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This paper assesses the ability of strains of Aphanoascus fulvescens and Chrysosporium articulatum isolated from soil (phaesol) to degrade native feather keratin. Strains were identified based on phenotypic traits and nucleotide sequencing. Response Surface Methodology was used to optimize cultivation conditions exhibiting the highest keratinolytic activity. The experiments were based on Box-Behnken designs for the loss of substrate mass (chicken feathers). While substrate mass loss is an “economic coefficient” that reliably indicates feather keratin degradation, it has not been studied before. Stationary liquid cultures of five selected strains were conducted in laboratory conditions at 28 °C using poultry feathers (1 g) as the sole source of carbon, nitrogen and energy. Enzymatic activities, keratin mineralization products and substrate mass loss were determined periodically. The mineralization of keratin proteins by strains yielded a high number of ammonium ions alkalinizing the medium. Increased ammonium ions inhibited the activity of caseinian protease and keratinase. A decrease in the concentration of these ions induced proteolytic enzymes, chiefly the activity of keratinase, at the end of fungal cultivation. Keratinase activity was related to protein- and peptide release and that of caseinian protease to sulfate ions. The highest loss of substrate mass in comparison to the reference strain CBS104.62 (35.4%) was recorded for Aphanoascus fulvescens B21/4-5 (65.9%). Based on a Box-Behnken design, the maximum loss of substrate mass for the Aphanoascus fulvescens strain (71.08%) can be achieved at pH 7.58 and temperature 28.7 °C.

In the context of immunologic failure associated with advanced HIV infection, a novel dimorphic fungus in the genus emmonsia is identified as an important cause of human disease. This report describes 13 cases of infection with this organism in Cape Town, South Africa. The human immunodeficiency virus (HIV) pandemic in sub-Saharan Africa has resulted in an epidemic of opportunistic fungal diseases, some of which are caused by new and emerging fungal pathogens. 1 Much remains to be learned about the endemic fungi of sub-Saharan Africa. For example, considerable differences have been noted between the African and North American varieties of Histoplasma capsulatum and Blastomyces dermatitidis . 2 The genus emmonsia contains three species associated with human disease. Emmonsia crescens and Emmonsia parva are the agents of adiaspiromycosis, a pulmonary disease of small mammals and occasionally of humans. 3 Emmonsia pasteuriana infection has been described in a . . .

A biopsy of skin tissue demonstrated small budding yeasts, resembling those of Histoplasma capsulatum, in addition to larger pleomorphic cells. [...]the fungus that grew in culture had a dissimilar microscopic appearance [1, 2]. [...]occurring infections of animals have not been demonstrated [22]. Schwartz and colleagues found that intraperitoneal inoculations with Es. africanus were fatal to wild-type mice at doses of 106 conidia, whereas lower doses did not cause disease (although the organism could still be cultured from their livers and spleens with inoculae as low as 102 conidia) [20]. [...]C57BL/6 mice were more susceptible to disease than BALB/c mice [20]. First report of urease activity in the novel systemic fungal pathogen Emergomyces africanus: A comparison with the neurotrope Cryptococcus neoformans.

Background Dermatophytosis is a common skin infection of cats and many other animals. A reliable diagnosis is crucial because of the zoonotic potential of dermatophytes. The routine mycological diagnostic procedures for dermatophytosis are widely known, but in the case of some isolates, identification based on phenotypic characteristics may be incorrect. Infections caused by Chrysosporium spp. are usually described in reptiles, but in other animals they are uncommon. Case presentation This study presents a description of a cat with dermatological lesions, that was mistakenly diagnosed with Trichophyton spp. dermatophytosis. Clinical material for mycological examination was collected from alopecic areas on the back of the neck, the ventral abdomen, and the hindlimbs. The initial identification based on phenotypic properties indicated Trichophyton spp. The result of the MALDI-ToF MS allowed the exclusion of the Trichophyton genus. Ultimately, the correct identification as Chrysosporium articulatum was obtained based on the sequencing of ribosomal genes. Conclusions Interpretation of the results of the mycological examination of samples collected from animals’ skin or hair shafts is always challenging. Thus, careful consideration of the primary cause of the clinical lesions observed on the skin is mandatory, and the culture results are worth supporting by molecular methods.

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.

When exposed to higher Pb super(2+) concentration, Phanerochaete chrysosporium secreted higher content of oxalate and thiol compounds. An earlier and faster increase in oxalate was observed after short-term exposure, comparing with a gentle increase in the thiol compounds. In the extracellular polymeric substances (EPS) extract, more oxalate and T-SH were detected when the initial Pb super(2+) was higher, and the variations were different from the situation in the culture medium. In EPS solution, the oxalate amount was more closely related with Pb than that of thiol compounds. pH condition in the whole Pb removal process by P. chrysosporium ranged from 4 to 6.5 and was more beneficial for the binding of Pb super(2+) to carboxylic groups in the oxalic acid. More Pb super(2+) induced more EPS amount, and the increase of EPS amount influenced the immobilized oxalate more seriously. The present study can supply more comprehensive information about the metal passivation mechanism in white-rot fungi and provide meaningful references for an enhanced removal of heavy metals.

