Mycological survey of selected health foods.

A survey was conducted to compare the total viable fungal content and the number of different mold species encountered in 10 types of health foods labeled organically grown and in the same foods without such a label. The foods were wheat flour, corn meal, brown rice, figs, split peas, pinto beans, soybeans, walnuts, pecans, and peanuts. Results showed no consistent difference in either the total viable fungal content or the number of different mold species encountered between the labeled and unlabeled foods. Two genera of yeasts (Rhodotorula and Saccharomyces) and 22 gener of molds, including more than 65 species, were encountered. The mold flora was dominated by Aspergillus glaucus, Aspergillus niger, Aspergillus flavus, Aspergillus candidus, Penicillium cyclopium, and Penicillium viridicatum. Isolates of the genera Alternaria, Cladosporium, Fusarium, and Helminthosporium also occurred in certain foods. At least 10 toxicogenic species of Aspergillus and Penicillium were encountered. A total of 87 cultures of these species, all isolated from health foods, were screened for laboratory production of their respective toxins. Toxin production potential of these 87 cultures did not differ from that of cultures of the same species isolated from conventional foods.     

Diversity and significance of mold species in Norwegian drinking water

In order to determine the occurrence, distribution, and significance of mold species in groundwater- and surface water-derived drinking water in Norway, molds isolated from 273 water samples were identified. Samples of raw water, treated water, and water from private homes and hospital installations were analyzed by incubation of 100-ml membrane-filtered samples on dichloran-18% glycerol agar. The total count (number of CFU per 100 ml) of fungal species and the species diversity within each sample were determined. The identification of mold species was based on morphological and molecular methods. In total, 94 mold species belonging to 30 genera were identified. The mycobiota was dominated by species of Penicillium, Trichoderma, and Aspergillus, with some of them occurring throughout the drinking water system. Several of the same species as isolated from water may have the potential to cause allergic reactions or disease in humans. Other species are common contaminants of food and beverages, and some may cause unwanted changes in the taste or smell of water. The present results indicate that the mycobiota of water should be considered when the microbiological safety and quality of drinking water are assessed. In fact, molds in drinking water should possibly be included in the Norwegian water supply and drinking water regulations.     

Fungi and ochratoxin A detected in healthy grapes for wine production

AIMS: The mycoflora of healthy grapes (i.e. without visible symptoms of rot) for wine production in Portuguese wine-making regions was assessed and its potential for ochratoxin A (OTA) production evaluated. The OTA content of grapes was also determined. METHODS AND RESULTS: A total of 386 fungal strains were isolated by plating methods. The most frequent genera found in grapes were non-ochratoxigenic species: Cladosporium (28%), Penicillium (24%), Botrytis (13%) and Aspergillus (9%). Two OTA-producing strains were isolated, belonging to the species Aspergillus carbonarius and Aspergillus ochraceus. OTA was detected in three of four grape samples, up to 116 ng l(-1). CONCLUSIONS: OTA is being produced in healthy berries by Aspergillus species, namely A. carbonarius, at levels below the maximum recommended limit of 2,000 ng l(-1) in wine. SIGNIFICANCE AND IMPACT OF THE STUDY: The OTA concentration detected in healthy Portuguese grapes does not represent a risk to wine regarding the legal limit established.     

Osmophilous fungi in the salt marshes of Kuwait.

During an investigation of the mycoflora inhabiting saline soils in Kuwait, special attention was focused on osmophilous fungi. A total of 101 species belonging to 46 genera were encountered from 40 soil samples collected from salt marshes using Czapek's agar supplemented with 40% sucrose. Soil samples were collected from different habitats at different distances from the water edge. Soils near to the water edge were poor in their fungal content, while those taken from areas covered by Juncus arabicus contained highest fungal populations. The recorded genera were classified as follows: 7 were of high frequency of occurrence, 8 moderate, 17 low, and 13 were rare. The order of dominance was Aspergillus, Alternaria, Penicillium, Cephalosporium, Fusarium, Stachybotrys, and Drechslera. Comparison between our results and those in other studies showed that there is no fungal flora characteristic of saline soils.     

