Добірка наукової літератури з теми "Dégradation fongique"
Оформте джерело за APA, MLA, Chicago, Harvard та іншими стилями
Ознайомтеся зі списками актуальних статей, книг, дисертацій, тез та інших наукових джерел на тему "Dégradation fongique".
Біля кожної праці в переліку літератури доступна кнопка «Додати до бібліографії». Скористайтеся нею – і ми автоматично оформимо бібліографічне посилання на обрану працю в потрібному вам стилі цитування: APA, MLA, «Гарвард», «Чикаго», «Ванкувер» тощо.
Також ви можете завантажити повний текст наукової публікації у форматі «.pdf» та прочитати онлайн анотацію до роботи, якщо відповідні параметри наявні в метаданих.
Дисертації з теми "Dégradation fongique":
Garon, David. "Dégradation fongique du fluorène (HAP) : optimisation et application aux sols." Université Joseph Fourier (Grenoble), 2002. http://www.theses.fr/2002GRE18002.
Saadi, Zoubida. "Etude de la dégradation fongique des polymères : cinétique de dégradation des polymères et caractérisation des sous-produits de dégradation : étude de l'écotoxicité de ces polymères." Le Mans, 2008. http://cyberdoc.univ-lemans.fr/theses/2008/2008LEMA1004.pdf.
Subject of current events, the biodegradability of polymers is always studied in a global context, that is to say, with regards to fungi and bacteria together. The present research project focuses on the purely fungal degradation of polymers. Apart from the core research, the results of this study suggest certain applications to reduce environmental problems : - to deteriorate materials with a specific fungal strain. - to better control the kinetics of the biodegradation of plastics (mulching films, packaging materials). - Accelerate bio-degradation. After selecting non-toxic fungi present in natural states (compost, soil) and verifying the inertness of PLLA and PBAT on fungal cultures, cellular growth tests in a glucose-free environment revealed a selectivity among fungi for certain polymeric substrata. The tests also highlighted the major role temperature plays in the fungal degradation of polymers. When temperatures get closer, or go beyond the glass transition temperature, the physical structures are more accessible to fungal enzymes. After determining fungal consortium in the degradation of PLLA and PBAT, respiration measurements in soil and compost, both sterilized then sowed, have confirmed temperature as the essential parameter of biodegradation. Taking place in unmodified soil and compost, the kinetics of biodegradation of these polymers revealed a fungi-bacterial synergy during biodegradation tests. This study of biodegradation – refined with a follow-up of the physical and chemical properties of the polymers – led to a better understanding of the various stages of hydrolysis as well as the mineralization of polymers. These investigations had to take into account the characterization of metabolizing products of PLLA and PBAT and a regular toxicity check for the environment
Rougemaille, Mathieu. "Interactions entre transcription, maturation et dégradation des ARNs chez Saccharomyces cerevisiae." Paris 11, 2007. http://www.theses.fr/2007PA112276.
In budding yeast Saccharomyces cerevisiae, the exosome is a large complex with 3’ to 5’ exonuclease activity that has been implicated in numerous RNA processing and degradation events. We have shown that several transcripts mapping to intergenic regions are rapidly degraded in a wild type strain by the combined action of the exosome and a novel complex called TRAMP, whose catalytic subunit is a poly(A) polymerase. We proposed that degradation of these RNAs, called CUTs for Cryptic Unstable Transcripts, is a mechanism required to limit inappropriate transcription or to allow the occurrence of transcription without RNA production. We have also demonstrated that transcription termination of CUTs is triggered by specific RNA-binding proteins, Nrd1p and Nab3p, which direct nascent transcripts to exosome/TRAMP-mediated degradation. The THO complex and its associated RNA helicase Sub2p are involved in mRNA biogenesis and couple transcription to mRNA export. Mutations in any of these genes lead to exosome-dependent degradation and retention of mRNAs at or near the transcription site. We have shown that the TRAMP complex is involved in mRNA degradation but not in retention. Furthermore, we observed that, in THO/sub2 mutants, a DNA-interacting complex containing polyadenylation factors and components of the Nuclear Pore Complex cannot be resolved for further mRNA export. Accordingly, the THO/Sub2p complex would be involved in a remodeling step required to displace the polyadenylation complex and to engage productively the mRNA in the export pathway
Barbi, Florian. "Impact de l’essence forestière sur les processus de dégradation et d’assimilation des polysaccharides végétaux par la communauté fongique des sols forestiers." Thesis, Lyon 1, 2015. http://www.theses.fr/2015LYO10347.
The degradation of plant biomass is an essential process for the proper functioning of forest soils and terrestrial carbon cycling. Mechanisms involved in these processes are strongly controlled by saprotrophic fungi which secrete several hydrolytic enzymes to access at their primary nutrient sources found under the form of polysaccharides (cellulose and hemicelluloses). Enzymatic hydrolysis of plant polymers releases a high diversity of low molecular weight compounds (mono- and oligosaccharides). These molecules enter in fungal cell using transmembrane transporter systems. Consequently, the presence/absence and the substrate specificity of these transporters might contribute to the metabolic versatility of soil fungi. Several studies have demonstrated that tree species strongly affect diversity and composition of fungal communities. In this context, we hypothesized that the fungal communities selected by the different tree species expressed specific lignocellulolytic enzymes and sugar transporters; and thereby each fungal community was specifically adapted to the nature of litter produced by the tree species considered. We assessed, by the high-throughput sequencing of gene-fragments amplified from soil cDNA, the impact of tree species (Beech vs Spruce) on the diversity of genes encoding either lignocellulolytic enzymes or sugar porters expressed by soil fungi in two mono-specific forests. Our results revealed that most detected genes, encoding either lignocellulolytic enzymes or sugar transporters, have an unknown origin and are specifically found (for more than 80% of them) in one of the two forest soils. This work showed a significant “tree species effect” on the composition of functional genes expressed by soil fungi and suggests that beyond the species level, functional diversity of fungal communities must be addressed to better understand ecosystem functioning. Moreover, by using a functional metatranscriptomic approach, we identified functional transporter sequences differing with respect to their substrate specificities. From a spruce cDNA library, and for the first time, we identified high affinity or mannose specific transporters. Coincidently, as opposed to beech, spruce is indeed a tree species with a large proportion of mannose in its hemicelluloses
Haddaoui, Asmaa. "Dégradation des pigments anthocyaniques des jus de fruits rouges par les activités [Bêta]-glycosidasiques présentés dans les préparations pectinolytiques industrielles d'origine fongique." Vandoeuvre-les-Nancy, INPL, 1995. http://www.theses.fr/1995INPL151N.
