Fungi isolated from Antarctic material

Summary Fungi isolated from samples of soil, penguin, skua and petrel dung and bird feathers in the Victoria Land, Antarctica, from Inexpressible Island to Cape King, were studied. All material was collected in December 1987–January 1988. Fungi occurred prevalently in bird dung and in soil, especially when mosses were present. The main species isolated were: the keratinophilic Chrysosporium verrucosum and Geomyces pannorum var. pannorum, Phoma herbarum and Thelebolus microsporus. A variety of filamentous fungi and yeasts were also encountered in soil, dung and bird feathers samples in different localities: Acremonium strictum, Cladosporium herbarum, Scolecobasidium salinum, Mortierella antarctica, Paecilomyces farinosus, Phialophora fastigiata, the thermophilic Scytalidium thermophile and Thermomyces lanuginosus, Verticillium sp., Mycelia sterilia and Cryptococcus albidus and Torulaspora delbrueckii. Most of the fungal isolates appeared to be cold-tolerant. Results from this study are discussed in conjuction with data from previous Antarctic studies in this area.     

Fungi of the Windmill Islands, continental Antarctica. Effect of temperature, pH and culture media on the growth of selected microfungi

Studies were conducted on microfungi isolated from soils in the Windmill Islands, continental Antarctica. Growth responses of Alternaria alternata, Chrysosporium pannorum, Nectria peziza, Thelebolus microsporus, Mycelia sterile and Phoma cf. herbarum to temperature, pH and culture media were investigated. Maximum growth occurred after 16 days, except in Nectria peziza and Thelebolus microsporus, where maximum growth occurred 12 days after inoculation. All isolates showed poor growth at 0°C. Maximum growth was obtained with temperatures ranging from 15 to 25°C. The optimum temperature for all fungi was 20°C. An acid medium favoured growth. Chrysosporium pannorum, Phoma cf. herbarum and Nectria peziza grew best at pH 3–4, whereas Mycelia sterile, Alternaria alternata and Thelebolus microsporus grew best at pH 5–6. The culture medium had little effect on growth, except for nutrient agar, which showed poor growth against all isolates with the exception of Thelebolus microsporus. Received: 11 September 1996 / Accepted: 13 January 1997     

Microorganisms colonizing plants and soil subjected to different degrees of human activity,including petroleum contamination,in the Vestfold hills and MacRobertson Land,Antarctica

Summary The fungal floras of plant communities and mineral soils were determined at locations both close to and away from sites of human activity. Petroleum contaminated soils and discarded wood which occur near Stations were also studied, the former for bacterial as well as fungal colonization. The fungal floras of uncontaminated natural communities comprised relatively few species, Geomyces pannorum, Phoma herbarum and Thelebolus microsporus being the most common, together with Epicoccum nigrum at Mawson. P. herbarum dominated the fungal floras of mosses at Mossell Lake but E. nigrum was also common in Mawson mossbeds. G. pannorum was widespread and colonized a range of different habitats, particularly in the Vestfold Hills. T. microsporus was also widespread particularly at sites frequented by birds and seals. Phialophora fastigiata was common around the Stations, especially Davis Station, in soils including those contaminated with oil and in wood, and is thought to have been introduced with softwood packing crates. A greater range of taxa including Mortierella, Mucor, Penicillium and Cladosporium spp. was recorded from Mawson Station than from other sites, and this was attributed to the effects of human activity. Few fungi but a range of bacteria were isolated from the petroleum contaminated soils. A high percentage of these soils contained bacteria which could utilize hydrocarbons as a sole carbon source. Some of these bacteria showed a strong degradative potential, namely Flavobacterium spp., Corynebacterium spp., Bacillus spp. and an isolate from the family Enterobacteriaceae. One isolate of Corynebacterium and the Enterobacteriaceae isolate were active hydrocarbon degraders at 1°C. Hormoconis resinae, the imperfect state of Amorphotheca resinae was only isolated from oil spill soils and then only from sites of recent spills. Geomyces pannorum and Thelebolus microsporus were less common in oil contaminated soils than in uncontaminated soils.     

