Investigation into the production of bacteriostatic substances by fungi VI. Examination of the larger Basidiomycetes

The present paper, the sixth of the series, gives the results of testing some 700 species of the larger Basidiomycetes for bacteriostatic properties. Initially, the 'juice' extracted from the sporophore was tested and this was followed in certain cases by a test of the metabolism solution produced by the fungus in culture. The results indicate that the larger Basidiomycetes are among the more promising fungus groups which produce antibiotics and that they compare favourably in this respect with the Aspergilli and the Penicillia. Of the 700 species tested approximately 70 are strongly and approximately 100 weakly positive against Staphylococcus aureus and/or Bacterium colt.     

Organic acids production by white rot Basidiomycetes in the presence of metallic oxides

The purpose of the present work was to determine if selected fungal strains belonging to wood-rotting Basidiomycetes are able to grow on and to solubilize different insoluble oxides in solid media. Twenty-eight strains of white rot fungi were checked for their growth on oxide-amended media (ZnO, CaO, Cu2O). All strains displayed growth on Zn-amended plates but to a different extent, and Cu2O-amended plates turned out to be the most toxic oxide. Most of the tested strains solubilized oxalates and produced noticeable clear zones under the mycelium. These clear zones were tested for the presence of organic acids, the level of which was clearly elevated upon exposure of fungal strains to insoluble oxides. We determined the presence of oxalic, malic, and formic acids, with oxalic acid the predominant one.     

Effects on Tyrosinase Activity by the Extracts of <Emphasis Type="Italic">Ganoderma lucidum</Emphasis> and Related Mushrooms

The inhibitory effects on tyrosinase activity by extracts of several mushrooms belonging to Basidiomycetes were evaluated. Among the tested mushrooms (Ganoderma lucidum, Antrodia camphorata, Agaricus brasiliensis, and Cordyceps militaris), G. lucidum exhibited significant inhibition of tyrosinase activity (IC(50) value 0.32 mg/ml), compared to those prepared from other Basidiomycetes. Tyrosinase inhibitors are effective components of skin-lightening compounds and other cosmetics; currently many of the facial mask cosmetics in the market contain Ganoderma extracts in their ingredients. The finding that mushroom extracts contain tyrosinase activity inhibition will contribute to better understanding of how their 'healing' properties in various Chinese traditional herbal on skin care products.     

高等担子菌的性非亲和性系统和体细胞非亲和性系统在遗传多样性保存中的作用

本文讨论了高等担子菌的个体概念,以及利用性的非亲和性、体细胞非亲和性对于高等担子菌个体的识别,非亲和性系统对于真菌本身在遗传多样性的保存中的作用。担子菌的个体概念对于其生态学研究具有很大的意义,控制担子菌性非亲和性的交配型基因可以作为遗传多样性研究的重要手段。     

A Cladistic Outline of the Eumycota

Abstract— A cladistic classification of fungi determined by a parsimony method with 21 terminal taxa and 51 characters is presented. Outgroup comparison with Oomycetes determined polarity assessments. The group Eumycota, including the traditional taxa Hyphochytriomycetes, Chytridio-mycetes, Zygomycetes, Ascomycetes and Basidiomycetes, is defined by two synapomorphies, molecular weight of 25S RNA, and chitin cell walls. Some groups are supported as monophyletic; Eumycota, Amastigomycota, Dicaryomycotina, Ascomycetes, Protobasidiomycetes, Basidiomycetes, Euascomy-cetidae, Hymenomycetidae and Homobasidiomycetales. The Hyphochytriomycota is the sister group to remaining groups. The Taphrinaceae and Saccharomycetaceae are more closely related to the Basidiomycetes than to any of the ascomycetous groups. In the absence of unique character sets groups such as the Mastigomycotina, Hemiascomycetes, Ustomycetes, Holobasidiomycetes, Heterobasidio-mycetes, Phragmobasidiomycetes and the Teliomycetes cannot be maintained and are abandoned as paraphyletic. Characters and terminal taxa used for the analysis are defined and discussed.     