Isolation and identification of indoor airborne fungal contaminants of food production facilities and warehouses in Bursa, Turkey

In this study, we aimed at the isolation and identification of indoor airborne fungal contaminants of 16 different food production facilities and warehouses located in Bursa province (Turkey). Numbers and kinds of microfungi were investigated by exposing a Petri dish of malt extract agar medium for 15 minutes and then counting the number of colonies which develop. Sampling procedure for microfungi was performed 8 times at an interval of 45 days between Dec. 1st 1995--Oct. 15th 1996. A total of 3152 colonies was counted on 864 petri plates in a one year period. As a result, 63 mould species and 4 varieties belonging to 20 genera were isolated by means of pure culture methods. Of these, 7 species and 1 variety belonging to Aspergillus and Penicillium genera are new records for Turkey.     

Fungal Air Spora at Ibadan, Nigeria

The fungal air spora at Ibadan, Nigeria, was investigated by using Casella Slit Samplers. Three sites, incorporating three locations at each site, were selected for the exposure of replicate plates during sampling. To provide data on a wide range of saprophytic and pathogenic fungal spores, isolations were made on Sabouraud dextrose agar and malt agar plates incubated at 26 and 37 C. Altogether over 60,000 fungal colonies were isolated and counted during the 12-month sampling period. The prevalent fungal genera recorded were: Cladosporum, Curvularia, Fusarium, Aspergillus, Penicillium, Pithomyces, Aureobasidium, Geotrichum, Phoma, Nigrospora, Epicoccum, and Neurospora. The wet and dry seasons (indicated by the temperature, relative humidity, and rainfall data) caused seasonal periodicity in colony numbers. The influence of culture media on the isolated colonies was not significant when the total number of isolated colonies were considered on a monthly basis, but in reviewing a few of the fungal genera there were marked differences between the two media, especially with Pithomyces. Attempts were made to identify some of the isolated colonies by species, e.g., Aspergillus carneus, Aspergillus flavus, Aspergillus fumigatus, Curvularia geniculata, Fusarium oxysporum, Penicillium herquei, Pithomyces chartaum, Rhizopus arrhizus, and Syncephalastrum racemosum. Such identifications provide a basis for further studies on the role of these fungal species in the frontier problem of contamination and biodegradation of drugs and pharmaceuticals, allergies and other problems in the local environment.     

Fungal fragments as indoor air biocontaminants

The aerosolization process of fungal propagules of three species (Aspergillus versicolor, Penicillium melinii, and Cladosporium cladosporioides) was studied by using a newly designed and constructed aerosolization chamber. We discovered that fungal fragments are aerosolized simultaneously with spores from contaminated agar and ceiling tile surfaces. Concentration measurements with an optical particle counter showed that the fragments are released in higher numbers (up to 320 times) than the spores. The release of fungal propagules varied depending on the fungal species, the air velocity above the contaminated surface, and the texture and vibration of the contaminated material. In contrast to spores, the release of fragments from smooth surfaces was not affected by air velocity, indicating a different release mechanism. Correlation analysis showed that the number of released fragments cannot be predicted on the basis of the number of spores. Enzyme-linked immunosorbent assays with monoclonal antibodies produced against Aspergillus and Penicillium fungal species showed that fragments and spores share common antigens, which not only confirmed the fungal origin of the fragments but also established their potential biological relevance. The considerable immunological reactivity, the high number, and the small particle size of the fungal fragments may contribute to human health effects that have been detected in buildings with mold problems but had no scientific explanation until now. This study suggests that future fungal spore investigations in buildings with mold problems should include the quantitation of fungal fragments.     

