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PubMed2005

The role of ubiquitous airborne fungi in chronic rhinosinusitis.

Chronic rhinosinusitis (CRS) is a confusing disease for both allergists and otorhinolaryngologists, partially due to its poorly understood pathophysiology and partially due to its limited treatment options. Several recent reports now provide evidence for a better understanding of the etiology and the relationship of CRS to airborne fungi, especially to Alternaria. First, the development of novel methods enables detection of certain fungi in mucus from the nasal and paranasal sinus cavities. Second, a non-immunoglobulin E-mediated immunologic mechanism for reactivity of CRS patients to certain common fungi has been described. Third, these fungi are surrounded by eosinophils in vivo, suggesting that they are targeted by eosinophils. Fourth, the preliminary results of studies using antifungal agents to treat patients with CRS are promising. Overall, these recent discoveries provide a logical mechanism for the pathophysiology of CRS, and they also suggest promising avenues for treatment of CRS with antifungal agents.

Air Microbiology↗
PubMed1986

The isolation of fungi from laboratory dental pumice.

Samples of used dental laboratory pumice from the two dental laboratories were cultured for the isolation of fungi. The resulting supernatant fluid from sedimentation of each pumice sample after suspension in sterile saline was serially diluted and plated onto Sabouraud agar. After incubation, fungal colonies observed were enumerated, isolated, and identified. The mean number of fungal colonies recovered from 10 pumice samples in laboratories I and II was 51.0 X 10(2) and 22.6 X 10(2), respectively. In both laboratories the predominant fungi recovered were Aspergillus niger and Fusarium sp. Other fungi recovered included Cephalosporium and Penicillium species and A. flavus. Many of these organisms have been involved in human disease. It is suggested that the presence of fungi in used dental laboratory pumice presents an unhygienic condition in the dental laboratory and may place dental laboratory technicians and denture patients at increased risk of fungal sensitization and disease.

Aspergillus niger↗
PubMed1989

Biosynthetic arginine decarboxylase in phytopathogenic fungi.

It has been reported that while bacteria and higher plants possess two different pathways for the biosynthesis of putrescine, via ornithine decarboxylase (ODC) and arginine decarboxylase (ADC); the fungi, like animals, only use the former pathway. We found that contrary to the earlier reports, two of the phytopathogenic fungi (Ceratocystis minor and Verticillium dahliae) contain significant levels of ADC activity with very little ODC. The ADC in these fungi has high pH optimum (8.4) and low Km (0.237 mM for C. minor, 0.103 mM for V. dahliae), and is strongly inhibited by alpha-difluoromethylarginine (DFMA), putrescine and spermidine, further showing that this enzyme is probably involved in the biosynthesis of polyamines and not in the catabolism of arginine as in Escherichia coli. The growth of these fungi is strongly inhibited by DFMA while alpha-difluoromethylornithine (DFMO) has little effect.

Arginine↗
PubMed1984

The impact of oil and oil-dispersant mixtures on fungi in freshwater ponds.

The impact of oil and oil-dispersant mixtures on the mycoflora of a freshwater ecosystem was assessed using man made ponds. Data indicated that the ponds were well stabilized before pond treatment. Sufficient Norman Wells crude oil to give 100 ppm was added to each treated pond. The dispersant, Corexit 9527, was initially one-fifth of the oil concentration in the oil-dispersant-treated ponds. After pond treatment, an immediate increase occurred in the number of geoaquatic fungi in the oil-treated pond whereas an increase, followed by a sharp decrease, which was in turn followed by a recovery occurred in the oil-dispersant-treated ponds. The fungal enhancement effects, which were slight, were largely short term in duration (7-83 days). No clear cut medium or long term geoaquatic fungal enhancement effects were observed. The pond treatments had no detectable effect on the vertical distribution of fungi in the ponds. No significant treatment effects were observed on the water mould levels in the treated ponds. No obvious treatment effect was observed on the percentage of viable fungi capable of growth on non-degraded or biodegraded oil as a sole carbon source. Fifteen of 39 selected pond water fungi were able to grow on non-degraded Norman Wells oil. Corexit 9527 incorporated into agar plates inhibited the radial growth of the oil utilizing fungal isolates; EC50 values were determined.