Keratinophilic fungi isolated from antarctic soil

In the present study, 10 soil samples were collected aseptically from an equal number of areas of the Antarctic in the zone occupied by the 1986–1987 Italian expedition for research on keratinophilic fungi.Of particular interest was the isolation of a pathogenic fungus, Microsporum gypseum, from two sites in the base camp occupied by men and by skuas. Trichophyton terrestre was isolated from a site in which people worked and through which penguins and skuas passed.The most widespread fungal species were members of the genus Chrysosporium. Some of these species were isolated but not identified and this part of the study was still be completed.Another significant finding was the absence of fungi in one sample, while in another the widespread and abundant growth in all the seeded dishes of a single species of Chrysosporium.Other species in genera of general diffusion in many environments were also isolated : Aspergillus spp., Malbranchea sp., Mycelia sterilia spp., Paecilomyces sp., Penicillium spp. and Scopulariopsis spp.     

Enzyme Immunoassay of Herbicide Decomposition by Soil and Wood Decay Fungi

The effect of herbicide atrazine was studied on the growth and development of a number of soil and wood decay fungi: white-rot basidiomycetes (Cerrena maxima, Coriolopsis fulvocenerea, and Coriolus hirsutus), thermophilic micromycetes from self-heating grass composts (cellulolytic fungus Penicilliumsp. 13 and noncellulolytic ones Humicola lanuginosaspp. 5 and 12), and mesophilic phenol oxidase-producing micromycete Mycelia sterilia INBI 2-26. Detection of atrazine in liquid fungal cultures was performed by using the enzyme immune assay technique. Both stimulation (Humicola lanuginosa 5) and suppression (Humicola lanuginosa 12 and Penicillium sp. 13) of fungal growth with atrazine were observed on solid agar media. HyphomyceteMycelia sterilia INBI 2-26 was almost insensitive to the presence of atrazine. Neither of the thermophilic strains was capable of atrazine consumption in three-week cultivation. In contrast with that, active laccase producers Cerrena maxima, Coriolopsis fulvocenerea, and Coriolus hirsutus consumed up to 50% atrazine in 5-day cultivation in the presence of the xenobiotic and at least 80–92% in 40 days. Mycelia steriliaINBI 2-26, which also forms extracellular laccase, also consumed up to 70% atrazine in 17 days. The degree of atrazine consumption depended on the term of its addition to the fungal culture medium.     

Effects of temperature on growth rates of fungi from subantarctic Macquarie Island and Casey,Antarctica

Summary The linear growth rates of fungal isolates were measured on agar plates at temperatures ranging from 4° to 35°C. Fungi tested included the major fungal colonizers of leaves and litter of the three dominant plant species on subantarctic Macquarie Island, and major fungal species associated with plant and soil communities near Australia's Casey Station on the Antarctic Continent. All fungi grew at 4°C and were classified as psychrotrophs. Maximum growth rates were recorded at temperatures of 10° to 20°C for 13 of the 15 isolates from Macquarie Island and for all six isolates from Casey. Most of the leaf colonizing fungi from Macquarie Island had optimum growth temperatures of 15°C whereas all litter fungi from Macquarie Island and Casey fungi except Thelebolus microsporus had optimum growth temperatures of 20°C or above. Maximum growth of all species was at temperatures above those normally prevailing in their natural environments, with most species growing at 4°C at between 10% and 30% of their maximum rates. However, microclimatic effects may have resulted at times in temperatures near their growth optima. The highest growth rates at 4°C were recorded for Phoma spp. 1 and 2, Phoma exigua and Mortierella gamsii from Macquarie Island and Mortierella sp. 1 from Casey. Thelebolus microsporus and sterile sp. G from Casey also grew relatively fast at 4°C, and these species, and Phoma sp. 3 and Phoma exigua from Macquarie Island had the lowest Q-₁₀ values for the temperature range 4° to 15°C.     