湛江红树林滩涂可培养真菌种群多样性分析

【目的】明确湛江地区红树林滩涂海洋真菌的种类及其分布,为海洋真菌的开发利用研究奠定基础。【方法】运用稀释平板法从湛江市高桥及特呈岛红树林滩涂不同的潮位带(低、中、高)和不同树种(白骨壤、桐花树、木榄、红海榄)采集淤泥样品550份,采用真菌形态学和ITS序列分析技术进行多样性研究【。结果】分离获得海洋真菌274株,共鉴定出19属39种真菌,以曲霉属Aspergillus、青霉属Penicillium和木霉属Trichoderma真菌分离频率高,为湛江红树林滩涂优势真菌种类,尤其在中潮位带真菌种类最多。此外,分离获得真菌Talaromyces helicus,为中国新记录种。【结论】湛江红树林滩涂海洋真菌的种类十分丰富,具有潜在的开发和利用前景。     

Studies on soil fungi III. Seasonal variation and distribution of microfungi in some soils of Andhra Pradesh (India)

The seasonal variation and distribution of microfungi in four soil types collected from two districts of Andhra Pradesh (India) were studied.Besides soil type and surface vegetation, it appears from the present study that soil moisture, organic matter, potassium, calcium, iron and phosphorus contents also may affect the fungal numbers favourably, while chlorides, total soluble salts, total nitrogen and manganese contents may have an adverse effect.Even alkaline soils harbour greater numbers of fungi, but small fluctuations in the pH seem to influence the fungal numbers in soils inversely.A total of 101 species representing 43 genera were isolated. These included 18 Phycomycetes, 5 Ascomycetes, 72 Fungi Imperfecti, 5 Mycelia Sterilia and a single Myxomycete. The order of occurrence of the chief genera of fungi isolated wasAspergillus, Penicillium, Fusarium, Pythium, Curvularia, Phoma, Cunninghamella, Rhizopus, Alternaria andTrichoderma.A large number of genera and species were found common to the forest, maize field, garden and uncultivated soils; and the fungal flora was also not very much different from those recorded from various parts of the world.     

Ochratoxin production by the Aspergillus ochraceus group and Aspergillus alliaceus

Ochratoxin A is a toxic and carcinogenic fungal secondary metabolite; its presence in foods is increasingly regulated. Various fungi are known to produce ochratoxins, but it is not known which species produce ochratoxins consistently and which species cause ochratoxin contamination of various crops. We isolated fungi in the Aspergillus ochraceus group (section Circumdati) and Aspergillus alliaceus from tree nut orchards, nuts, and figs in California. A total of 72 isolates were grown in potato dextrose broth and yeast extract-sucrose broth for 10 days at 30 degrees C and tested for production of ochratoxin A in vitro by high-pressure liquid chromatography. Among isolates from California figs, tree nuts, and orchards, A. ochraceus and Aspergillus melleus were the most common species. No field isolates of A. ochraceus or A. melleus produced ochratoxin A above the level of detection (0.01 microg/ml). All A. alliaceus isolates produced ochratoxin A, up to 30 microg/ml. We examined 50,000 figs for fungal infections and measured ochratoxin content in figs with visible fungal colonies. Pooled figs infected with A. alliaceus contained ochratoxin A, figs infected with the A. ochraceus group had little or none, and figs infected with Penicillium had none. These results suggest that the little-known species A. alliaceus is an important ochratoxin-producing fungus in California and that it may be responsible for the ochratoxin contamination occasionally observed in figs.     

Monitoring of microbial degraders in manned space stations

Samples of microorganisms from the surface of constructions of Mir Space Station (Mir SS) were taken and examined after 13 years of operation. The following microorganisms were isolated and identified: 12 fungal species belonging to the genera Penicillium, Aspergillus, Cladosporium, and Aureobasidium; 3 yeast species belonging to the genera Debaryomyces, Candida, and Rhodotorula; and 4 bacterial species belonging to the genera Bacillus, Myxococcus, and Rhodococcus. The predominant species in all samples was Penicillium chrisogenum. It was shown that the fungi isolated could damage polymers and induce corrosion of aluminum-magnesium alloys. We commenced a study of microbial degraders on constructions of the Russian section of the International Space Station (RS ISS). Twenty-six species of fungi, bacteria, yeasts, and actinomycetes, known as active biodegraders, were identified in three sample sets taken at intervals. We founded a collection of microorganisms surviving throughout space flights. This collection can be used to test spacecraft production materials, in order to determine their resistance to biodegradation.     