Antifungal cellobiose lipid secreted by the epiphytic yeast Pseudozyma graminicola

The yeast Pseudozyma graminicola isolated from plants inhibited growth of almost all ascomycetes and basidiomycetes tested (over 270 species of ca. 100 genera) including pathogenic species. This yeast secreted a fungicidal agent, which was identified as a glycolipid composed of cellobiose residue with two O-substituents (acetyl and 3-hydroxycaproic acid) and 2,15,16-trihydroxypalmitic acid. The release of ATP from the glycolipid-treated cells indicated that this glycolipid impaired the permeability of the cytoplasmic membrane. Basidiomycetes were more sensitive to the cellobiose lipid than ascomycetes.     

Necrotrophic mycoparasitism of Botrytis cinerea by cellulolytic and ligninocellulolytic Basidiomycetes

Twenty-six isolates representing 17 species of aphyllophoraceous, wood-decaying Basidiomycetes and five species of agaricoid, turf-borne, thatch-decaying Basidiomycetes were screened for their abilities to degrade cellulose, lignin, and melanin by using colorimetric degradation assays on agar media. Selected ligninocellulolytic Basidiomycetes capable of degrading melanin were screened for antagonism of Botrytis cinerea Per.:Fr. The greatest inhibition of Botrytis colony and hyphal growth in vitro was observed in confrontations with Irpex lacteus (Fr.) Fr., Trametes versicolor (L.:Fr.) Pilat, and Chondrostereum purpureum (Pers.:Fr.) Pouzar. Hyphal interference and necrotrophic mycoparasitism by these ligninocellulolytic Basidiomycetes were recognized microscopically as coagulation and degeneration of Botrytis cytoplasm and as coiling and invasion of hyphae, conidiophores, and conidia, respectively. Sclerotia of B. cinerea were killed and parasitized in agar media, straw mulch, or moist sand infested separately with these three mycoparasites.     

Biotransformations of aryl alkyl sulfides by whole cells of white-rot Basidiomycetes

White-rot Basidiomycetes promoted the oxidation of aromatic pro-chiral sulfides into sulfoxides with good enantioselectivity, conversion and a small production of sulfones. The reactions were carried out using whole cells of Irpex lacteus, Pycnoporus sanguineus, Trichaptum byssogenum, Trametes rigida, Trametes versicolor and Trametes villosa. The enantioselectivity for all the aryl alkyl sulfoxides was in favor of (S)-enantiomers. Oxidation of (phenylpropyl)sulfide produced (S)-(phenylpropyl)sulfoxide with high enantiomeric excess (e.e. ≥99%) by all the Basidiomycetes employed. Basidiomycetes isolated from Brazilian biomes were used as biocatalysts in the oxidation reaction.     

The Colacosomes: New Structures at the Host-parasite Interface of a Mycoparasitic Basidiomycete*

The ultrastructure of mycoparasitic interactions in heterobasidiomycetes is diverse. A previously unknown cell structure, involved in a specific parasitic interaction, is described and illustrated. Cells of the parasite Platygloea peniophorae (Auriculariales s.l., Basidiomycetes) which attach to host cells of Hyphoderma praetermissum (Aphyllophorales, Basidiomycetes) form distinct marginal vesicular bodies with electron-opaque cores and electron transparent sheaths. Finally, the vesicular content projects through the cell wall of the parasite and then interacts with the cell wall of the host. Ontogenetic stages are described and illustrated in detail.     

Ultrastructure of the dikaryotic form ofCyathus bulleri brodie

The fine structure of the dikaryotic form ofCyathus bulleri Brodie was generally found to be similar to that of other hyphal forms of the Basidiomycetes. The nuclear walls were doubled, porous and in some cases connected to the endoplasmic reticulum. The presence of typical as well as filamentous and U-shaped mitochondria was confirmed. Other cellular structures and organelles, among them vacuoles, vesicular and myelinoid-like bodies, often associated with the cell membranes, glycogen and ribosomes were also observed in the cytoplasm. The presence of the dolipore/parenthesome apparatus and clamp connections typical of the Basidiomycetes was established.     

Free-radical scavenging activity of submerged mycelium extracts from higher basidiomycetes mushrooms

Twenty-four Basidiomycetes strains were evaluated to determine their free-radical scavenging capacity in submerged cultivation. The scavenging capacity of the extracts varied from 1 to 85% depending on the mushroom species, solvent used, and concentration. A calculation of EC(50) of extracts from several wood-rotting Basidiomycetes showed high scavenging abilities at low effective concentration.     

