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PubMed2003

[Filamentous fungi and mycotoxins as potential occupational risk factors among farmers harvesting various crops].

The studies to determine the level of filamentous fungi and mycotoxins were carried out in samples of grain and grain dust during threshing of cereals by a combine harvester. High concentration of fungi was noted in grain and grain dust samples, it ranged from 5.0 to 520.0 cfu/g.10(3) and from 275.0 to 2825.0 cfu/g.10(3), respectively Allergizing and toxigenic fungi of Alternaria, Geotrichum, Cladosporium, Penicillium, Aspergillus and Fusarium species were observed in the study samples of grain and grain dust. In the samples of wheat grain, mycotoxins were also noted: moniliformin (MON), deoxynivalenol (DON) and ochratoxin A (OTA); their concentrations ranged from 0.025 to 0.088 microgram/g; 0.015-0.068 microgram/g; and from 0.0004 to 0.0008 microgram/g, respectively. The level of mycotoxins in the grain dust samples was within the range of 0.025-0.149 microgram/g-MON; 0.015-0.215 microgram/g-DON; 0.015-0.360 microgram/g-NIV; and 0.0004-0.0012 microgram/g-OTA. A significant correlation was observed between the occurrence of fungi of Fusarium species and the concentration of pathologic mycotoxins. The results confirm a considerable occupational risk among farmers engaged in grain threshing due to inhalation of pathogenic species of filamentous fungi and mycotoxins.

Agricultural Workers' Diseases↗

PubMedDate not supplied

The influence of detergents and active components of detergent on bioproduction of organic matters and enzymatic activity of some species of fungi.

Detergent (Merix, "Merima " Krusevac) applied in concentration of 1% vol. showed specific influence on the bioproduction of some 15 different amino acids and on the enzyme activity of the species of fungi A. niger, A. alternata and T. roseum. Detergent has significantly stimulated the production of 15 analyzed amino acids of the fungi species A. niger. The same applied concentration of detergent has decreased or considerably decreased the production of some 14 of totally 15 analyzed amino acids of investigated fungi species A. alternata and T. roseum. The enzyme activity of the fungi A. niger was more intensive in relation to the species A. alternata and T. roseum during the experimental period or in some phases of the experimental period. The detergent component, ethoxyled oleyl-cetyl alcohol, in concentration of 0.01%, 0.1% and 1% showed an inhibitory effect, or significant inhibitory effect on the enzyme activity of the examined species of fungi (A. niger, A. alternata and T. roseum).

Alternaria↗

PubMed2004

[A preliminary study on wood-inhabiting fungi on charred wood in Daxinganling forest areas].

Study on wood-inhabiting fungi is one of the active fields of mycology during past 30 years in China, and the study mostly focused on natural forest without fire disturbing. Forest fire changes forest ecology dramatically, and the fungi on charred wood are different from those in nature forests without fires. In this paper, we focused on the wood-inhabiting fungi growing on charred wood in Daxinganling forest areas. Seventeen species were reported: Antrodia sp., Antrodia rantha, Ceriporiopsis mucida, Diplomitoporus lindbladii, Gloeophyllum carbonarium, Gloeophyllum sepiarium, Gloeoporus taricola, Laurilia sulcata, Oligoporus sericeomollis, Phellinus igniarius, Postia caesia, Postia leucomallella, Postia tephroleuca, Schizopora flavipora, Skeletocutis ochroalba, Skeletocutis vulgaris, and Trichaptum fuscoviolaceum. Among them, eight species caused brown rot, and nine species caused white rot. Based on our field studies, eight species were pioneer fungi in charred wood, four species were common one, and three species were rare or threatened in the studied area. Setting up nature reserve should be the best way to protect the rare or threatened species of wood-inhabiting fungi.

China↗

PubMedDate not supplied

[The effect of hydrogen peroxide on the growth of microscopic mycelial fungi isolated from habitats with different levels of radioactive contamination].

