990 resultados para ligninolytic fungi
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The permanent contact with cork may lead to constant exposure to fungi, raising awareness as a potential occupational hazard in the cork industry.The presence of fungi belonging to the Penicillium glabrum complex has been associated with the development of respiratory diseases such as suberosis, one of the most prevalent diseases among workers from cork industries, besides occupational asthma. Azoles are used as pesticides but also the first line therapy in the treatment of Aspergillus infections; azole-resistance as been described as to have also an environmental source and is considered an emerging public health problem.The aim of this work was to characterize fungal distribution and to evaluate the presence of azole-resistant Aspergillus isolates in nose swab samples from the cork industry workers.
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* The aim of this study was to determine the evolutionary time line for rust fungi and date key speciation events using a molecular clock. Evidence is provided that supports a contemporary view for a recent origin of rust fungi, with a common ancestor on a flowering plant. * Divergence times for > 20 genera of rust fungi were studied with Bayesian evolutionary analyses. A relaxed molecular clock was applied to ribosomal and mitochondrial genes, calibrated against estimated divergence times for the hosts of rust fungi, such as Acacia (Fabaceae), angiosperms and the cupressophytes. * Results showed that rust fungi shared a most recent common ancestor with a mean age between 113 and 115 million yr. This dates rust fungi to the Cretaceous period, which is much younger than previous estimations. Host jumps, whether taxonomically large or between host genera in the same family, most probably shaped the diversity of rust genera. Likewise, species diversified by host shifts (through coevolution) or via subsequent host jumps. This is in contrast to strict coevolution with their hosts. * Puccinia psidii was recovered in Sphaerophragmiaceae, a family distinct from Raveneliaceae, which were regarded as confamilial in previous studies.
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Soybean ( Glycine max [L.] Merr.) root rot is an important disease of soybean under continuous cropping, and root rot is widely distributed throughout the world. This disease is extremely harmful, and it is difficult to prevent and control. The study aimed to elucidate the composition of root rot pathogenic fungal communities in the continuous cropping of soybean. In this study, we employed PCRDGGE technology to analyze the communities of root rot pathogenic fungi in soybean rhizosphere soil subjected to continuous cropping during a season with a high incidence of root rot in Heilongjiang province, China, the main soybean producing area in China. The results of 13 DGGE bands were analyzed by phylogenetic revealed that the predominant root rot pathogenic fungi in rhizosphere soil in the test area were Pythium ultimum and Fusarium species. The results of cluster analysis showed that the duration of continuous cropping, the soybean variety and the plant growth stage all had significant effects on the diversity of root rot pathogenic fungi in rhizosphere soil.
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Mode of access: Internet.
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"The Board of agriculture published in 1910 a small handbook containing 25 coloured plates. This ... has been for some years out of print, and the Ministry ... has decided to republish. In the present edition the nomenclature and text-matter have been brought up-to-date. Some of the old plates have been omitted ... In their place seven new plates have been inserted."--Foreword.
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Fungi of the genus Paracoccidioides are responsible for paracoccidioidomycosis. The occurrence of drug toxicity and relapse in this disease justify the development of new antifungal agents. Compounds extracted from fungal extract have showing antifungal activity. Extracts of 78 fungi isolated from rocks of the Atacama Desert were tested in a microdilution assay against Paracoccidioides brasiliensis Pb18. Approximately 18% (5) of the extracts showed minimum inhibitory concentration (MIC) values ≤ 125.0 μg/mL. Among these, extract from the fungus UFMGCB 8030 demonstrated the best results, with an MIC of 15.6 μg/mL. This isolate was identified as Aspergillus felis (by macro and micromorphologies, and internal transcribed spacer, β-tubulin, and ribosomal polymerase II gene analyses) and was grown in five different culture media and extracted with various solvents to optimise its antifungal activity. Potato dextrose agar culture and dichloromethane extraction resulted in an MIC of 1.9 μg/mL against P. brasiliensis and did not show cytotoxicity at the concentrations tested in normal mammalian cell (Vero). This extract was subjected to bioassay-guided fractionation using analytical C18RP-high-performance liquid chromatography (HPLC) and an antifungal assay using P. brasiliensis. Analysis of the active fractions by HPLC-high resolution mass spectrometry allowed us to identify the antifungal agents present in the A. felis extracts cytochalasins. These results reveal the potential of A. felis as a producer of bioactive compounds with antifungal activity.
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Mode of access: Internet.
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2009
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"Sixth edition, revised and enlarged. Illustrated with 269 coloured figures by J.E. Sowerby."
