When we mention mushrooms, our minds generally turn to grilled champignons for breakfast or gnomes lurking under toadstools. But the taxonomical kingdom to which they belong, the fungi, is actually vast and highly diverse: over one hundred thousand species have been described so far, and scientists estimate that the real number could be as much as fifty times greater. Some fungi have even taken a liking to aviation fuel!
Mycological analyses of the air and food remnants in heated and non-heated rooms of the H. Arctowski Polar Station were carried out. In the material 23 fungi strains were found representing 10 species of the classes Ascomycetes, Zygomycetes and Deuteromycetes.
The purpose of the study, carried out in the years 2001–2003 was to determine which fungal species inhabited decaying grapevine cuttings during callusing and soon after planting them into pots. The plant material was collected from 5 commercial plantations and 8 cultivars, which were most frequently cultivated. From each plantation and cultivar 20 cuttings with symptoms of the growth inhibition or decay were randomly sampled during the callusing period i.e. March/April (term I) and 2–3 months after planting the cuttings into pots i.e. June/July (term II). The results showed that from affected grapevine cuttings Phomopsis viticola, Botrytis cinerea, Alternaria alternata and Fusarium spp. were isolated most frequently. Moreover, it was found that after planting young cuttings into the pots, numerous isolates of soil borne pathogenes were obtained, among others Cylindrocarpon spp., Phytophthora sp., Rhizoctonia solani, Fusarium spp.
We can hardly imagine the Earth without majestic trees and omnipresent shrubs. But not all of us realize that these plants owe their success to ubiquitous yet often unnoticeable fungi. What links these two types of organisms together is life-giving water. It is the reason why trees and fungi have been inseparable for hundreds of millions of years. How do droughts affect trees and their evolutionarily ancient symbiosis with fungi?
This paper reports on 29 species of lichenicolous fungi collected in the Hornsund region and Sørkapp Land area, Spitsbergen. New to science are Hystrix gen. nov., Slellifraga gen. nov., Dactylospora cladoniicola sp. nov., Hystrix peltigericola sp. nov., Stellifraga cladoniicola sp. nov. and Zwackhiomyces macrosporus sp. nov. A further 15 species are new to Svalbard.
This study focused on the effect of heavy metal cobalt ions (at concentrations of 1–1000 ppm) on the development and enzymatic activity of four entomopathogenic fungi: Beauveria bassiana, Beauveria brongniartii, Isaria fumosorosea and Metarhizium robertsii, commonly used in biological plant protection. It was found that each of the tested species of fungi reacted individually to contact with the Co2+ ions at their various concentrations. Depending on the variants of the experiment carried out, there were changes in the development of the mycelia (mainly growth inhibition) and their morphological features (color and structure) in comparison to the control samples. Co2+ ions had a fungistatic effect on all fungal strains, whereas a fungicidal effect was noted at concentrations of 750 ppm and 1000 ppm against M. robertsii and I. fumosorosea, respectively. In addition, there was a discrepancy in enzymatic activity between the tested fungal species developing in the medium with varying concentrations of metal salt. The inhibitory effect of Co2+ ions on lipase production was observed in I. fumosorosea. Protease production was stimulated in B. bassiana at all Co2+ concentrations, whereas in M. robertsii this effect was noted at 1 ppm. The changing dynamics of extracellular fungal hydrolases, due to the action of Co2+ ions, may translate into the role of these microorganisms in the processes of insect pathogenesis. This work suggests that severe pollution of the environment by cobalt could be a restrictive factor for the development and pathogenicity of entomopathogenic fungi and must be taken into account for their successful application in biological plant protection.
Saprotrophic filamentous microfungi were isolated by means of the soil dilution method from soil samples collected from four locations in the Bellsund region of Spitsbergen (77°33’N, 14°31’E) representing the following forms of surface micro-relief: an old stormbank, a sorted circle, a frost fissure between tundra polygons, and the central part of a tundra polygon. The fungal isolates were identified and screened for their ability to grow at low temperatures. The oligotrophy of psychrophilic and psychrotrophic strains was then determined as the ability of growth on silica gel without a C source added. Differences in some physico-chemical properties were found between the soils sampled from the four sites. A total of 89 taxa from 17 genera were isolated. Most of the isolates were species of Mortierella, Penicillium, Chrysosporium and Phialophora, and half of them were psychrophiles. Fungal communities isolated from a frost fissure between tundra polygons (site 3) and from the central part of a tundra polygon (site 4) were dominated by psychrophiles but those isolated from an old stormbank (site 1) and a sorted circle (site 2) were predominantly psychrotrophic. Oligopsychrophilic taxa accounted for 27% and oligopsychrotrophic for 20% of all the isolated taxa but only from 0.7% to 11.7% and from 1.2% to 6.3% of the total number of cfu (colony forming unit) isolated from an individual site, respectively. The results of the present study suggest that the abundance of fungi in Arctic soil is mostly affected by the content of organic matter in the A horizon and the plant cover, but other factors, such as the stage of soil development and the micro-relief of the surface, are more important for species richness of fungal communities.