Fresh Water↗
PubMedDate not supplied

Carbon and nitrogen metabolism in ectomycorrhizal fungi and ectomycorrhizas.

The literature concerning the metabolism of carbon and nitrogen compounds in ectomycorrhizal associations of trees is reviewed. The absorption and translocation of mineral ions by the mycelia require an energy source and a reductant which are both supplied by respiratory catabolism of carbohydrates produced by the host plant. Photosynthates are also required to generate the carbon skeletons for amino acid and carbohydrate syntheses during the growth of the mycelia. Competition for photosynthates occurs between the fungal cells and the various vegetative sinks in the host tree. The nature of carbon compounds involved in these processes, their routes of metabolism, the mechanisms of control and the partitioning of metabolites between the various sites of utilization are only poorly understood. Both ascomycetous and basidiomycetous ectomycorrhizal fungi synthesize and some, if not all, accumulate mannitol, trehalose and triglycerides. The fungal strains employ the Embden--Meyerhof pathway of glucose catabolism and the key enzymes of the pentose phosphate pathway (6-phosphogluconate dehydrogenase, glucose-6-phosphate dehydrogenase, transaldolase and transketolase). Anaplerotic CO2 fixation, via pyruvate carboxylase and/or phosphoenolpyruvate carboxykinase, provides high pools of amino acids. This process could be important in the recapture and assimilation of respired CO2 in the rhizosphere. The ectomycorrhizas are thought to contain the Embden--Meyerhof pathway, the pentose phosphate pathway and the tricarboxylic acid cycle, which provide the carbon skeletons for the assimilation of ammonia into amino acids. The main route of assimilation of ammonia appears to be through the glutamine synthetase-glutamate synthase cycle in the ectomycorrhizas. Glutamate dehydrogenase plays a minor role in this process. Glutamate dehydrogenase and glutamine synthetase are present in free-living ectomycorrhizal fungi and they participate in the assimilation of ammonia and the synthesis of amino acids through the glutamate dehydrogenase/glutamine synthetase sequence. In both in vitro cultures of fungi and ectomycorrhizas, the assimilated nitrogen accumulates in glutamine. Glutamine, but also ammonia, are thought to be exported from the fungal tissues to the host cells. Studies on the metabolism of ectomycorrhizas and ectomycorrhizal fungi have focused on the metabolic pathways and compounds which accumulate in the symbiotic tissues. Studies on regulation of the overall process, and the control of enzyme activity in particular, are still fragmentary.(ABSTRACT TRUNCATED AT 400 WORDS)

Carbon↗
PubMed1988

How modern systematics relates to the rumen fungi.

The zoosporic fungi comprise a polyphyletic grouping of four classes, the Plasmodiophoromycetes, Oomycetes, Hyphochytriomycetes and Chytridiomycetes. Apart from their absorptive mode of nutrition and the presence of zoospores in some stage of their life cycle, there is little these classes have in common. The zoosporic species of rumen fungi are classified in the Class Chytridiomycetes which is a monophyletic group with extreme diversity in thallus morphology, reproduction and zoospore cytology. The rumen fungi have many characteristics in common with the Spizellomycetaceae but have been given their own family, the Neocallimasticaceae. There are arguments for reducing this family to synonymy with the Spizellomycetaceae, or elevating it to a new order, but before a rational decision can be made, more rumen fungi require detailed examination, especially their zoospore ultrastructure.

Animals↗
PubMed1991

Fossils as keys to evolution in fungi.

Both flagellated and nonflagellated fungi have an extensive fossil record, which is, however, unevenly documented and often difficult to interpret. Recent work on Silurian, Devonian and Carboniferous terrestrial assemblages has provided plausible evidence for all major groups of extant fungi in the Paleozoic. Key events in fungal macroevolution thus probably took place in the early Paleozoic or the late Precambrian, and the likelihood of finding definitive fossil evidence for them is small. The fossil record also provides evidence for morphological conservatism and early establishment of a spectrum of intimate associations between fungi and vascular plants. A model for the origin of terrestrial fungi involving two distinct lines of biotrophs in lichen-like symbioses with algae is proposed.