Hayar, Salem. "Influence d'un inoculum fongique, d'amendements organiques et minéraux sur la dégradation de l'atrazine : cas d'un sol présentant une microflore autochtone adaptée ou une faillibilité microbienne." Université Joseph Fourier (Grenoble), 1999. http://www.theses.fr/1999GRE18007.
Deroy, Aurélie. "Évolution et adaptation des champignons saprophytes : les systèmes impliqués dans la dégradation du bois chez Trametes versicolor." Thesis, Université de Lorraine, 2015. http://www.theses.fr/2015LORR0169/document.
Wood is one of the most abundant polymer resources of the Earth’s ecosystem. Wood decaying fungi play an important role in the carbon cycle. They have a strong interest in biotechnology level in particular for the production of enzymes. Among the saprophytic fungi, those of the class of agaricomycota are particularly studied since they possess the ability to degrade varous compounds from wood : cellulose, hemicelluloses dand lignin. In addition, these fungi have developed a detoxification system involving enzymes such as glutathione transferases (GST). These latter are involved in degradation of wood but also in the degradation of xenobiotics. In this manuscript, the study of extracellular and intracellular system from Trametes versicolor, involved in wood decay process is described, the main goal being to identify the molecular factors involved in adaptation of the to their environment. Multidisciplinary approaches used in this PhD led to identification of an intraspecific phenotypic variability among ten strains of T. versicolor, this variability appearing to be related to the tree species where these strains have been isolated. Moreover, the work done on GSTs belonging to GHR and omega classes have improved our knowledge of the involvement of this gene family in adaptating the wood decayers to thrit lifestyle
Lekounoungou, Serge-Thierry. "Evaluation et compréhension des mécanismes fongiques impliqués dans la dégradation du bois." Thesis, Nancy 1, 2008. http://www.theses.fr/2008NAN10027/document.
The study of enzymatic activities expressed during growth of the white rot fungus T. versicolor on malt agar medium in the presence of beech (Fagus sylvatica) wood chips was investigated. The process of wood degradation was divided in two stages. The first stage was characterized by the production of laccases and peroxidases activities. The second stage was characterized by production of carbohydrates hydrolyzing activities. At the beginning of wood colonization process, the production of laccases activities was correlated with degradation of wood acetonic extractives as catechin, which was easily identified in the beech extracts. The presence of a biocide like propiconazole is responsible of the induction of a strong chitinases activity at the beginning of the colonization process. Utilisation of caffeine, a chitinases inhibitor, in the presence of propiconazole allowed to reduce the quantity of biocide necessary to prevent wood from fungal degradation. Similarly, congo red, another cell wall perturbing agent, presented additive effect on inhibition of the fungal growth when associated to propiconazole. The application of the methods developed in this study to the case of heat treated beech wood highlighted the effect of this treatment on the expression of enzymatic activities during wood degradation process explaining in great part the improvement of durability observed after heat treatment
Hentges, David Jean. "Caractérisation de la composition chimique du bois par pyrolyse flash couplée à la GC/MS : application à l'étude de la variabilité naturelle et aux modifications résultant de différents traitements." Electronic Thesis or Diss., Université de Lorraine, 2022. http://www.theses.fr/2022LORR0321.
Analytical pyrolysis is an innovative method that allows gas chromatographic analysis of complex polymers by reducing them to volatile monomers. The method requires only a few milligrams of material and is performed in a few seconds. Wood is an abundant renewable material that is used in many forms, notably in construction, in fiberboard and in the extractives it containsNumerous chemical and thermochemical modification techniques are used to improve the properties of wood, including acetylation, furfurylation and heat treatment. Pyrolysis is a new technique to characterize treated wood to understand the chemical modifications that have been generated. The classical methods used such as NMR, FTIR do not allow for a complete picture of the wood, more specifically on elements such as the regioselectivity of the modifications. The aim of our work is to answer fundamental questions about the natural variability of wood as well as the chemical modifications generated by different methods. The polymerization of furfuryl alcohol in wood could be demonstrated as well as the formation of a covalent bond with lignin. The wood acylated with different linear anhydrides revealed new structures that allow to identify the reaction sites and to estimate the reactivity of macromolecules. The method is capable of quantifying the extent of modification of the different biopolymers that constitute the wood. Using principal component analyses (PCA), the natural variations of wood as a function of height, tissue and between different specimens of the same species could be characterized. Py-GC/MS was also used to show structural differences after heat and fungal treatment to reveal how these degradations affect the wood
Touzani, Abdellah. "Etude du complexe cellulasique de Botrytis cinerea et des autres enzymes exocellulaires impliquées dans la dégradation des parois cellulaires de la pellicule du raisin." Bordeaux 2, 1993. http://www.theses.fr/1993BOR20243.