Studies on the distribution of alkalophilic and alkali-tolerant soil fungi II: Fungal flora in two limestone caves in Japan

In a series of studies on the distribution of alkalophilic and alkali-tolerant fungi, soil fungi were isolated from five alkaline calcareous soil samples in two closely located limestone caves (stalactite caves) in Japan using slightly acidic and alkaline media. Some common soil fungi that can grow in alkaline conditions were obtained in high frequencies. The growth response to pH of the isolates revealed that approximately one third (30.8%) of the isolates had the optimum pH in the alkaline range. All isolates of fourAcremonium species and twoChrysosporium species grew well in alkaline conditions, of whichAcremonium sp. andChrysosporium sp. were pronounced alkalophiles. These fungi were thought to be indigenous species in this alkaline environment. The fungal flora in the Japanese alkaline soils was considerably different from the flora reported in alkaline environments in other countries.     

The occurrence of keratinophilic fungi in texas soil

Summary A total of 137 soils, 27 coming from caves and 110 from outdoor lands of Texas, were examined for the presence of keratinophilic fungi by the use of the ToKaVa hairbaiting technique. Twenty three and 69 fungal isolates, respectively, were recovered from these areas. Microsporon gypseum was the most common isolate, followed byTrichophyton mentagrophytes, andT. terrestre. M. gypseum was recovered from caves in a very high frequency (67 %), in comparison to its presence in the outdoor soils (10 %).Fifteen strains ofChrysosporium, belonging to four species, were isolated. Fourteen of these isolates were recovered from shady areas under trees. None of these had been isolated from Texas soil before.     

Fungal Decomposition of Oat Straw during Liquid and Solid-State Fermentation

White rot fungi (Coriolus hirsutus, Coriolus zonatus, and Cerrena maxima from the collection of the Komarov Botanical Institute of the Russian Academy of Sciences) and filamentous fungi (Mycelia sterilia INBI 2-26 and Trichoderma reesei6/16) were grown on oat straw–based liquid and solid media, as well as in a bench-scale reactor, either individually or as cocultures. All fungi grew well on solid agar medium supplemented with powdered oat straw as the sole carbon source. Under these conditions, the mold Trichoderma reesei fully suppressed the growth of all basidiomycetes studied; conversely,Mycelia sterilia neither affected the development of any of the cultures, nor did it show any substantial susceptibility to suppression by their presence. Pure solid cultures of basidiomycetes, as well as the coculture of Coriolus hirsutus andCerrena maxima,caused a notable bleaching of the oat straw during its consumption. When grown on the surface of oat straw–based liquid medium, the basidiomycetes consumed up to 40% of the polysaccharides without measurable lignin degradation (a concomitant process). Under these conditions, Mycelia sterilia decomposed no more than 25% of the lignin in 60 days, but this was observed only after polysaccharide exhaustion and biomass accumulation. In contrast, during solid-state straw fermentation, white rot fungi consumed up to 75% of cellulose and 55% of lignin in 83 days (C. zonarus), whereas the corresponding consumption levels for cocultures ofMycelia sterilia and Trichoderma reesei equaled 70 and 45%, respectively (total loss of dry weight ranged from 55 to 60%). Carbon dioxide–monitored solid-state fermentation of oat straw by the coculture of filamentous fungi was successfully performed in an aerated bench-scale reactor.     

Distribution and characterisation of entomopathogenic fungi from Korean soils

We investigated the occurrence of entomopathogenic fungi in 1080 soil samples representing multiple locations and conditions in Korea. Entomopathogenic fungi were isolated from soils using a selective medium containing dodine and antibiotics. Following an initial identification based on morphology, the fungal isolates were more precisely identified by the sequence of their nuclear ribosomal RNA (rRNA) internal transcribed spacer (ITS) regions. As a result, entomopathogenic fungi were found to occur in 32% (342 isolates) of the soil samples studied. The most abundant species were Beauveria spp. (125 isolates) and Metarhizium spp. (82 isolates). Entomopathogenic fungi were more often recovered from natural mountain and riparian soils than from agricultural habitats. The pathogenicity of isolated fungi was evaluated by using wax moth Galleria mellonella L. (Lepidoptera: Pyralidae) larvae. It was determined that 60% (207 isolates) of the isolates were pathogenic using this model. These entomopathogenic fungi may, therefore, have potential use against a variety of agricultural pests. This is the first study of the isolation and distribution of entomopathogenic fungi in representative sampling locations throughout Korea.     