Biological Evolution↗
PubMed1992

Detecting morphological convergence in true fungi, using 18S rRNA gene sequence data.

For the true fungi, phylogenetic relationships inferred from 18S ribosomal DNA sequence data agree with morphology when (1) the fungi exhibit diagnostic morphological characters, (2) the sequence-based phylogenetic groups are statistically supported, and (3) the ribosomal DNA evolves at roughly the same rate in the lineages being compared. 18S ribosomal RNA gene sequence data and biochemical data provide a congruent definition of true fungi. Sequence data support the traditional fungal subdivisions Ascomycotina and Basidiomycotina. In conflict with morphology, some zygomycetes group with chytrid water molds rather than with other terrestrial fungi, possibly owing to unequal rates of nucleotide substitutions among zygomycete lineages. Within the ascomycetes, the taxonomic consequence of simple or reduced morphology has been a proliferation of mutually incongruent classification systems. Sequence data provide plausible resolution of relationships for some cases where reduced morphology has created confusion. For example, phylogenetic trees from rDNA indicate that those morphologically simple ascomycetes classified as yeasts are polyphyletic and that forcible spore discharge was lost convergently from three lineages of ascomycetes producing flask-like fruiting bodies.

DNA, Fungal↗
PubMed2006

Phospholipase A2 and phospholipase B activities in fungi.

As saprophytes or disease causing microorganisms, fungi acquire nutrients from dead organic material or living host organisms. Lipids as structural components of cell membranes and storage compartments play an important role as energy-rich food source. In recent years, it also has become clear that lipids have a wide range of bioactive properties including signal transduction and cell to cell communication. Thus, it is not surprising that fungi possess a broad range of hydrolytic enzymes that attack neutral lipids and phospholipids. Especially during infection of a mammalian host, phospholipase A(2) (PLA(2)) enzymes released by fungi could play important roles not only for nutrient acquisition and tissue invasion, but for intricate modulation of the host's immune response. Sequencing of fungal genomes has revealed a wide range of genes encoding PLA(2) activities in fungi. We are just beginning to become aware of the significance these enzymes could have for the fungal cells and their interaction with the host.

Animals↗
PubMed2006

Rate of iodine volatilization and accumulation by filamentous fungi through laboratory cultures.

Five strains of basidiomycetes (Lentinula edodes, Coprinus phlyctidosporus, Hebeloma vinosophyllum, Pleurotus ostreatus and Agaricus bisporus), one strain of ascomycete (Hormoconis resinae) and six strains of imperfect fungi (Penicillium chrysogenum, Penicillium roquefortii, Cladosporium cladosporioides, Alternaria alternata, Aspergillus niger and Aspergillus oryzae) were cultured in a liquid medium containing a radioactive iodine tracer ((125)I), and were tested for their abilities to volatilize or accumulate iodine. Of the fungal strains tested, 11 strains volatilized a considerable amount of iodine, with L. edodes showing the highest volatilization rate of 3.4%. The volatile organic iodine species emitted from imperfect fungi cultures was identified as methyl iodide (CH(3)I). In contrast, six fungal strains in 12 strains accumulated a considerable amount of iodine from the medium with concentration factors of more than 1.0. Among these, Alt. alternata and Cl. cladosporioides accumulated more than 40% of the iodine in their hyphae, and showed high concentration factors of 22 and 18, respectively. These results suggest that filamentous fungi have a potential to influence the mobility and speciation of iodine by volatilization and accumulation. Considering their great biomass in soils, filamentous fungi may contribute to the global circulation of stable iodine and also the long-lived radioiodine, (129)I (half-life: 1.6 x 10(7)years), released from nuclear facilities into the environment.

Fungi↗
PubMed2005

Acid trehalase in yeasts and filamentous fungi: localization, regulation and physiological function.