The effect of hydrogen peroxide ( 10(-9)-10(-1) M) on the mycelial growth of the fungi Alternaria alternata, Cladosporium cladosporioides, Mucor hiemalis, and Paecilomyces lilacinus has been studied. The growth of fungi isolated from habitats with a background level of radioactive contamination was stopped by H2O2 concentrations equal to 10(-3) and 10(-2) M, whereas the growth of fungi that were isolated from habitats with high levels of radioactive contamination was only arrested by 10(-1) M H2O2. The response of the different fungi to hydrogen peroxide was of three types: (1) a constant growth rate of fungal hyphae at H2O2 concentrations between 10(-9) and 10(-4) M and a decrease in this rate at 10(-3) M H2O2, (2) a gradual decrease in the growth rate as the H2O2 concentration was increased, and (3) an increase in the growth rate as the H2O2 concentration was increased from 10(-7) to 10(2)-5 M. The melanin-containing species A. alternata and C. cladosporioides exhibited all three types of growth response to hydrogen peroxide, whereas the light-pigmented species M. hiemalis and P. lilacinus showed only the first type of growth response. A concentration of hydrogen peroxide equal to 10(-1) M was found to be lethal to all of the fungi studied. The most resistant to hydrogen peroxide was found to be the strain A. alternata 56, isolated from the exclusion zone of the Chernobyl Nuclear Power Plant.

Chernobyl Nuclear Accident↗

PubMed1991

[Keratinophilic fungi in waste water sediments].

In 21 samples of various kinds of waste water sediments derived from 10 waste water treatment plants of Upper Silesia, the occurrence of keratinophilic fungi was examined. A 2-year recultivation cycle of one of the sediments was investigated. Keratinophilic fungi were found to occur abundantly in waste water sediments. The qualitative and quantitative composition of these fungi depends on the origin and composition of waste water sediments, stabilization degree of their organic matter, hydration degree and structure. It was postulated that keratinophilic fungi may be utilized as microbiological indices of the transformations of organic matter of waste water sediments as well as of the degree of their deactivation from the sanitary standpoint. These fungi can be particularly useful upon utilization of the sediments for recultivation and fertilization of grounds.

Fungi↗

PubMed1989

Growth of keratinolytic and non-keratinolytic fungi on human hairs. A physiological study.

Twenty-six keratinolytic fungi (16 dermatophytes and 10 soil species) and sixteen non-keratinolytic fungi were cultivated on sterile human hair in a mineral solution. With keratinolytic fungi, the loss in total dry weight (hair + mycelium) reached 7.6 up to 24.2% after 60 days of cultivation. Peptidic (Lowry-positive) substances accumulated in the medium and pH of the medium gradually increased, often over pH 8. Excess of sulfur contained in the substrate was excreted back into the medium predominantly in the form of inorganic sulfate. Moreover, sulfite was produced that cleaved disulfide bonds of the substrate giving rise to S-sulfocysteine; soluble products of keratin degradation in the medium contained 2.1 to 6.5% of that substance. This supports the presumption that sulfitolysis of disulfide bonds is a key reaction of keratinolysis in fungi. Statistically significant correlations were observed between substrate degradation and medium alkalinization, as well as the contents of peptidic substances, sulfate, and S-sulfocysteine. The correlation was highest with sulfate content and least significant with peptidic substances. Non-keratinolytic fungi mostly grew on the hair but did not cause a gravimetrically measurable loss of the substrate, did not alkalinize the medium, and did not accumulate the above mentioned substances in amounts comparable with those of keratinolytic species.

Child↗

PubMed1989

[Quantitative study of airborne fungi at three functional sections of Chengdu city].

Airborne fungi are considered as one of the important causes of allergies throughout the world. The climatic conditions of Chengdu are suitable for the breeding of molds. We conducted monthly a quantitative investigation of the airborne fungi at three functional sections of Chengdu city from January to December, 1987. The results indicated that the concentration of fungal spores in the air was high through the year. The range of the concentrations of the airborne fungi was 870.37-7592.59 spores/m3, with two peaks in April and October. The first six dominant airborne fungi were yeast, Cladosporium, Penicillium, Aspergillus, Aureobasidium and Non-sporulating. Of Aspergillus flavus strains detected by fluorescence of agar medium under ultraviolet light 33.49% were aflatoxin-producing. The data show that the climatic and environment factors can affect the spread of airborne fungal spores in the air. The results of previous studies and present surveys are compared and the offence of airborne fungi and the significance of this survey are also discussed in this paper.