Bird feather fungi from Svalbard Arctic

Despite feather fungi being an important component of the Arctic fungal flora, their ecological role and diversity are not fully known. In the current study, fungal cultures were isolated from feathers (barnacle goose, common eider, and glaucous gull) collected in the Ny-Ålesund region, Svalbard. Isolates were identified by ITS region sequences, which include the ITS1, ITS2, and 5.8S rRNA. The result showed culturable yeast and filamentous fungi belonging to three classes: Ascomycota (Pyrenochaetopsis pratorum, Cladosporium herbarum, Thelebolus microsporus, Aspergillus versicolor, Penicillium commune, and Venturia sp.), Basidiomycota (Mrakia blollopis and Rhodotorula mucilaginosa), and Zygomycota (Mucor flavus). Most of the fungal isolates appeared to be cold-tolerant, and about 60 % of the isolates showed keratinase activity. The reasonably low fungal diversity colonizing feathers indicates that the birds of Svalbard are casual carriers of fungi which may result in a negligible impact on their health. To the best of our knowledge, this is the first record of fungal communities present on the feathers of birds in the high Arctic.     

Seasonal study of the fungal biota of the fur of dogs

During a one year period, 944 dogs from the Municipal kennel of Barcelona were examined to detect animals with suspected dermatophytosis. Only a few animals (1.8%) presented skin lesions but none of them had dermatophytosis. A representative number of dogs without visible skin lesions (n=172), selected at random, were used to carry out a seasonal study of the mycobiota of their fur. Fifteen isolates belonging to the genera Microsporum and Trichophyton were isolated from 14 of the 172 (8.1%) dogs without lesions. The identity of these fungi was Microsporum gypseum (6/15), Trichophyton terrestre (4/15), M. canis (2/15), M. cookei (2/15) and Trichophyton ajelloi (1/15) (one strain each of M. gypseum and T. ajelloi were isolated from one dog). Species of Penicillium (% prevalence=89.5%), Alternaria (86.6%), Cladosporium (84.9%), Aspergillus (77.3%), Scopulariopsis (65.7%) and Chrysosporium (64.5%) were the most prevalent. No significant differences in the fungal biota were observed with respect to age, gender, hair length or between mixed and pure breed dogs. A large number of isolates, including species belonging to the genera Beauveria, Chrysosporium, Malbranchea and Scopulariopsis, that macroscopically and/or microscopically resemble dermatophytes and may be mistaken for them, produced a red color change in Dermatophyte Test Medium. No significant seasonal difference was detected among the isolates belonging to the the most frequently encountered genera, with the exception of Scopulariopsis (higher in summer and autumn) and Chrysosporium (higher in summer). Species from other genera, with lower occurrence also presented significant differences in their seasonal distribution. Arthrinium, Aureobasidium, Chaetomium and Phoma spp. presented maximum prevalence peaks in spring, Fusarium, Paecilomyces, Phoma and Rhizopus spp. in summer and Geotrichum and Mucor spp. in autumn. The Microsporum and Trichophyton species were more frequently isolated in summer.     

Keratinophilic fungi in the antarctic environment

Results of a study on the diffusion of keratinophilic fungi in an Antarctic environment are given. Nine soil samples collected from as many sites along the coast of Ross Sea, and six dust samples inside the Italian scientific base were examined by direct inoculation and hair baiting methods for soil samples and plate dilution method for dust samples. As regards the variety of species isolated and the counting of the numbers of colonies, plate dilution method proved to be very effective.Aspergillus spp.,Cladosporium sp., Dematiaceae,Fusarium sp.,Geomyces pannorum v.pannorum, G. pannorum v.vinaceus, Mycelia sterilia,Penicillium spp. were isolated from soil. From the dust the following moulds were isolated:Aphanoascus fulvescens, Aspergillus sp.,Beauveria sp.,Chrysosporium carmichaelii, Dematiaceae, Geomyces pannorum v.pannorum, G. pannorum v.vinaceus, Malbranchea gypsea, Mycelia sterilia, Nectria inventa, Penicillium spp.,Scopulariopsis brevicaulis, Scopulariopsis sp. andTrichophyton mentagrophytes. The presence of four colonies ofTrichophyton mentagrophytes is emphasized and correlated with the anthropization process.     