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Nursery grown seedlings are an essential part of the forestry industry. These seedlings are grown under high nutrient conditions caused by fertilization. Though grown in a controlled environment, symbionts such as ectomycorrhizal fungi (EcMF) are often found in these conditions. To examine the effects of EcMF in these conditions, colonized Picea glauca seedlings were collected from Toumey Nursery in Watersmeet, MI. After collection, the EcMF present were morphotyped, and seedlings with different morphotypes were divided equally into two treatment types- fertilized and unfertilized. Seedlings received treatment for one growing season. After that time, seedlings were collected, ectomycorrhizas identified using morphotyping and DNA sequencing, and seedlings were analyzed for differences in leaf nutrient concentration, content, root to shoot ratio, total biomass, and EcMF community structure. DNA sequencing identified 5 unique species groups- Amphinema sp. 1, Amphinema sp. 5, Thelephora terrestris, Sphaerosporella brunnea, and Boletus variipes. In the unfertilized treatment it was found that Amphinema sp. 1 strongly negatively impacted foliar N concentration. In fertilized seedlings, Thelephora terrestris had a strong negative impact on foliar phosphorus concentration, while Amphinema sp. 1 positively impacted foliar boron, magnesium, manganese, and phosphorus concentration. In terms of content, Amphinema sp. 1 led to significantly higher content of manganese and boron in fertilized treatments, as well as elevated phosphorus in unfertilized seedlings. Amphinema sp. 5 had a significant negative effect on phosphorus content. When examining root to shoot ratio and biomass, those seedlings with more non-mycorrhizal tips had a higher root to shoot ratio. Findings from the study shed light on the interactions of the species. Amphinema sp. 5 shows very different functionality than Amphinema sp. 1. Amphinema sp. 1 appears to have the highest positive effect on seedling nutrition when in both fertilized and unfertilized environments. Amphinema sp. 5 and T. terrestris appear to behave parasitically in both fertilized and unfertilized conditions.
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This study addressed the effects of salinity and pot size on the interaction between leguminous plant hosts and arbuscular mycorrhizal fungi in four pine rockland soils using a shade house trap-plant experiment. Little is known about the belowground diversity of pine rocklands and the interactions between aboveground and belowground biota – an increased understanding of these interactions could lead to improved land management decisions, conservation and restoration efforts. Following twelve weeks of growth, plants were measured for root and shoot dry biomass and percent colonization by arbuscular mycorrhizal fungi. Overall, arbuscular mycorrhizal fungi had positive fitness effects on the four legume species (Cajanus cajan, Chamaecrista fasciculata, Tephrosia angustissima and Abrus precatorius), improving their growth rate, shoot and root biomass; pot size influenced plant-fungal interactions; and percent colonization by arbuscular mycorrhizal fungi was influenced by soil type as well as salinity.
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Filamentous fungi are a threat to the conservation of Cultural Heritage. Thus, detection and identification of viable filamentous fungi are crucial for applying adequate Safeguard measures. RNA-FISH protocols have been previously applied with this aim in Cultural Heritage samples. However, only hyphae detection was reported in the literature, even if spores and conidia are not only a potential risk to Cultural Heritage but can also be harmful for the health of visitors, curators and restorers. Thus, the aim of this work was to evaluate various permeabilizing strategies for their application in the detection of spores/conidia and hyphae of artworks’ biodeteriogenic filamentous fungi by RNA-FISH. Besides of this, the influence of cell aging on the success of the technique and on the development of fungal autofluorescence (that could hamper the RNA-FISH signal detection) were also investigated. Five common biodeteriogenic filamentous fungi species isolated from biodegradated artworks were used as biological model: Aspergillus niger, Cladosporium sp, Fusarium sp, Penicillium sp. and Exophialia sp. Fungal autofluorescence was only detected in cells harvested from Fusarium sp, and Exophialia sp. old cultures, being aging-dependent. However, it was weak enough to allow autofluorescence/RNA-FISH signals distinction. Thus, autofluorescence was not a limitation for the application of RNA-FISH for detection of the taxa investigated. All the permeabilization strategies tested allowed to detect fungal cells from young cultures by RNA-FISH. However, only the combination of paraformaldehyde with Triton X-100 allowed the detection of conidia/spores and hyphae of old filamentous fungi. All the permeabilization strategies failed in the Aspergillus niger conidia/spores staining, which are known to be particularly difficult to permeabilize. But, even in spite of this, the application of this permeabilization method increased the analytical potential of RNA FISH in Cultural Heritage biodeterioration. Whereas much work is required to validate this RNA-FISH approach for its application in real samples from Cultural Heritage it could represent an important advance for the detection, not only of hyphae but also of spores and conidia of various filamentous fungi taxa by RNA-FISH.
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The sugarcane in Brazil is passing through a management transition that is leading to the abolition of pre-harvest burning. Without burning, large amounts of sugarcane trash is generated, and there is a discussion regarding the utilization of this biomass in the industry versus keeping it in the field to improve soil quality. To study the effects of the trash removal on soil quality, we established an experimental sugarcane plantation with different levels of trash over the soil (0%, 50% and 100% of the original trash deposition) and analyzed the structure of the bacterial and fungal community as the bioindicators of impacts. The soil DNA was extracted, and the microbial community was screened by denaturing gradient gel electrophoresis in two different seasons. Our results suggest that there are no effects from the different levels of trash on the soil chemistry and soil bacterial community. However, the fungal community was significantly impacted, and after twelve months, the community presented different structures among the treatments.
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2011