Four new Keratinophyton species (Ascomycota, Pezizomycotina, Onygenales), K. gollerae, K. lemmensii, K. straussii, and K. wagneri, isolated from soil samples originating from Europe (Austria, Italy, and Slovakia) are described and illustrated. The new taxa are well supported by phylogenetic analysis of the internal transcribed spacer region (ITS) region, the combined data analysis of ITS and the nuclear large subunit (LSU) rDNA, and their phenotype. Based on ITS phylogeny, within the Keratinophyton clade, K. lemmensii is clustered with K. durum, K. hubeiense, K. submersum, and K. siglerae, while K. gollerae, K. straussii and K. wagneri are resolved in a separate terminal cluster. All four new species can be well distinguished from other species in the genus based on phenotype characteristics alone. Ten new combinations are proposed for Chrysosporium species which are resolved in the monophyletic Keratinophyton clade. A new key to the recognized species is provided herein.

In this study, a modified fir barks (MFB) was prepared by mixing fir barks (FB) and white-rot fungi (Phanerodontia chrysosporium) under aerobic fermentation. The potential of MFB for Cd2+ adsorption was investigated by batch experiments combined with kinetic, isotherm, and thermodynamics analyses. The results revealed that the modification greatly increased the porous structures on the surfaces of fir barks and the surface area of MFB was much higher than that of FB. As a result, the adsorption capacity of Cd2+ on MFB (17.4 mg g-1) was more than two times higher than that on FB (7.2 mg g-1), and the adsorption of Cd2+ on MFB was controlled by physisorption and chemisorption. The immobilization of Cd by MFB in a contaminated agricultural soil was also investigated. The effect of MFB on the bioavailability of Cd was investigated using a leaching test (the European standard EN 12457-2) combined with a typical sequential extraction procedure (the community bureau of reference, BCR). The experimental results showed that the Cd leachability was reduced by 71% when the added MFB dosage was 30 mg g-1. Besides, the MFB amendment could transform Cd from unstable geochemical fractions into more stable fractions. In total, the MFB, as a chemical-free and eco-friendly material, could be potentially employed for in-situ remediation of Cd-contaminated agricultural soils.

Lesions of adiaspiromycosis, a respiratory disease affecting wild animals, have been found mainly in dead mammals and free-living mammals captured for surveillance. No report has described an investigation of adiaspore formation progress in the lung. After establishing an experimental mouse model of intratracheal adiaspiromycosis infection with the causative agent Emmonsia crescens, we observed adiaspore development. The spores grew and reached a plateau of growth at 70 days post-infection. The median adiaspore diameter showed a plateau of around 40 μm. The characteristic three-layer cell-wall structure of adiaspores was observed in the lung at 70 days post-infection. We examined infection with a few spores, which revealed that adiaspores in the mouse lung progressed from intratracheal infection of at least 400 spores. Moreover, we developed adiaspores in vitro by culture in fetal bovine serum. Although most spores broke, some large spores were intact. They reached about 50 μm diameter. Thick cell walls and dense granules were found as common points between in vitro adiaspores and in vivo adiaspores. These models are expected to be useful for additional investigations of E. crescens adiaspores and adiaspiromycosis.

Emmonsia crescens is known as an environmental pathogen causing adiaspiromycosis in small rodents. As the generic name Emmonsia is no longer available for this species, its taxonomic position is re-evaluated. The intraspecific variation of Emmonsia crescens was analyzed using molecular, morphological, and physiological data, and the relationship between frequency of adiaspiromycosis and body temperature of host animals was explored. A North American and a pan-global lineage could be discerned, each with subclusters at low genetic distance. European strains produced the classical type of very large adiaspores, while in the North American lineage adiaspores relatively small, resembling the broad-based budding cells of Blastomyces. Members of the closely related genus Emergomyces may exhibit large, broad-based in addition to small, narrow-based budding cells. We conclude that the morphology of the pathogenic phase in these fungi differs gradationally between species and even populations, and is therefore less suitable as a diagnostic criterion for generic delimitation. Two Emmonsia species are reclassified in Emergomyces.

The biaryl scaffold, often showing axial chirality, is a common feature of various fungal natural products. Their biosynthesis requires an oxidative phenol-coupling reaction usually catalyzed by laccases, cytochrome P450 enzymes, or peroxidases. The combination of a laccase and a fasciclin domain-containing (fas) protein is encoded in many biosynthetic gene clusters of biaryls from ascomycetes. However, such phenol-coupling systems including their regio- and stereoselectivity have not been characterized so far. Elucidating the biosynthesis of the antiparasitic binaphthalene sporandol from Chrysosporium merdarium, we demonstrate the combination of a laccase and a fas protein to be crucial for the dimerization reaction. Only the heterologous coproduction of the laccase and the fas protein led to a functional phenol-coupling system, whereas the laccase alone showed no coupling activity. Thus, the laccase/fas protein combination forms an independent group of phenol-coupling enzymes that determines the coupling activity and selectivity of the reaction concurrently and applies to the biosynthesis of many fungal natural products with a biaryl scaffold.