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.

Background Fungal skin infections associated with Ophidiomyces ophiodiicola , a member of the Chrysosporium anamorph of Nannizziopsis vriesii (CANV) complex, have been linked to an increasing number of cases of snake fungal disease (SFD) in captive snakes around the world and in wild snake populations in eastern North America. The emergence of SFD in both captive and wild situations has led to an increased need for tools to better diagnose and study the disease. Results We developed two TaqMan real-time polymerase chain reaction (PCR) assays to rapidly detect O. ophiodiicola in clinical samples. One assay targets the internal transcribed spacer region (ITS) of the fungal genome while the other targets the more variable intergenic spacer region (IGS). The PCR assays were qualified using skin samples collected from 50 snakes for which O. ophiodiicola had been previously detected by culture, 20 snakes with gross skin lesions suggestive of SFD but which were culture-negative for O. ophiodiicola , and 16 snakes with no clinical signs of infection. Both assays performed equivalently and proved to be more sensitive than traditional culture methods, detecting O. ophiodiicola in 98% of the culture-positive samples and in 40% of the culture-negative snakes that had clinical signs of SFD. In addition, the assays did not cross-react with a panel of 28 fungal species that are closely related to O. ophiodiicola or that commonly occur on the skin of snakes. The assays did, however, indicate that some asymptomatic snakes (~6%) may harbor low levels of the fungus, and that PCR should be paired with histology when a definitive diagnosis is required. Conclusions These assays represent the first published methods to detect O. ophiodiicola by real-time PCR. The ITS assay has great utility for assisting with SFD diagnoses whereas the IGS assay offers a valuable tool for research-based applications.

Efficient lignin depolymerization is unique to the wood decay basidiomycetes, collectively referred to as white rot fungi. Phanerochaete chrysosporium simultaneously degrades lignin and cellulose, whereas the closely related species, Ceriporiopsis subvermispora, also depolymerizes lignin but may do so with relatively little cellulose degradation. To investigate the basis for selective ligninolysis, we conducted comparative genome analysis of C. subvermispora and P. chrysosporium. Genes encoding manganese peroxidase numbered 13 and five in C. subvermispora and P. chrysosporium, respectively. In addition, the C. subvermispora genome contains at least seven genes predicted to encode laccases, whereas the P. chrysosporium genome contains none. We also observed expansion of the number of C. subvermispora desaturase-encoding genes putatively involved in lipid metabolism. Microarray-based transcriptome analysis showed substantial up-regulation of several desaturase and MnP genes in wood-containing medium. MS identified MnP proteins in C. subvermispora culture filtrates, but none in P. chrysosporium cultures. These results support the importance of MnP and a lignin degradation mechanism whereby cleavage of the dominant nonphenolic structures is mediated by lipid peroxidation products. Two C. subvermispora genes were predicted to encode peroxidases structurally similar to P. chrysosporium lignin peroxidase and, following heterologous expression in Escherichia coli, the enzymes were shown to oxidize high redox potential substrates, but not Mn2+. Apart from oxidative lignin degradation, we also examined cellulolytic and hemicellulolytic systems in both fungi. In summary, the C. subvermispora genetic inventory and expression patterns exhibit increased oxidoreductase potential and diminished cellulolytic capability relative to P. chrysosporium.

White rot fungi including Phanerochaete chrysosporium are known for their ability to mineralize plant-derived materials, such as cellulose, hemicellulose, and lignin, into CO 2 and H 2 O. This process is achieved through a diverse array of hydrolytic and oxidative enzymes. However, the mode of action and specific characteristics of lytic polysaccharide monooxygenases (LPMOs) from P. chrysosporium are not well understood. In this study, two auxiliary activity (AA) family 9 genes from P. chrysosporium , PchAA9C and PchAA9F , were heterologously expressed in Pichia pastoris and functionally characterized. The recombinant PchAA9C and PchAA9F exhibited optimal activity at 60 °C and pH 6.0, with their activity significantly enhanced by 0.5–3.0 mmol/L ascorbic acid ( P  < 0.05). Substrate specificity analysis revealed that both PchAA9C and PchAA9F displayed robust activity against Icelandic moss lichenan, phosphoric acid swollen cellulose, and microcrystalline cellulose, indicating a preference for breaking down β-(Glc1 → 4Glc)-linked substrates. Further analysis using HPAEC-PAD and MALDI-TOF-MS revealed that PchAA9C functioned as a C1-specific oxidizing enzyme, whereas PchAA9F targeted both C1 and C4 positions of sugar rings. Synergistic experiments involving an enzyme cocktail of xylanase, glucanase, and pectinase showed that PchAA9C and PchAA9F significantly enhanced the production of reducing sugars from corn and soybean straws. Notably, PchAA9F represents the first reported C1/C4-double-oxidizing LPMO isolated from P. chrysosporium . This discovery provides new insights into the molecular basis of the biodegradation capabilities of wood-decaying fungi and highlights PchAA9F as a promising candidate for applications in lignocellulosic biomass biorefinery. Graphical abstract