Yeasts and filamentous fungi are endowed with two different trehalose-hydrolysing activities, termed acid and neutral trehalases according to their optimal pH for enzymatic activity. A wealth of information already exists on fungal neutral trehalases, while data on localization, regulation and function of fungal acid trehalases have remained elusive. The gene encoding the latter enzyme has now been isolated from two yeast species and two filamentous fungi, and sequences encoding putative acid trehalase can be retrieved from available public sequences. Despite weak similarities between amino acids sequences, this type of trehalase potentially harbours either a transmembrane segment or a signal peptide at the N-terminal sequence, as deduced from domain prediction algorithms. This feature, together with the demonstration that acid trehalase from yeasts and filamentous fungi is localized at the cell surface, is consistent with its main role in the utilisation of exogenous trehalose as a carbon source. The growth on this disaccharide is in fact pretty effective in most fungi except in Saccharomyces cerevisiae. This yeast species actually exhibits a "Kluyver effect" on trehalose. Moreover, an oscillatory behaviour reminiscent of what is observed in aerobic glucose-limited continuous cultures at low dilution rate is also observed in batch growth on trehalose. Finally, the S. cerevisiae acid trehalase may also participate in the catabolism of endogenous trehalose by a mechanism that likely requires the export of the disaccharide, its extracellular hydrolysis, and the subsequent uptake of the glucose released. Based on these recent findings, we suggest to rename "acid" and "neutral" trehalases as "extracellular" and "cytosolic" trehalases, which is more adequate to describe their localization and function in the fungal cell.

Fungal Proteins↗
PubMed2006

Survey and significance of filamentous fungi from tap water.

Fungi in drinking water are involved in the production of tastes and odours in water. Health problems are possible, originating from mycotoxins, animal pathogens and allergies. This report concerns the surveillance of mesophilic fungi in tap water and assessment of their potential for causing problems. The methods for the determination of the filamentous fungi (ff) were filtering, swabbing and baiting. Tap water, half-strength corn meal, neopeptone-glucose rose Bengal aureomycin (NGRBA) and oomycete selective agars for the enumeration of colony forming units (cfu) were used. Samples were taken consecutively over 16 months. Filtration and NGRBA gave the highest ff counts. A total of 340 taxa were isolated. There appeared to be a negative correlation between bacterial and yeast (b/y) and ff counts. Highest counts were found in winter months for ff and in the warmer months for b/y. Penicillium (40.6%) and Acremonium (38.8%) were the most frequently isolated ff. There was a difference in the pattern of isolation of the key taxa with season: penicillia predominated in early summer and Acremonium in winter. P. expansum was isolated in high numbers in May 2004. This species is associated with the production of the mycotoxin patulin and the odour secondary metabolite geosmin. P. brevicompactum was detected throughout the sampling period and is known to produce the immunosuppressive drug mycophenolic acid. Acremonium is associated with ocentol production which is responsible for bad tastes and flavours. The remaining taxa were Phialophora sp. (4.1%), Cladosporium sp. (3.5%), Rhizopus stolonifer (2.9%), Chaetomium sp. (0.6%), Alternaria sp. (0.3%), Aspergillus sp. (0.3%), mycelia sterilia (2.6%) and unidentified (6.2%). It is emphasised that few Aspergillus and no Fusarium strains were isolated. Rhizopus stolonifer was obtained. However, none of the fungi isolated at mesophilic temperature used could be described as being involved with pathogenicity per se.

Colony Count, Microbial↗
PubMed2005

Real-time detection of common microbial volatile organic compounds from medically important fungi by Selected Ion Flow Tube-Mass Spectrometry (SIFT-MS).

