Genetic Diversity and Dye-Decolorizing Spectrum of Schizophyllum commune Population.

Synthetic dyes are widely used in various industries and their wastage causes severe environmental problems while being hazardous to human health, leading to the need for eco-friendly degradation techniques. The split-gill fungus Schizophyllum commune, which is found worldwide, has the potential to degrade all components of the lignocellulosic biomass and is a candidate for the treatment of synthetic dyes. A systematic molecular analysis of 75 Korean and 6 foreign S. commune strains has revealed the high genetic diversity of this population and its important contribution to the total diversity of S. commune. We examined the dye decolorization ability of this population and revealed 5 excellent strains that strongly decolorized 3 dyes: Crystal Violet, Congo Red and Methylene Blue. Finally, comparison of dye decolorization ability and the phylogenetic identification of these strains generalized their genetic and physiological diversity. This study provides an initial resource for physiological and genetic research projects as well as the bioremediation of textile dyes.

Microbial Glucuronoyl Esterases: 10 Years after Discovery.

A carbohydrate esterase called glucuronoyl esterase (GE) was discovered 10 years ago in a cellulolytic system of the wood-rotting fungus Schizophyllum commune Genes coding for GEs were subsequently found in a number of microbial genomes, and a new family of carbohydrate esterases (CE15) has been established. The multidomain structures of GEs, together with their catalytic properties on artificial substrates and positive effect on enzymatic saccharification of plant biomass, led to the view that the esterases evolved for hydrolysis of the ester linkages between 4-O-methyl-d-glucuronic acid of plant glucuronoxylans and lignin alcohols, one of the crosslinks in the plant cell walls. This idea of the function of GEs is further supported by the effects of cloning of fungal GEs in plants and by very recently reported evidence for changes in the size of isolated lignin-carbohydrate complexes due to uronic acid de-esterification. These facts make GEs interesting candidates for biotechnological applications in plant biomass processing and genetic modification of plants. This article is a brief summary of current knowledge of these relatively recent and unexplored esterases.

Schizophyllum radiatum, an Emerging Fungus from Human Respiratory Tract.

Schizophyllum is an important genus of basidiomycetes that, apart from being of genetic and biotechnological interest, is also reported to be a plant and animal pathogen. Schizophyllum commune is the best-known species and the only one reported from clinical specimens thus far, being recovered mainly from the respiratory tract. The aim of this study was to determine the species diversity of 23 clinical isolates of Schizophyllum from the United States using multilocus phylogenetic analysis and their in vitro susceptibilities to six drugs. The markers used for sequencing were the internal transcribed spacer (ITS), a portion of the nuclear large subunit (LSU) of ribosomal DNA, the RNA polymerase II second-largest subunit (RPB2), and the translation elongation factor 1α (EF-1α) gene. The analyses revealed that 22 of the clinical isolates were in the Schizophyllum radiatum clade with high support values and 1 isolate was in the S. commune clade. This is the first report of this species in clinical samples. The two species mentioned above showed very similar morphological features in culture (i.e., white, cottony, unsporulated colonies composed of hyphae with clamp connections), making morphological discrimination between the two impossible. An epitype is designed for S. radiatum, and its sequences have been deposited in GenBank. The antifungal that showed the greatest in vitro activity against the strains tested was shown to be amphotericin B. In general, the strains of S. radiatum showed higher MICs than S. commune.

Translocation of mercury from substrate to fruit bodies of Panellus stipticus, Psilocybe cubensis, Schizophyllum commune and Stropharia rugosoannulata on oat flakes.

The cultivation and fructification of 15 saprotrophic and wood-rotting fungal strains were tested on three various semi-natural medium. The formation of fruit bodies was observed for Panellus stipticus, Psilocybe cubensis, Schizophyllum commune and Stropharia rugosoannulata in the frame of 1-2 months. Mercury translocation from the substrate to the fruit bodies was then followed in oat flakes medium. Translocation was followed for treatments of 0, 1.25, 2.5, 5, 10 and 20ppm Hg in the substrate. All four fungi formed fruit bodies in almost all replicates. The fruit body yield varied from 0.5 to 15.3g dry weight. The highest bioconcentration factor (BCF) of 2.99 was found for P. cubensis at 1.25ppm Hg. The BCF decreased with increasing Hg concentration in the substrate: 2.49, 0, 2.38, 1.71 and 1.82 for P. stipticus; 3.00, 2.78, 2.48, 1.81 and 2.15 for P. cubensis; 2.47, 1.81, 1.78, 1.07 and 0.96 for S. commune; and 1.96, 1.84, 1.21, 1.71 and 0.96 for S. rugosoannulata. The Hg contents in the fruit bodies reflected the Hg contents in the substrate; the highest contents in the fruit bodies were found in P. cubensis (43.08±7.36ppm Hg) and P. stipticus (36.42±3.39ppm).

