35 research outputs found

    Proteomic Analysis of Fusarium solani Isolated from the Asian Longhorned Beetle, Anoplophora glabripennis

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    Wood is a highly intractable food source, yet many insects successfully colonize and thrive in this challenging niche. Overcoming the lignin barrier of wood is a key challenge in nutrient acquisition, but full depolymerization of intact lignin polymers has only been conclusively demonstrated in fungi and is not known to occur by enzymes produced by insects or bacteria. Previous research validated that lignocellulose and hemicellulose degradation occur within the gut of the wood boring insect, Anoplophora glabripennis (Asian longhorned beetle), and that a fungal species, Fusarium solani (ATCC MYA 4552), is consistently associated with the larval stage. While the nature of this relationship is unresolved, we sought to assess this fungal isolate's ability to degrade lignocellulose and cell wall polysaccharides and to extract nutrients from woody tissue. This gut-derived fungal isolate was inoculated onto a wood-based substrate and shotgun proteomics using Multidimensional Protein Identification Technology (MudPIT) was employed to identify 400 expressed proteins. Through this approach, we detected proteins responsible for plant cell wall polysaccharide degradation, including proteins belonging to 28 glycosyl hydrolase families and several cutinases, esterases, lipases, pectate lyases, and polysaccharide deacetylases. Proteinases with broad substrate specificities and ureases were observed, indicating that this isolate has the capability to digest plant cell wall proteins and recycle nitrogenous waste under periods of nutrient limitation. Additionally, several laccases, peroxidases, and enzymes involved in extracellular hydrogen peroxide production previously implicated in lignin depolymerization were detected. In vitro biochemical assays were conducted to corroborate MudPIT results and confirmed that cellulases, glycosyl hydrolases, xylanases, laccases, and Mn- independent peroxidases were active in culture; however, lignin- and Mn- dependent peroxidase activities were not detected While little is known about the role of filamentous fungi and their associations with insects, these findings suggest that this isolate has the endogenous potential to degrade lignocellulose and extract nutrients from woody tissue

    Efficiency of Penicillium canescens in Dissipating PAH in Industrial Aged Contaminated Soil Microcosms and Its Impact on Soil Organic Matter and Ecotoxicity

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    The filamentous fungus Penicillium canescens, isolated from oil-polluted soil, was evaluated for its ability to dissipate high-molecular-weight polycyclic aromatic hydrocarbons (PAH). The study was conducted in a microcosm containing 180 g of historical PAH-contaminated soil under non-sterile conditions with two incubation temperatures (14 °C and 18 °C) on a 12-h cycle. The experiment was conducted over 8 months, with four experimental conditions created by varying the volumes of the bulking agent and vegetable oil (olive oil) and the time of addition of these compounds. The PAH dissipation performance of the fungal augmentation treatment was compared with that achieved with a biostimulated soil (bulking agent and vegetable oil) and with the untreated soil as control. The greatest PAH dissipation was obtained with P. canescens bioaugmentation (35.71% ± 1.73), with 13 of the 16 US EPA PAH significantly dissipated, at rates above 18%, and particularly high-molecular-weight PAH, composed of more than three fused aromatic rings. Nematode toxicity tests indicated a significant decrease in the toxicity of soil bioaugmented by this fungus. Fulvic and humic contents were significantly increased by this treatment. All these results suggest that bioaugmentation with P. canescens can be used to restore soils with long-term PAH contamination

    Mode d'action des antimalariques: role des proprietes acido-basiques des amino-4-quinoleines dans leur mecanisme de concentration intraparasitaire

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    SIGLEINIST T 75341 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

    Intérêt des champignons telluriques dans des processus de bioremédiation de sols pollués par des hydrocarbures aromatiques polycycliques

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    Polycyclic aromatic hydrocarbons (PAH) are ubiquitous and persistent pollutants that cause great environmental and health concern, because of their genotoxic and carcinogenic properties. Among the processes whereby these compounds are removed from the environment, microbial degradation plays a major role in the remediation of contaminated sites. Numerous biodegradation studies have been done on fungi, especially on various white rot fungi such as Phanerochaete chrysosporium, under in vitro and in vivo conditions. The installation of these foreign fungi in non-sterile soils is quite hazardous due to intense negative interactions with indigenous soil microorganisms. Optimising the degradation of PAH by the indigenous microbial community that had already been adapted to the soil habitat would be probably more economical and equally efficient. In our studies, we focused therefore on the ability of telluric fungi for PAH field bioremediation processes. In particular, we isolated a Deuteromycete fungus Fusarium solani that was able to grow in liquid medium with benzo[a]pyrene as sole carbon source and to mineralise this PAH. In a batch fermentor, [7,10-14C]benz[a]pyrene mineralization occurred rapidly at early stages of fermentation (15 hr) during the germination of fungal spores and was not a continuous process as mineralization occurred in a biphasic pattern. Moreover, Fusarium solani showed an average rate of mineralization about 65 μg/g dry weight/day within 11 days of incubation, comparable as mineralization rate obtained with a white rot fungus Phanerochaete chrysosporium.Les hydrocarbures aromatiques polycycliques (HAP) sont des polluants ubiquistes et persistants dont certains posent de réels problèmes pour l'environnement et la santé publique. Parmi les différentes techniques de réhabilitation actuellement disponibles, la bioremédiation s'est développée lors de ces dernières décades comme une alternative rentable et prometteuse. De nombreuses études ont mis en évidence l'aptitude des champignons de type lignolytique à dégrader les HAP. Cependant, l'origine non tellurique de ces champignons les rend peu compétitifs par rapport à la microflore endogène du sol. Dans une optique de bioremédiation, nous avons conduit des travaux de recherche afin d'utiliser le potentiel biotechnologique de champignons telluriques et en particulier de Fusarium solani
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