Fungal endophytes in green coffee seeds

Green coffee seeds from Colombia, Guatemala, India, Kenya, Papua New Guinea, Puerto Rico and Vietnam were sampled for the presence of fungal endophytes. Stions of surface sterilized seeds were plated on yeast malt agar, and fungal growth was isolated for subsequent DNA extraction and sequencing. Several fungal genera were isolated, including Acremonium, Aspergillus, Eurotium, Fusarium, Gibberella, Penicillium, Pseudozyma and an undescribed clavicipitaceous species. The biological activities that these fungi might be playing in coffee seeds remain unknown, but in other plants some of the genera isolated have been reported to protect against plant pathogens.     

Fungal flora of the digestive tract of Panstrongylus megistus (Reduviidae) used for experimental xenodiagnosis of Trypanosoma (Schizotripanum) cruzi Chagas, 1909

A survey of the fungi isolated from the digestive tract of Panstrongylus megistus (insects vectors from Chagas' disease) used on xenodiagnosis was carried out. Two hundred and fourteen fungal strains were isolated from 180 nymphs. Aspergillus and Penicillium were the most predominant genera and some of their species were new records concerning insects. A great reduction in the fungal population was observed in the material that was positive for Trypanosoma cruzi.     

咖啡种子中的内生真菌

Green coffee seeds from Colombia, Guatemala, India, Kenya, Papua New Guinea, Puerto Rico and Vietnam were sampled for the presence of fungal endophytes. Stions of surface sterilized seeds were plated on yeast malt agar, and fungal growth was isolated for subsequent DNA extraction and sequencing. Several fungal genera were isolated, including Acremonium, Aspergillus, Eurotium, Fusarium, Gibberella, Penicillium, Pseudozyma and an undescribed clavicipitaceous species. The biological activities that these fungi might be playing in coffee seeds remain unknown, but in other plants some of the genera isolated have been reported to protect against plant pathogens.     

咖啡种子中的内生真菌

Green coffee seeds from Colombia, Guatemala, India, Kenya, Papua New Guinea, Puerto Rico and Vietnam were sampled for the presence of fungal endophytes. Stions of surface sterilized seeds were plated on yeast malt agar, and fungal growth was isolated for subsequent DNA extraction and sequencing. Several fungal genera were isolated, including Acremonium, Aspergillus, Eurotium, Fusarium, Gibberella, Penicillium, Pseudozyma and an undescribed clavicipitaceous species. The biological activities that these fungi might be playing in coffee seeds remain unknown, but in other plants some of the genera isolated have been reported to protect against plant pathogens.     

Alternaria alternata prevalence in cereal grains and soybean seeds from Entre Ríos, Argentina

A mycological survey was carried out at Entre Ríos province, Argentina, on sorghum grain, maize, rice, soybean seeds and on freshly harvested and stored wheat. The isolation frequencies and relative densities of species belonging to genera Alternaria, Aspergillus, Fusarium, Penicillium and other fungi were calculated. Alternaria alternata was the major fungal species isolated from sorghum, rice, soybean seeds and on freshly harvested wheat, and a low incidence of Fusarium species was observed on the same substrates. In maize the major fungal species isolated was Fusarium verticillioides. The high incidence levels of A. alternata observed,suggest that it may be necessary to determine, among other mycotoxins, if Alternaria toxins occur in these commodities.     

Fungal flora of the digestive tract of 5 species of triatomines vectors of Trypanosoma cruzi,Chagas 1909

A study of the mycobiota in the digestive tract of 5 important species of triatomines, Triatoma brasiliensis, T. infestans, T. sordida, T. pseudomaculata and T. vitticeps, was made. The digestive tracts of 164 adults and 535 nymphs of those triatomines were studied and 393 fungal strains were isolated.The genera with the greatest number of species were Penicillium (19 species), Aspergillus (17 species) and Acremonium (5 species) and the most frequent species, in decreasing order, were Penicillium corylophilum, Aspergillus niger, Penicillium fellutanum, Cladosporium herbarum, Penicillium waksmanii, Aspergillus awamori and Paecilomyces variotii. Among the isolated fungi, we found species that are recognized as entomopathogenic and pathogenic for humans and animals.This revised version was published online in October 2005 with corrections to the Cover Date.     