We describe a new method, Selected Ion Flow Tube-Mass Spectrometry (SIFT-MS) for the rapid and sensitive real-time detection and quantification of volatile organic compounds from medically important fungi, grown on a range of laboratory media. SIFT-MS utilises the chemical ionisation reactions of mass-selected ions to characterise volatile organic compounds (VOCs) that are produced as metabolites from fungi. This technique has the distinct advantage over others in that it readily detects low molecular weight, reactive volatiles, and allows for real-time, quantitative monitoring. The fungi examined in this study were Aspergillus flavus, Aspergillus fumigatus, Candida albicans, Mucor racemosus, Fusarium solani, and Cryptococcus neoformans grown on or in malt extract agar, Columbia agar, Sabouraud's dextrose agar, blood agar, and brain-heart infusion broth. Common metabolites (ethanol, methanol, acetone, acetaldehyde, methanethiol, and crotonaldehyde) were detected and quantified. We found the fingerprint of volatiles, in terms of presence and quantity of volatiles to be strongly dependent on the culture medium, both in terms of variety and quantity of volatiles produced, but may form the basis for species specific identification of medically important fungi.

Culture Media↗
PubMed2006

Detection of active soil fungi by RT-PCR amplification of precursor rRNA molecules.

Microbial ecologists have used direct RT-PCR amplification of 16S rRNA molecules for the detection of active species of bacteria and archaea, and 18S rRNA molecules for the detection of active fungi. The drawback to this approach for fungi is that 18S rRNA sequences often do not provide sufficient taxonomic resolution to allow identification of taxa in mixed communities to genus or species level. Internal transcribed spacer (ITS) sequences are known to be more taxonomically informative than 18S rRNA sequences and are the common target in DNA based studies but are thought to be absent from RNA pools as they are cleaved after transcription of the large rRNA precursor molecule to leave the mature rRNA's for ribosome synthesis. Here we show, however, that fungal ITS regions can be detected in RNA pools by RT-PCR amplification of fungal precursor rRNA molecules. This suggests that precursor rRNA molecules reside in the cells of active fungi for sufficient time to allow RT-PCR amplification of ITS regions prior to their removal by post-transcriptional cleavage. The RT-PCR conditions for this approach were initially optimised using a range of fungi grown in pure culture prior to applying the approach to complex fungal communities in two contrasting soil types.

Cloning, Molecular↗
PubMed2006

Characterization of fungi from hypersaline environments of solar salterns using morphological and molecular techniques.

The Cabo Rojo Solar Salterns located on the southwest coast of Puerto Rico are composed of two main ecosystems (i.e., salt ponds and microbial mats). Even though these locations are characterized by high solar radiation (mean light intensity of 39 mol photons m-2d-1) they harbour a diverse microscopic life. We used morphological and molecular techniques to identify a series of halotolerant fungi. A total of 183 isolates and 36 species were cultured in this study. From the water from the salt ponds, 86 isolates of 26 species were cultured. The halotolerant fungi isolated from water were: Cladosporium cladosporioides, nine Aspergillus sp., five Penicillium sp. and the black yeast Hortaea werneckii. A distinctive isolate with a blue mycelium was cultured from the salt ponds, representing a new species of Periconia based on morphology and rDNA analysis. Forty-four isolates from eight species were cultured from the sediments around the salt ponds. Most of the sediment isolates formed only sterile mycelium, while several were Chaetomium globosum. A total of 53 isolates from 16 species were isolated from the three layers of the microbial mats, of which Aspergillus niger was the most frequent isolate. Phospholipid fatty acid profiles generated from the different layers of the microbial mats indicated that the uppermost layers of the mats contained fungal biomarker, 18:2w6. This fatty acid decreased with depth, the highest concentration was observed in the green upper layer and it disappeared in the black bottom anoxic layer. This correlates with the isolation of fungi using the serial dilution technique. This is the first study that documents the presence of fungi in microbial mats.

DNA, Ribosomal Spacer↗
PubMed2006

Prescribed burning in a Eucalyptus woodland suppresses fruiting of hypogeous fungi, an important food source for mammals.