Air Microbiology↗

PubMed1986

[Morphology of fungi in the slides prepared from esophageal balloons].

1,762 cases were selected at random from 17,000 persons screened by esophageal balloon in 4 communes of Linxian County. The morphologic appearance of fungi was studied in 4 slides of each case selected. According to the shape of clumps formed by fungi and bacteria in the slides, morphologic 4 types were seen: cotton-like, camel hair-like, hair-like and tree-branch-like. In the preliminary microscopic analysis, the following species of fungi were noted: Candida, Leptothrix, Actinomyces, Alternaria, Fusarium and Penicillium. Some of the fungi in the slides may have been taken from the oral or pharyngeal cavity, which may be due to, at least in part, the poor oral hygiene in the population examined. A positive association was shown between the quantity of fungi in the slides and the esophageal epithelial dysplasia and carcinoma, but its biological significance should be studied further.

Actinomyces↗

PubMed1995

Molecular Phylogenetic classification of fungi.

Phylogenetic classification of fungi based on comparison of ribosomal RNA gene sequences is discussed with emphasis on (i) the place of fungi in all of life, (ii) the relationship of medically important fungi to other fungi including model organisms and, (iii) the integration of sexual and asexual fungi into one classification.

DNA, Ribosomal↗

PubMed1998

Antimicrobial susceptibility patterns of fungi isolated from horses with ulcerative keratomycosis.

OBJECTIVES: To evaluate in vitro susceptibility to topical antifungal medications, as measured by minimum inhibitory concentration (MIC) and 50% inhibitory concentration (IC50%), of fungal isolates from horses with ulcerative keratomycosis in Florida; to compare results with those of other studies to identify differences in susceptibility patterns among fungi isolated from horses in different geographic regions; and to note indications of fungal resistance to drugs tested in other studies. SAMPLE POPULATION: Corneal fungal cultures from client-owned horses from Florida with ulcerative keratomycosis (n = 22). PROCEDURE: Fungal cultures were plated on Emmons modified Sabouraud dextrose agar and mycobiotic agar, examined weekly for growth, and kept for a total of 30 days. In vitro MIC and IC50% of fluconazole, itraconazole, ketoconazole, miconazole, and natamycin were measured for each fungal isolate. RESULTS: Aspergillus (n = 9; 41%), Fusarium (7; 32%), Penicillium (2; 9%), Cylindrocarpon (1; 4%), Scytalidium (1; 4%), and Torulopsis (1; 4%) spp and an unidentified yeast (1; 4%) were isolated. Fungi were most susceptible to antifungal drugs in the following order: natamycin and miconazole equally, itraconazole, and ketoconazole, although no significant difference was found among drugs. Fungi were significantly less susceptible to fluconazole (P < 0.0001) than to the other 4 drugs. CONCLUSIONS: Initial antifungal therapy with topically applied natamycin, miconazole, itraconazole, or ketoconazole is recommended for ulcerative keratomycosis in horses in the subtropical environment of Florida. CLINICAL RELEVANCE: Specific antifungal treatment of horses with ulcerative keratomycosis should be based on history, results of ophthalmic examination, cytologic findings, isolation of the pathogenic fungus, and known prevalence of unique ocular fungi in specific geographic areas. In vitro antifungal susceptibility testing may be most beneficial in aiding documentation of pharmacologic susceptibility patterns of fungi in specific geographic regions.

Analysis of Variance↗

PubMed2004

The potential role of arbuscular mycorrhizal (AM) fungi in the bioprotection of plants against soil-borne pathogens in organic and/or other sustainable farming systems.

