associated processes and nuclear functions. Taken together, these findings suggest that CsPRM10 acts as a novel regulator of conidiation in C. scovillei and provide new insights into the molecular basis of fungal asexual development.

The genus Picoa is here revisited after obtaining new molecular and morphological data. Morphological features of type material and other historical collections of P. juniperi and P. lefebvrei were studied and compared with recent collections obtained from several European, African, and Asian countries. Genetic studies employing ITS rDNA, as well as 28S rDNA and the RPB2 gene, were conducted on modern samples. As a result, 19 taxa are identified, 17 of which are new to science. Detailed descriptions of all species are provided, including macro- and micro-photographs, and an identification key. The phylogenetic structure of the genus is discussed, and the main clades are described in the following new sections: Picoa sect. Communes, sect. Juniperi, sect. Lefebvreorum, sect. Microsporae, and sect. Puenteorum. Finally, the boundaries of the genus Picoa are evaluated by comparison with the sister genera Geopora, Sepultaria, and Terracavicola.

This study presents a comparative analysis of secondary metabolites and antioxidant, antimicrobial, and anticancer activities of acetone extracts obtained from the lichens Lepraria incana and Pertusaria amara. HPLC-UV analysis identified divaric acid, divaricatinic acid, norstictic acid, divaricatic acid and usnic acid in L. incana, and conprotocetraric acid, protocetraric acid, picrolichenic acid and atranorin in P. amara. Free radical scavenging capacity and reducing power assays were employed to assess the antioxidant activity of the extracts. The IC₅₀ values in the free radical scavenging assay were 664.23 μg/mL for L. incana and 750.50 μg/mL for P. amara, while reducing power absorbances varied between 0.0875-0.2562 and 0.0336-0.2011, respectively. Total phenolic contents in L. incana and P. amara extracts were 40.81 and 33.67 μg PE/mg of extract, while total flavonoid contents were 24.74 and 23.61 μg RE/mg of extract, respectively. Antimicrobial activity, determined by the microdilution method, ranged from 156 to 20 × 10³ μg/mL for L. incana and from 312 to 20 × 10³ μg/mL for P. amara. Cytotoxicity was tested using the MTT method. Among the tested samples, the L. incana extract showed the strongest cytotoxic activity toward A549 cells, with an IC₅₀ value of 47.53 μg/mL. Based on the results, the lichens examined demonstrate promise for future studies and potential development in biopharmaceutical applications.

Drought stress severely limits wheat growth, development and yield. Endophytic fungi play a crucial role in plant growth and drought resistance. In agricultural production, they hold significant application potential as biocontrol agents capable of mitigating drought-induced damage. However, the mechanisms underlying changes in endophytic fungal community structure under drought stress remain unclear. Our study employed amplicon sequencing to investigate the structure of endophytic fungal communities in wheat roots under different water treatments, comparing structural and functional changes between different treatments. Results revealed that drought stress led to the greatest accumulation of relative abundance in the phylum Ascomycota (86.4%). At the genus level, Stachybotrys (increase 994.2%), Fusarium (increase 94.6%) and Aspergillus (increase 295.6%) showed the most significant increases in relative abundance. Co-occurrence network and Sankey diagram analysis revealed that wheat roots formed a drought-specific endophytic fungal community centered around Stachybotrys, Fusarium and Aspergillus, which indirectly enhanced crop drought tolerance. Our findings provide a theoretical foundation for future agricultural strategies to improve crop drought resistance through precise regulation of microbial communities.

Saccharomyces cerevisiae probiotic properties are effective for the treatment of infections by the opportunistic pathogen Candida albicans. Here, we assessed the anti-Candida effect of cell-free supernatants (CFSs) from three different fecal isolates and one ATCC strain of S. cerevisiae. We evaluated C. albicans growth inhibition through CFUs, and the impairment of virulence factors (adhesion, biofilm formation, and metabolic activity) by crystal violet and XTT assays. An untargeted metabolomic analysis of the CFSs was also performed. The CFSs moderately reduced C. albicans growth, but they could impair C. albicans virulence by reducing its capacity to adhere and to form a biofilm, and by decreasing the metabolic activity of biofilm-embedded fungal cells. The untargeted metabolomic analysis indicated an overexpression of N-acetyl-DL-tryptophan and other molecules derived from its metabolism (kynurenic acid and indole-3-acrylic acid), the dipeptides glycyl-L-leucine, prolyl-leucine, and γ-L-glutamyl-L-leucine, and the unconventional nucleotide inosine in the CFSs from fecal isolates, as compared to the reference strain. Further studies are warranted to better characterize the metabolome of these CFSs. Should the effects described here also be confirmed in vivo, the possible future employment of S. cerevisiae CFSs as a postbiotic aid to the current antifungal therapy may be considered.