Unilateral nuclear migration in Basidiomycetes: pheromone interaction,genomic conflicts and mating-system reversion

Unilateral nuclear migration (UNM) is a striking deviation from the normal reciprocal exchange of nuclei in mating between otherwise compatible monokaryons in Basidiomycetes. UNM has rarely been subject to systematical investigation. Here, we examine the scientific history of UNM in Basidiomycetes and evaluate the explanations brought forward. We suggest that UNM could have an evolutionary role in mating-system reversion from tetrapolarity by assuring a more stable (reciprocal) nuclear migration.     

The potential of Pseudozyma yeastlike epiphytes for the production of heterologous recombinant proteins

Although Basidiomycetes represent the most evolved class of fungi, they have been neglected with regard to recombinant gene expression. In this work, basidiomycetous yeasts belonging to Pseudozyma spp. were studied with respect to their amenability to heterologous protein production. Single plasmid or cotransformation experiments routinely afforded 100 to 200 independent transformants for the two tested species of Pseudozyma. Green fluorescent protein (GFP) was expressed in the correctly folded conformation, as demonstrated by fluorescence microscopy, and hen egg white lysozyme (HEWL) was expressed in its active form, as revealed by its lytic activity on Micrococcus lysodeikticus cells. Protease analysis established that Pseudozyma spp. contained equivalent or less extracellular protease activity than yeasts and far less protease activity than ascomycetous filamentous fungi in similar culture conditions. This proteolytic activity was inhibited by over 97% with a combination of PMSF and Pepstatin A. N-glycosylation patterns of native Pseudozyma flocculosa secreted proteins were comprised of one or a few short glycan chains that possess a classic eukaryotic structure typical of higher fungi and animal cells. This is the first report of a Basidiomycete that possesses multiple intrinsic characteristics necessary for use as a heterologous gene expression system.     

Somatic nuclear division in the sporidia of Ustilago violacea. III. Ultrastructural observations.

The paper provides detailed ultrastructural observations on nuclear division in the smut fungus Ustilago violacea and is based on previous light-microscopic work outlining the division in living and stained cells. The division as in many other Basidiomycetes is not intranuclear, but occurs within a partially disrupted membrane. The division takes place after migration of most of the nucleus into the bud cell, after limited breakdown of the nuclear membrane, and after the formation of a spindle between two spindle-pole bodies (SPB). The remaining part of the nucleus containing the nucleolus is left behind in the parent cell and degenerates there. The SPB, as in other Basidiomycetes, is a dome-shaped relatively structureless body, quite distinct from the flat plaques of many Ascomycetes and the elaborat centrioles of Phycomycetes. The SPB divides shortly before migration into the daughter cell and invariably is located at the apex of the migrating nucleus. Nuclear division is completed when the two masses of chromatin clustered about each of the SPB's are separated as the spindle elongates. One daughter neculeus reforms in the bud and the other is reformed in the mother cell. Cells fixed and stained by conventional light-microscopic methods were examined in the light of the electron-microscopic observations to determine whether these procedures induce artefacts. Aceto-orcein and Giemsa when used cold were found to produce relatively artefact-free preparations. However, previous results in which the cells were warmed gently in these stains are now seen to contain artefacts in the form of contracted chromatinic granules often arranged in chains. These artefacts may provide useful information but clearly they must be interpreted cautiously until the nature of the changes induced by heating are known.     

Molecular architecture of fungal cell walls. An approach by use of fluorescent markers

Fluorescent probes have been applied to analyze the molecular architecture of fungal cell surfaces. Binding patterns of aniline blue and FITC-labeled wheat germ agglutinin (FITC-WGA) elucidated class-specific properties. Aniline-blue-induced fluorescence was distributed over the entire cell walls from Ascomycetes, but was confined to sporangial walls of Zygomocetes, hyphal tips and a few other sites in Basidiomycetes, while no fluorescence was found with sporangia and rhizoids of Chytridiales. FITC-WGA in Zygomycetes and in Ascomycetes was restricted to few sites (e.g. apex of hyphae), in Basidiomycetes and Chytridiales label was evenly associated with the entire surface of hyphal walls, or sporangia and rhizoids. For Oomycetes, Zygomycetes, Ascomycetes, and Basidiomycetes differences in the molecular architecture between apex and hyphal side walls were discerned, although the chemical nature of these differences is distinct for each class. Species specific differences, due to differences in binding patterns of several lectins are not apparent at fungal cell surfaces. The degree of intraspecies variation was found to be larger than interspecies diversification, suggesting changeableness of the molecular architecture of fungal cell walls. This is in contrast to assertions which we made by working on algae. There species-specific lectin binding patterns have been described.     