The present contribution to lichen−forming and lichenicolous biota of northern− most Billefjörden (Petuniabukta area, central Spitsbergen, Svalbard) contains 40 species of lichens. Four species: Arthonia ligniariella, Candelariella lutella, Ochrolechia upsaliensis, Polyblastia pernigrata are new for the Svalbard Archipelago.
The purpose of the study was to optimize the removal of Cr(VI) by means of the Trichoderma viride strain isolated from chromium mud samples a well as the Aspergillus niger and Penicillium citrinum strains from other environments. The growth of organism and removal of chromium(VI) was carried out in water solution of various chromium(VI) contents. The research was carried out at optimal pH for each fungus i.e. Aspergillus niger 4.0, Penicillium citrinum 5.0 and Trichoderma viride 4.5. During 14 days of incubation, samples of 5 ml each were collected every day in order to determine chromium(VI) content in the solution and the efficiency of bioaccumulation of this element was then specified. Furthermore, chromium contents in filtrate and mycelium were checked to verify this type of biological activity of microorganisms. The fungi culture investigated in this study could grow at 10-125 mg/l chromium concentration which indicated that it was characterized by high tolerance to various concentrations of chromium. At 125 mg/l chromium, these organisms could accumulate successfully about 90% of chromium. High tolerance of this culture can make it a potential candidate to be a heavy metal scavenger of chromium.
This study was executed to investigate the potential of agar-agar, a nontoxic and non-degradable
gelling agent, as a promising coating agent to improve and protect banana fruit
against fungal postharvest diseases i.e., crown, finger, neck and flower end rots which are
caused by fungal isolates of Colletotrichum musae and Fusarium moniliforme. Coated-ba-nana
fruit samples with different concentrations of agar-agar suspension particularly at
2.0 g · l−1 exhibited a significant reduction in incidence and severity of postharvest diseases
compared to untreated fruit. Banana fruits dipped in agar suspension at 2.0 g · l−1 for 5, 10
and 15 min showed significant reduction in disease incidence and severity. Moreover,
application of agar suspension as a coating agent at 2.0 g · l−1 significantly decreased
weight loss (%), firmness loss (%), and soluble solid concentration of banana fruit for
15 days at 25 ± 2°C. Scanning electron microscopy observation confirmed that the fruit
coated with agar colloid at 2.0 g · l−1 had significantly fewer cracks and showed smoother
surfaces than untreated fruit. This explains the quality improvement in agar-coated fruit
compared to uncoated fruit. Overall, agar colloid, a safe coating agent, could be used to
protect banana fruit against postharvest rot diseases and extend fruit storage life during
ripening and storage.
The antifungal effect of twenty powdered spice plants and their extracts at concentrations of 2, 4, 8 and 1, 3, 6%, respectively was evaluated in relation to the radial mycelial growth of various soilborne fungi causing damping-off disease. The spice powder or extract were added to the culture medium PDA to obtain the proposed concentrations. Concentration of 8% of powdered spices and 6% of their extracts were able to cause complete growth inhibition of major tested fungi. High significant inhibitory effect on radial fungal growth was observed for different concentrations of carnation (Dianthus caryophyllus), cinnamon (Cinnamomum burmannil), garlic (Allium sativum) and thyme (Thymus vulgaris). Meanwhile, fennel (Foeniculum vulgare), marjoram (Origanum majorana) and chamomile (Matricaria hamomilla) showed a low inhibitory effect on tested fungi. Moderate inhibitory effect was observed with the other tested spices. In the greenhouse, efficacy of spice plants as powder or their extracts in addition to the fungicide Rizolex-T used as seed dressings against faba bean damping-off incidence was evaluated in pot experiment using soil artificially infested with the disease agents (Fusarium solani and Rhizoctonia solani). Spice extracts showed superior reducing effect on damping-off disease incidence at pre-emergence growth stage to that of powder treatments and Rizolex-T as well, while an opposite effect was observed at post-emergence growth stage. Carnation and cinnamon spices showed the highest protecting effect against disease incidence when applied as powder or extracts. It is interesting to note that spice plants as powder or extracts gave a similar effect to the fungicide Rhizolex-T in reducing damping-off incidence either at pre- or post-emergence stages of faba bean growth. Promising applicable technique could be suggested in the light of the results obtained. The use of spice plants as powder or extract for seed dressing might be considered as safe, cheep and easily applied method for controlling soilborne plant pathogens considering the avoidance of environmental pollution and the side effect of pesticide application.
In vitro test of antagonistic activity of culture filtrates from Trichoderma harzianum Rifai and Trichoderma pseudo-koningii Rifai strains against post-harvest pathogens of some fruits were investigated. The undiluted culture filtrates of the two Trichoderma species completely inhibited germination of conidia/spores of all the rot pathogens, but 50% dilution showed varying degree of inhibition of spore germination. T. pseudo-koningii culture filtrate had a rather moderate to strong inhibitory effect on mycelia of the pathogenic fungi. The highest per cent inhibition of 45.6% of mycelial growth was recorded for Aspergillus niger Tiegh.