On the asymmetry of mating in natural populations of the mushroom fungus Schizophyllum commune.

Before a mycelium of a mushroom-forming basidiomycete develops mushrooms, the monokaryotic mycelium needs to become fertilized. Although the mechanistic details of mating in mushrooms have been studied thoroughly in laboratory research, very little is known on mating patterns in nature. In this study, we performed fine-scale analyses of three populations of Schizophyllum commune from their natural substrate (i.e. dead beech branches). From the three branches, 24, 12, and 24 fruiting bodies were isolated and for each mushroom, the origins of its nuclei and cytoplasm were reconstructed using DNA markers. Nuclear genotypes were determined using sequencing data and mating types, and mitochondrial haplotypes using SNP markers. From these combined data we reconstructed colonization and mating patterns of the mycelia. On each branch, we found multiple dikaryons (3, 3, and 8, respectively); in two instances one nuclear haplotype was shared between two dikaryons and in two other cases a nuclear haplotype was shared between three dikaryons. Each dikaryon always had a single mitochondrial haplotype. These findings indicate that mating usually is not symmetrical and that a monokaryon is most likely fertilized by a small monokaryon, a spore or a dikaryon. Sharing of nuclear haplotype between different dikaryons resulted either from multiple fertilizations of a single monokaryon, if the dikaryons had identical mitochondrial haplotypes, or, if the dikaryons had different mitochondrial haplotypes, most likely from secondary matings between a monokaryon and a dikaryon (Buller phenomenon). We conclude that mating in S. commune between same-sized monokaryons with reciprocal migration, as generally described in textbooks, is rare in nature. We discuss the implications of non-symmetric mating for basidiomycete evolution.

Molecular characterization and in vitro antifungal susceptibility profile of Schizophyllum commune, an emerging basidiomycete in bronchopulmonary mycoses.

Schizophyllum commune (n = 30) showed lowest geometric mean MICs of isavuconazole (0.19 µg/ml), itraconazole (0.2 µg/ml), voriconazole (0.24 µg/ml), and amphotericin B (0.29 µg/ml) and high geometric mean MICs of fluconazole (19.39 µg/ml) and flucytosine (17.28 µg/ml). Five cases (of 8) of allergic bronchopulmonary mycosis that were treated with itraconazole had no recrudescence after 6 to 24 months of follow-up. One case each of invasive pulmonary mycosis and fungal ball were treated successfully with voriconazole and itraconazole.

The α-glucuronidase Agu1 from Schizophyllum commune is a member of a novel glycoside hydrolase family (GH115).

Schizophyllum commune produces an α-glucuronidase that is active on polymeric xylan, while the ascomycete α-glucuronidases are only active on xylan oligomers. In this study, we have identified the gene (agu1) encoding this enzyme and confirmed the functionality by overexpression of the gene in S. commune and degradation of aldopentauronic acids, (MeGlcA)(3)-Xyl(4), in the cultivation medium of the transformants. Expression analysis demonstrated that agu1 is not co-regulated with the predominant xylanase-encoding gene (xynA) of S. commune. The detailed sequence analysis of Agu1 demonstrated that this gene belongs to a novel glycoside hydrolase family (GH115) that also contains candidate genes from ascomycete fungi and bacteria. Phylogenetic analysis showed that the fungal GH115 α-glucuronidases are distinctly separate from the prokaryotic clade and distributed over three branches. The identification of putative genes encoding this enzyme in industrial fungi, such as Aspergillus oryzae and Hypocrea jecorina, will provide a starting point for further analysis of the importance of this enzyme for the hydrolysis of plant biomass.

Pulmonary nodules caused by Schizophyllum commune after cardiac transplantation.

The incidence of pulmonary nodules after cardiac transplantation is not uncommon, and prompt diagnostic procedures are necessary to minimize disease-related morbidity and mortality. We report a 56-year-old woman who was found to have bilateral pulmonary nodules four months after cardiac transplantation. The microorganism was identified with a molecular diagnostic method as Schizophyllum commune, which had not been reported in English literature as a pathogen inducing pulmonary nodules after transplantation. She remained asymptomatic during the therapeutic period and the pulmonary nodules resolved six months later.

Production of schizophyllan using Schizophyllum commune NRCM.