Sustainable farming systems strive to minimise the use of synthetic pesticides and to optimise the use of alternative management strategies to control soil-borne pathogens. Arbuscular mycorrhizal (AM) fungi are ubiquitous in nature and constitute an integral component of terrestrial ecosystems, forming symbiotic associations with plant root systems of over 80% of all terrestrial plant species, including many agronomically important species. AM fungi are particularly important in organic and/or sustainable farming systems that rely on biological processes rather than agrochemicals to control plant diseases. Of particular importance is the bioprotection conferred to plants against many soil-borne pathogens such as species of Aphanomyces, Cylindrocladium, Fusarium, Macrophomina, Phytophthora, Pythium, Rhizoctonia, Sclerotinium, Verticillium and Thielaviopsis and various nematodes by AM fungal colonisation of the plant root. However, the exact mechanisms by which AM fungal colonisation confers the protective effect are not completely understood, but a greater understanding of these beneficial interactions is necessary for the exploitation of AM fungi within organic and/or sustainable farming systems. In this review, we aim to discuss the potential mechanisms by which AM fungi may contribute to bioprotection against plant soil-borne pathogens. Bioprotection within AM fungal-colonised plants is the outcome of complex interactions between plants, pathogens and AM fungi. The use of molecular tools in the study of these multifaceted interactions may aid the optimisation of the bioprotective responses and their utility within sustainable farming systems.

Agriculture↗

PubMed1989

Problems in application of the terms 'blastic' and 'thallic' to modes of conidiogenesis in some onygenalean fungi.

In 1969, specialists at the Kananaskis hyphomycete workshop coined the terms 'blastic' and 'thallic' to describe two distinct modes of conidiogenesis. Since then, the original concepts have been slightly modified and redefined, and the terms have been widely adopted in taxonomic descriptions of conidial fungi. Problems arise in the application of these terms to conidial development in fungi which demonstrate morphological plasticity ranging from fragmentation of a hypha to extrusion of a portion of a hypha or cell. A number of fungi, such as anamorphs of Onygenales which includes many of the fungi pathogenic to man, demonstrate intergradations between blastic and thallic development. Because development in this group of fungi is difficult to categorize, it has led to an inconsistent treatment of taxa which share many other developmental features in common. In using these terms, it should be remembered that they represent extremes in a developmental spectrum.

Ascomycota↗

PubMed1993

Anaerobic fungi and their cellulolytic and xylanolytic enzymes.

Anaerobic fungi are the inhabitants of the digestive tract of herbivorous mammals, ruminants as well as non-ruminants. One of the major characteristics of all anaerobic fungi examined thus far, is their production and secretion of a range of polysaccharide-degrading enzymes, including cellulases, xylanases and glucoside-hydrolases. The cellulolytic enzymes of the anaerobic fungus Neocallimastix frontalis have been shown to possess a high activity. Therefore anaerobic fungi and/or their enzymes could be interesting for many biotechnological applications including saccharafication of lignocellulosic residues, production of polysaccharidehydrolysing enzymes. This review summarizes the present knowledge of anaerobic fungi with special emphasis on their cellulolytic and xylanolytic enzymes. Further, a comparison with aerobic fungi is made.

Aerobiosis↗

PubMed1996

Large-subunit rRNA sequence of the chytridiomycete Blastocladiella emersonii, and implications for the evolution of zoosporic fungi.

The 5.8S and 28S ribosomal RNA sequences of the chytridiomycete Blastocladiella emersonii were determined. These data were combined with 18S rRNA sequences in order to carry out a phylogenetic analysis based on distance matrix, parsimony, and maximum likelihood methods. The new data confirmed that chytridiomycetes are true fungi and not protists, as was already suggested on the basis of biochemical, ultrastructural, and 18S rRNA data. Within the fungal clade, B. emersonii formed the first line of divergence. The position of the fungi within the eukaryotic "crown" taxa was also reassessed, and the alveolate-stramenopile cluster appeared as their sister group. The stramenopiles also comprise a number of zoosporic fungi, which resemble chytridiomycetes in so many respects, e.g., production of motile spores, thallus morphology, and absorptive nutrition, that they have been classified together with them in the past. This suggests that the possible common ancestor of the fungi, stramenopiles, and alveolates may have been a zoosporic fungus, which would mean that zoosporic fungi are paraphyletic instead of polyphyletic as previously suggested.

Biological Evolution↗

PubMed2001

Individual and combined effects of berberine and santonin on spore germination of some fungi.