Fruit bodies of hypogeous fungi are an important food source for many small mammals and are consumed by larger mammals as well. A controversial hypothesis that prescribed burning increases fruiting of certain hypogeous fungi based on observations in Tasmania was tested in the Australian Capital Territory to determine if it applied in a quite different habitat. Ten pairs of plots, burnt and nonburnt, were established at each of two sites prescribe-burnt in May 1999. When sampled in early July, after autumn rains had initiated the fungal fruiting season, species richness and numbers of fruit bodies on the burnt plots were extremely low: most plots produced none at all. Both species richness and fruit body numbers were simultaneously high on nonburnt plots. One of the sites was resampled a year after the initial sampling. At that time species richness and fruit body abundance were still significantly less on burnt plots than on nonburnt, but a strong trend towards fungal recovery on the burnt plots was evident. This was particularly so when numbers of fruit bodies of one species, the hypogeous agaric Dermocybe globuliformis, were removed from the analysis. This species strongly dominated the nonburnt plots but was absent from burnt plots in both years. The trend towards recovery of fruit body abundance in the burnt plots one year after the burn was much more pronounced with exclusion of the Dermocybe data. The Tasmanian-based hypothesis was based mostly on the fruiting of two fire-adapted species in the Mesophelliaceae. Neither species occurred on our plots. Accordingly, the results and conclusions of the Tasmanian study cannot be extrapolated to other habitats without extensive additional study. Implications for management of habitat for fungi and the animals that rely on the fungi as a food source are discussed.

Animals↗
PubMed2006

Polyphenol oxidases in plants and fungi: going places? A review.

The more recent reports on polyphenol oxidase in plants and fungi are reviewed. The main aspects considered are the structure, distribution, location and properties of polyphenol oxidase (PPO) as well as newly discovered inhibitors of the enzyme. Particular stress is given to the possible function of the enzyme. The cloning and characterization of a large number of PPOs is surveyed. Although the active site of the enzyme is conserved, the amino acid sequence shows very considerable variability among species. Most plants and fungi PPO have multiple forms of PPO. Expression of the genes coding for the enzyme is tissue specific and also developmentally controlled. Many inhibitors of PPO have been described, which belong to very diverse chemical structures; however, their usefulness for controlling PPO activity remains in doubt. The function of PPO still remains enigmatic. In plants the positive correlation between levels of PPO and the resistance to pathogens and herbivores is frequently observed, but convincing proof of a causal relationship, in most cases, still has not been published. Evidence for the induction of PPO in plants, particularly under conditions of stress and pathogen attack is considered, including the role of jasmonate in the induction process. A clear role of PPO in a least two biosynthetic processes has been clearly demonstrated. In both cases a very high degree of substrate specificity has been found. In fungi, the function of PPO is probably different from that in plants, but there is some evidence indicating that here too PPO has a role in defense against pathogens. PPO also may be a pathogenic factor during the attack of fungi on other organisms. Although many details about structure and probably function of PPO have been revealed in the period reviewed, some of the basic questions raised over the years remain to be answered.

Catechol Oxidase↗
PubMed2006

Inflammatory potency of dust from the indoor environment and correlation to content of NAGase and fungi.

The aim of this study was to analyse the contribution of microbial factors to the inflammatory potency of dust (PD). Floor dust was sampled three times from 12 rooms in two schools. The potency of floor dust was measured as interleukin-8 secretion from the lung epithelial cell line A549 after exposure to dust. Measurements of endotoxin, NAGase activity and cultivable fungi in the dust were made. For endotoxin a difference was found between sampling days and for NAGase a difference was found between the schools. The carpeted staff rooms of the two schools had a significantly higher amount of dust/m(2) and endotoxin/m(2), and the PD/m(2) and NAGase activity/m(2) were also higher than in the classrooms with smooth flooring. The PD/m(2) correlated with all fungal parameters except total cultivable fungi. NAGase/m(2) correlated with PD, endotoxin and cultivable Cladosporium sp. per area, and was nearly significantly correlated to total cultivable fungi and Penicillium spp. Therefore; microbiological activity especially from fungi may contribute to the inflammatory potency of floor dust. Carpet flooring may act as a "sink" for microorganisms resulting in a higher inflammatory potency of floor dust, which may reflect building-related symptoms in occupants.

Acetylglucosaminidase↗