Influence of water content on the expression of lignocellulolytic enzymes by Phanerochaete chrysosporium remains unclear. This work compares the enzyme production profiles of P. chrysosporium during solid-state and submerged fermentation. There were 110 and 64 extracellular carbohydrate-active enzymes identified in solid-state and submerged fermentation respectively, among which 57 enzymes were common to both of the secretomes. P. chrysosporium secreted more cellulases (especially lytic polysaccharide monooxygenase) and hemicellulases during solid-state fermentation while the proportion of enzyme containing carbohydrate-binding module was higher for submerged fermentation. Although its activities were weaker, the enzyme cocktail from submerged fermentation was surprisingly more effective in hydrolysis at low substrate loading. This advantage of enzymes from submerged fermentation was mainly attributed to carbohydrate-binding module because more xylanases bound with substrate at the beginning of hydrolysis. These results reveal the influence of fermentation conditions on enzyme produced by P. chrysosporium for the first time and show the importance of carbohydrate-binding module in the hydrolysis process of lignocellulose.

Chemical analysis of the fungus Chrysosporium sp. CMB-F294 isolated from the gastrointestinal tract of a market-purchased specimen of Mugil mullet yielded eight new alkaloids, belonging to a rare class of phenylpropanoid piperazines. Chrysosporazines F-M (1-8) occur as an equilibrium mixture of acetamide rotamers and feature unprecedented carbocyclic and heterocyclic scaffolds. Structures inclusive of absolute configuration were assigned by detailed spectroscopic analysis, supported by biosynthetic considerations. Structure-activity relationship studies determined that selected chrysosporazines were promising noncytotoxic inhibitors of the multidrug resistance efflux pump P-glycoprotein (P-gp), capable of reversing doxorubicin resistance in P-gp-overexpressing human colon carcinoma cells (SW620 Ad300). Chrysosporazine F (1) was particularly noteworthy, with a 2.5 μM cotreatment inducing a doxorubicin gain in sensitivity (GS 14) > 2-fold that of the positive control verapamil (GS 6.1).

The gut microbiota of insects is composed of a wide range of microorganisms which produce bioactive compounds that protect their host from pathogenic attack. In the present study, we isolate and identify the fungus Chrysosporium multifidum from the gut of Hermetia illucens larvae. Extract from C. multifidum culture broth supernatant showed moderate activity against a strain of methicillin-resistant Staphylococcus aureus (MRSA). Bioguided isolation of the extract resulted in the characterization of six α-pyrone derivatives (1-6) and one diketopiperazine (7). Of these compounds, 5,6-dihydro-4-methoxy-6-(1-oxopentyl)-2H-pyran-2-one (4) showed the greatest activity (IC50 = 11.4 ± 0.7 μg/mL and MIC = 62.5 μg/mL) against MRSA.

The fungi Chrysosporium lobatum TM-237-S5 was isolated from the sponge Acanthella cavernosa, collected from the mesophotic coral ecosystem of the Red Sea. The strain was cultivated on a potato dextrose agar (PDA) medium, coupling solid-state fermentation and solid-state extraction (SSF/SSE) with a neutral macroreticular polymeric adsorbent XAD Amberlite resin (AMBERLITE XAD1600N). The SSF/SSE lead to high chemodiversity and productivity compared to classical submerged cultivation. Ten phenalenone related compounds were isolated and fully characterized by one-dimensional and two-dimensional NMR and HRMS. Among them, four were found to be new compounds corresponding to isoconiolactone, (-)-peniciphenalenin F, (+)-8-hydroxyscleroderodin, and (+)-8-hydroxysclerodin. It is concluded that SSF/SSE is a powerful strategy, opening a new era for the exploitation of microbial secondary metabolites.

Chemical analysis of Chrysosporium sp. CMB-F214, yielded five new piperazines, chrysosporazines A-E (1-5), with structures assigned by spectroscopic and X-ray analyses and biosynthetic considerations. The chrysosporazines 2-5 exist as an equilibrium of major and minor N-acyl rotamers, while 1-3 incorporate an unprecedented hexahydro-6H-pyrazino[1,2-b]isoquinolin-6-one scaffold. The noncytotoxic chrysosporazines reverse doxorubicin drug resistance in P-glycoprotein overexpressing colon carcinoma cells (SW620 Ad300), with 2 delivering a comparable gain in sensitivity to the positive control, verapamil.