Berberine and santonin were isolated from rhizomes of Berberis aristata and unexpanded flower buds of Artemisia maritima, respectively. Efficacy of these two chemicals individually as well as of their mixtures, was tested against spore germination of some saprophytic and obligate fungi. While berberine individually was effective against most of the fungi, Helminthosporium spp. were least affected even at the highest dose (1500 ppm). Santonin was equally effective against several fungi. Mixture of both alkaloids found to be more effective than individual ones. Keeping the dose of berberine constant and santonin at two different concentrations (viz. 250 and 500 ppm) the spore germination of Helminthosporium oryzae was stimulated. Increasing concentration of santonin inhibited the spore germination of all other fungi tested, Colletotrichum capsici being affected only by 20 and 5% (at berberine concentration of 250 and 500 ppm, respectively). On the other hand, santonin being constant and berberine at different concentrations, the mixture was effective against all the fungi.

Artemisia↗

PubMed1999

Interspecific Interactions among Tropical and Subtropical Freshwater Fungi.

> Abstract Twenty-seven species of tropical and subtropical fungi isolated from freshwater were examined for evidence of interspecific interactions, which are important in determining the ecological roles of fungi. Evidence for interspecific interactions was examined by inoculating paired fungi 25 mm apart on the surface of agar plates. The antagonistic activities were different among different isolates and even between isolates of the same species, for example, Ophioceras dolichostomum isolated from different origins. Pseudohalonectria longirostrum and Kirschsteiniothelia elaterascus, which produced pigment in culture, were strongly inhibitory species. Several aquatic hyphomycetes seems to be less competitive and less likely to produce antagonistic substances. Competitive abilities were also influenced by the range of enzymes that a fungus produced. For example, Verticillium sp. and Diaporthe sp., which produced only one or two kinds of enzyme, were found to exhibit weak competitive abilities and were easily replaced. The results of competition experiments also showed that slow-extending fungi (e.g., Pseudohalonectria longirostrum and Kirschsteiniothelia elaterascus) were more competitive than early fast-extending fungi (e.g., Ophioceras dolichostomum and Nectria haematococca).http://link.springer-ny.com/link/service/journals/00248/bibs/37n4p257.html

Journal Article↗

PubMed2005

Agrobacterium-mediated transformation as a tool for functional genomics in fungi.

In the era of functional genomics, the need for tools to perform large-scale targeted and random mutagenesis is increasing. A potential tool is Agrobacterium-mediated fungal transformation. A. tumefaciens is able to transfer a part of its DNA (transferred DNA; T-DNA) to a wide variety of fungi and the number of fungi that can be transformed by Agrobacterium-mediated transformation (AMT) is still increasing. AMT has especially opened the field of molecular genetics for fungi that were difficult to transform with traditional methods or for which the traditional protocols failed to yield stable DNA integration. Because of the simplicity and efficiency of transformation via A. tumefaciens, it is relatively easy to generate a large number of stable transformants. In combination with the finding that the T-DNA integrates randomly and predominantly as a single copy, AMT is well suited to perform insertional mutagenesis in fungi. In addition, in various gene-targeting experiments, high homologous recombination frequencies were obtained, indicating that the T-DNA is also a useful substrate for targeted mutagenesis. In this review, we discuss the potential of the Agrobacterium DNA transfer system to be used as a tool for targeted and random mutagenesis in fungi.

Bacterial Proteins↗

PubMed2007

Detection of extracellular protease activity in different species and genera of ectomycorrhizal fungi.

In northern forest ecosystems, most soil nitrogen (N) is in organic form and forest trees are largely dependent on ectomycorrhizal (ECM) fungi and their degradative abilities for N uptake. The ability of ECM fungi to acquire N from organic substrates should, therefore, be a widespread trait given its ecological importance. However, little is known about the degradative abilities of most ECM fungi as they remain untested due to problems of isolation or extremely slow growth in pure culture. In this paper, we present data on extracellular protease activity of 32 species of ECM fungi, most of which have not previously been cultured. Milk powder plates and zymograms were compared for detecting protease activity in these intractable species. In total, 29/32 of the species produced extracellular protease activity, but detection was method dependent. Growth on milk powder plates detected protease activity in 28 of 32 species, while zymograms only detected proteases in Amanita muscaria, Russula chloroides, Lactarius deterrimus and Lactarius quieticolor. The study supports the hypothesis that protease excretion is a widespread physiological trait in ECM fungi and that this ability is of considerable significance for nitrogen uptake in forest ecosystems.

Ecosystem↗