Tree communities and soil properties influence fungal community assembly in neotropical forests

The influence exerted by tree communities, topography, and soil chemistry on the assembly of macrofungal communities remains poorly understood, especially in highly diverse tropical forests. Here, we used a large dataset that combines inventories of macrofungal Basidiomycetes fruiting bodies, tree species composition, and measurements for 16 soil physicochemical parameters, collected in 34 plots located in four sites of lowland rain forests in French Guiana. Plots were established on three different topographical conditions: hilltop, slope, and seasonally flooded soils. We found hyperdiverse Basidiomycetes communities, mainly comprising members of Agaricales and Polyporales. Phosphorus, clay contents, and base saturation in soils strongly varied across plots and shaped the richness and composition of tree communities. The latter composition explained 23% of the variation in the composition of macrofungal communities, probably through high heterogeneity of the litter chemistry and selective effects of biotic interactions. The high local heterogeneity of habitats influenced the distribution of both macrofungi and trees, as a result of diversed local soil hydromorphic conditions associated with contrasting soil chemistry. This first regional study across habitats of French Guiana forests revealed new niches for macrofungi, such as ectomycorrhizal ones, and illustrates how macrofungi inventories are still paramount to can be to understand the processes at work in the tropics. Abstract in Spanish is available with online material.     

Molecular weights of the ribosomal ribonucleic acid of fungi

Summary The molecular weights of the 18s and 25s ribosomal RNA components of fungi from all major classes were determined by electrophoresis in polyacrylamide gels. The molecular weight of the 18s RNA was found to be very similar for all fungi (range 0.71–0.75 million) and about 4–5% larger than the 18s RNA of HeLa cells and soybean. The molecular weight of the 25s RNA ranged between 1.45 million in the Myxomycetes and 1.30–1.31 million in the Ascomycetes and Basidiomycetes. The differences in the 25s RNA molecular weights between various classes of fungi were interpreted as being in agreement with a monophyletic origin of the Chytridiomycetes, Zygomycetes, Ascomycetes and Basidiomycetes, and independent origins for the Myxomycetes and the Oomycetes. The Hyphochytridiomycete examined could not be placed unequivocally in any group on the basis of its 25s RNA. Fungal RNA extracted with a p-aminosalicylate-triisopropylnaphthalene sulfonate-phenol mixture at 40–60°C contained a high molecular weight aggregate of the 18s and 25s ribosomal RNA; this suggested significant base sequence homology between the two ribosomal RNA species in fungi.     

Amplification of soil fungal community DNA using the ITS86F and ITS4 primers

Internal transcribed spacer (ITS) 86F and ITS4 and the ITS1-F and ITS86R primer pairs were tested to specifically amplify fungal community DNA extracted from soil. Libraries were constructed from PCR-amplified fragments, sequenced and compared against sequences deposited in GenBank. The results confirmed that the ITS86F and ITS4 primer pair was selectively specific for the Ascomycetes, Basidiomycetes and Zygomycetes fungal clades. Amplified products generated by the ITS1F and ITS86R primer pair also aligned with sequences from a range of species within the Ascomycete and Basidiomycete clades but not from the Zygomycete. Both primer sets demonstrated fungal specificity and appear to be well suited for rapid PCR-based (fingerprinting) analysis of environmental fungal community DNA. This is the first reported use and assessment of the ITS86F and ITS4 and the ITS1-F and ITS86R primer pairs in amplifying fungal community DNA from soil.     

Studies on the Oxidation of Steroids by Fungi

As a result of seeking for suitable microorganisms which catalize the hydroxylation of steroids at C-11 position, Corticium sasakii, the fungus of sheath spot disease of rice, was found among the culture specimens of 28 genera of Basidiomycetes. This organism converted Reich-stein’s compound S to hydrocortisone, epi-hydrocortisone and 17α, 19-dihydroxydesoxycorticosterone.