In the present work, four strains were screened for schizophyllan production, of which Schizophyllum commune NRCM was selected for further work. The fermentation was carried out for 168 h at 28+/-2 degrees C on an orbital shaker at 180 rpm. In the first step, one factor-at-a-time method was used to investigate the effect of media constituents such as carbon and nitrogen sources on schizophyllan production. Subsequently in the second step, concentration of the medium components was optimized using Response Surface Method (RSM). The yield increased from 3.25+/-0.72 g/l in the unoptimized media to 8.03+/-1.12 g/l in the medium optimized by RSM.

Fourier transform infrared microscopy and imaging: detection of fungi in wood.

FTIR microscopy was used to detect and discriminate the two wood decaying fungi Trametes versicolor and Schizophyllum commune in experimentally infected beech wood blocks. The distribution of fungal mycelium in wood was locally resolved and semiquantitatively recorded using FTIR microscopy combined with a focal plane array detector and image analysis. Cluster analysis revealed major differences between FTIR spectra recorded from wood fibers and empty vessel lumina and spectra from mycelium of both fungal species, irrespective of whether the fungi were grown on the surface of wood or inside vessel lumina. Species-specific clustering of spectra of fungal mycelium grown on the wood surface and inside vessel lumina demonstrated the potential of FTIR microscopy to discriminate among fungal species decaying wood.

[The basidiomycete Schizophyllum commune in paranasal sinuses]. / Der Basidiomyzet Schizophyllum commune in den Nasennebenhöhlen.

In the last fifty years, only 22 medical cases involving the basidiomycetous fungus Schizophyllum commune were reported. In a period of three years we have examined 270 patients suffering from chronic rhinosinusitis as well as from mycoses (fungus balls) within the paranasal sinuses. Either nasal mucus or fungal concrement from the sinuses were cultured and the resulting cultures identified microscopically. In cases, where a reliable identification of the fungi was not possible, DNA was extracted for molecular examination. The internal transcribed spacer (ITS) region of the ribosomal gene-cluster was amplified with fungus specific primers and sequenced thereafter. In addition, DNA of all fungi growing with sterile white mycelium was amplified with the primer pair scom1/scom2r, which is specific for S. commune. Altogether, within a three years period S. commune was isolated in twelve patients. It can be assumed, that with the presented methods S. commune will be found much more frequently in patients suffering from diseases of the nasal sinuses.

First report on Schizophyllum commune from a dog.

This report describes the first isolation of Schizophyllum commune from a granulomatous lesion on the neck of a dog. The biopsy specimen from the lesion disclosed granulomatous inflammation with branching fungal hyphae without clamp connections. The clinical isolate was identified as S. commune by mycological examination and analysis of ribosomal DNA sequences.

Development of molecular methods for identification of Schizophyllum commune from clinical samples.

In the last 50 years, to our knowledge, only 16 cases of diseases caused by Schizophyllum commune in humans have been reported. Within only 6 months, we found four isolates of this basidiomycetous fungus, obtained from patients suffering from chronic sinusitis. The cultures of the isolated fungi showed neither clamp connections nor fruiting bodies (basidiocarps), which are distinctive features for S. commune, but fast-growing cottony white mycelium only. This was harvested, and DNA was extracted. The internal transcribed spacer region of the ribosomal DNA (rDNA) was amplified with fungus-specific primers, and the PCR products were sequenced. Two strains of S. commune, collected from branches of a European hornbeam (Carpinus betulus) and a tree of heaven (Ailanthus altissima), respectively; four specimens from the herbarium of the Institute of Botany, Karl-Franzens-University Graz; and two strains from internationally known culture collections (CBS 340.81 [ATCC 44201] and CBS 405.96) were investigated in the same way. The sequence data of all strains were compared and showed homology of over 99% in this 660-bp-long fragment of rDNA. With these results, a map of restriction enzyme cutting sites and a primer set specific for S. commune were created for reliable identification of this human pathogenic fungus.

Maxillary sinusitis caused by Schizophyllum commune and experience with treatment.

A case of sinusitis caused by the basidiomycete Schizophyllum commune is reported in a 36-year-old female with a history of allergic rhinitis and dermatitis. The patient presented with sudden nasal obstruction, purulent nasal discharge, headache and general discomfort. Computer tomography revealed extensive opacity of the left maxillary sinus as well as erosion of the nasal wall and maxillary bone. Mycological examinations of nasal discharges and material aspirated during anthrostomy showed hyaline, septate hyphae with rare spicules. Primary isolation yielded a white, woolly mould which demonstrated clamp connections and basidiocarp primordia but these characteristics were lost in subculture. Identification was confirmed by vegetative compatibility studies. The patient was treated with itraconazole to avoid possible postsurgical dissemination. Three months after cessation of therapy, no recurrence of infection had occurred.