Mycotoxin-Producing Potential of Mold Flora of Dried Beans

To evaluate the potential for mycotoxin production by molds in dried beans, the mold flora of 114 samples was determined both before and after surface disinfection of the beans with 5% NaOCl. Surface disinfection substantially reduced mold incidence, indicating that contamination was mainly on the surface. The flora, both before and after disinfection, was dominated by species of the Aspergillus glaucus group, the toxicogenic species A ochracues, Penicillium cyclopium, and P. viridicatum, and species of Alternaria, Cladosporium, and Fusarium. The toxicogenic species Aspergillus flavis, A. versicolor, Penicillium Citrinum, P. expansum, P. islandicum, and P. urticae were encountered less frequently. Of 209 species of Aspergillus and Penicillium screened for mycotoxin production on sterile rice substrate, 114 produced one or more of the following mycotoxins: A. flavus, aflatoxins; A. ochraceus, ochratoxins; A. nidulans, A. unguis, and A. versicolor, sterigmatocystin; P. cyclopium, penicillic acid; P. citrinum and P. viridicatum, citrinin; P. urticae, patulin and griseofulvin. Sterigmatocystin production by A. unguis is reported for the first time.     

Seed-borne fungi of five cruciferous vegetables and relative efficacy of aqueous seed extracts against some associated fungi

A total of 121 seed samples of cabbage, cauliflower, cress, radish and turnip collected from five localities in Upper Egypt were assayed for their fungal flora. The highest count of fungi was recorded on cabbage seeds (75%), whereas the lowest count was observed on turnip seeds (33%). Thirty-five fungal species and two varieties belonging to 16 genera were identified. The broadest number of species (22 species + 1 variety) were isolated from cress seeds. However, only five species,viz. Aspergillus flavus, A. niger, Penicillium chrysogenum, P. funiculosum andRhizopus stolonifer, were found to be associated with seeds of the five plants. The relative efficacy of aqueous seed extracts against these five fungal species was tested. The antifungal drug Trosyd (tioconazole) was taken as a standard inhibitor. The aqueous extract of cabbage seeds inhibited three fungal species, cress extract two and cauliflower and turnip one species; radish seed extract was ineffective.     

Analysis of fungal flora in indoor dust by ribosomal DNA sequence analysis, quantitative PCR, and culture

In recent years increasing attention has been given to the potential health effects of fungal exposure in indoor environments. We used large-scale sequencing of the fungal internal transcribed spacer region (ITS) of nuclear ribosomal DNA to describe the mycoflora of two office buildings over the four seasons. DNA sequencing was complemented by cultivation, ergosterol determination, and quantitative PCR analyses. Sequences of 1,339 clones were clustered into 394 nonredundant fungal operational taxonomical units containing sequences from 18 fungal subclasses. The observed flora differed markedly from that recovered by cultivation, the major differences being the near absence of several typical indoor mold genera such as Penicillium and Aspergillus spp. and a high prevalence of basidiomycetes in clone libraries. A total of 55% of the total diversity constituted of unidentifiable ITS sequences, some of which may represent novel fungal species. Dominant species were Cladosporium cladosporioides and C. herbarum, Cryptococcus victoriae, Leptosphaerulina americana and L. chartarum, Aureobasidium pullulans, Thekopsora areolata, Phaeococcomyces nigricans, Macrophoma sp., and several Malassezia species. Seasonal differences were observed for community composition, with ascomycetous molds and basidiomycetous yeasts predominating in the winter and spring and Agaricomycetidae basidiomycetes predominating in the fall. The comparison of methods suggested that the cloning, cultivation, and quantitative PCR methods complemented each other, generating a more comprehensive picture of fungal flora than any of the methods would give alone. The current restrictions of the methods are discussed.