Diversity and distribution of cultured endolichenic fungi in the Ny-Ålesund Region,Svalbard (High Arctic)

Endolichenic fungi within 17 lichen species in the area near Ny-Ålesund (Svalbard, High Arctic) were studied by a culture-based method. The 247 fungal isolates were obtained from 2712 lichen thallus segments. The colonization rate of endolichenic fungi ranged from 1.6 to 26.5 %, respectively. These isolates were identified to 40 fungal taxa, including 35 Ascomycota (10 orders), 4 Basidiomycota (3 orders), and 1 unidentified fungus. Thelebolales was the most abundant order, while Sordariales were the most diverse order. The common fungal taxa shared by more than 3 lichen species were Thelebolus microsporus (93 isolates), Coniochaeta hoffmannii (7 isolates), Sarocladium kiliense (33 isolates), Coniochaeta sp. 1 (5 isolates), Coniochaeta sp. 4 (28 isolates), and Coniochaeta sp. 2 (5 isolates). Low Sorenson’s similarity coefficients were observed among different lichen species, indicating that host-related factor may shape the endolichenic fungal communities in this region. In addition, no endolichenic fungal taxa were previously found in the Antarctica and Austrian Alps, suggesting endolichenic fungal communities in this region might be also shaped by the Arctic climate. The results demonstrate the existence of specific cultured endolichenic fungal species, which may be suitable objects for further study of their possible functional roles in the lichen thalli.     

Mycological studies on the equine intestinal tract with particular reference to equine dysautonomia (grass sickness)

A wide variety of non-endophytic fungi was isolated from the stomach, colon and rectum of healthy horses, horses suffering from equine dysautonomia and horses suffering from other disorders clinically resembling dysautonomia. Of the isolates with toxin-producing potential, species of Aspergillus and Penicillium predominated. Absidia spp. occurred in virtually all horses and Rhizopus was very common, but neither is known to produce toxins. The survey did not associate any particular fungal species with equine dysautonomia.     

Consumption of Triazine Herbicide Atrazine by Laccase-positive and Laccase-negative Strains of Soil Fungus Mycelia sterilia INBI 2-26

Asporogenic fungus Mycelia sterilia INBI 2-26 isolated from tropical soils with high residual dioxin content (as a result of Agent Orange defoliant treatment during the Vietnamese–American war) and capable of atrazine decomposition was treated to obtain protoplasts. This technique resulted in isolation of laccase-positive and laccase-negative clones. Atrazine consumption by liquid surface cultures of Mycelia sterilia INBI 2-26 was monitored by using enzyme immune assay and reversed-phase HPLC. Atrazine (20 g/ml) stimulated fungal growth. The laccase-positive clone consumed up to 80% of atrazine within four weeks. However, no correlation of atrazine consumption and laccase activity in the culture medium was observed. Moreover, the laccase-negative clone was also capable of consuming at least 60–70% of atrazine within three weeks. Surprisingly, in the corresponding control set (cultivation of laccase-negative clone without atrazine) an unidentified metabolite having a retention time and UV-spectrum similar to those of atrazine was also found. It was concluded that the presence of laccase was not a crucial factor in atrazine consumption by this fungus.     

Environmental Isolates of Fungi from Aquarium Pools Housing Killer Whales (Orcinus orca)

Systemic mycoses in killer whales (Orcinus orca) are rare diseases, but have been reported. Two killer whales died by fungal infections at the Port of Nagoya Public Aquarium in Japan. In this study, the fungal flora of the pool environment at the aquarium was characterized. Alternaria spp., Aspergillus spp. (A. fumigatus, A. niger, A. versicolor), Fusarium spp. and Penicillium spp. were isolated from the air and the pool surroundings. The other isolates were identified as fungal species non-pathogenic for mammals. However, the species of fungi isolated from the environmental samples in this study were not the same as those isolated from the cases of disease in killer whales previously reported.     

Occurrence of aflatoxin B1 and ochratoxin A in Lebanese cultivated wheat

An extensive survey of filamentous fungi isolated from wheat grown and consumed in Lebanon and their capacity to produce aflatoxin B₁ (AFB₁) and ochratoxin A (OTA) was conducted to assess fungi potential for producing these toxins in wheat. From the 468 samples of wheat kernel, collected at preharvest stage from different locations during 2008 and 2009 cultivation seasons, 3,260 fungi strains were isolated with 49.4% belonging to Penicillium spp. and 31.2% belonging to Aspergillus spp. Penicillium spp. was detected on wheat samples with a high amount of P. verrucosum (37.0%). Among the different Aspergillus spp. isolated, A. niger aggregate was predominant and constituted 37.3%. whereas the isolation rate of A. flavus and A. ochraceus was 32.2 and 25.6%, respectively. The ability to produce OTA and AFB₁ by isolates belonging to Aspergillus spp. and Penicillium spp. was analyzed by high performance liquid chromatography with fluorescence detector (HPLC-FLD). It was found that 57.0% of Penicillium spp. and 80% of A. ochraceus isolates tested produced OTA, respectively, at maximum concentrations of 53 and 65 μg/g CYA. As for the aflatoxinogenic ability, 45.3% of A. flavus produced AFB₁, with maximum concentration of 40 μg/g CYA. A total of 156 wheat samples were analyzed for the levels of OTA and AFB₁ by HPLC-FLD. The results showed that 23.7% were contaminated with OTA, at a concentration higher than 3 μg/kg and 35.2% of these samples were contaminated with AFB₁ at concentration higher than 2 μg/kg. The risks originating from toxin levels in wheat produced in Lebanon should be monitored to prevent their harmful effects on public health.     

Comparative efficacy and pathogenicity of keratinophilic soil fungi against Culex quinquefasciatus larvae

Out of seven fungal species belonging to four genera isolated from pond and wallow soils using feathers of Pavo cristatus as bait, four species viz., Aspergillus flavus, Aspergillus niger, Chrysosporium pseudomerdarium and Trichophyton ajelloi were most frequent. Chrysosporium and Trichophyton spp. were more pathogenic on Culex quinquefasciatus larvae than Aspergillus and Penicillium. The bioefficacy tests conducted as per the protocol of World Health Organization and the LC₅₀ values calculated by the Probit analysis showed that 3^rd-instar C. quinquefasciatus were more susceptible to the conidia of above fungi. Highest mortality was observed in the larvae of C. quinquefasciatus when exposed to T. ajelloi. The density of fungal conidia was greatest on the ventral brush, palmate hair and anal region of the mosquito larvae after exposing for 72 hours. The potentiality of these fungi for use in the control of C. quinquefasciatus is discussed which can be exploited as a suitable biocontrol agent in the tropics.     

Fungal community associated with marine macroalgae from Antarctica

Filamentous fungi and yeasts associated with the marine algae Adenocystis utricularis, Desmarestia anceps, and Palmaria decipiens from Antarctica were studied. A total of 75 fungal isolates, represented by 27 filamentous fungi and 48 yeasts, were isolated from the three algal species and identified by morphological, physiological, and sequence analyses of the internal transcribed spacer region and D1/D2 variable domains of the large-subunit rRNA gene. The filamentous fungi and yeasts obtained were identified as belonging to the genera Geomyces, Antarctomyces, Oidiodendron, Penicillium, Phaeosphaeria, Aureobasidium, Cryptococcus, Leucosporidium, Metschnikowia, and Rhodotorula. The prevalent species were the filamentous fungus Geomyces pannorum and the yeast Metschnikowia australis. Two fungal species isolated in our study, Antarctomyces psychrotrophicus and M. australis, are endemic to Antarctica. This work is the first study of fungi associated with Antarctic marine macroalgae, and contributes to the taxonomy and ecology of the marine fungi living in polar environments. These fungal species may have an important role in the ecosystem and in organic matter recycling.