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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Fungal Pigment Formation in Wood Substrate

Tudor, Daniela 14 January 2014 (has links)
A number of fungi produce spalted wood, which is characterized by accumulation of black pigment in fine demarcation lines, often accompanied by discoloration or staining on the wood fibers. Specific spalting fungi were identified by molecular analysis. From a total of 19 isolates and 140 clones studied, 11 fungal species were identified. The two Chlorociboria species from North America were investigated and their anamorphs were unambiguously identified for the first time. Fungal pigment formation under the influence of moisture content and pH variation was investigated in sugar maple, American beech and agar inoculated with spalting fungi. Maximum pigment production occurred at treatment with pH 4.5 for sugar maple and beech inoculated with Trametes versicolor. Xylaria polymorpha produced external pigmentation in beech treated with buffer at pH 5 and sugar maple at pH 4.5. Fungal pigmentation by Trametes versicolor and Xylaria polymorpha was stimulated at low moisture content in both wood species tested. Melanin production by Inonotus hispidus and Polyporus squamosus was stimulated above 22-28% and 34-38% moisture content in beech and in sugar maple respectively. Fomes fomentarius and Polyporus brumalis produced maximum pigmentation in beech at 26 - 41% and in sugar maple at 59 - 96% moisture content. The variation of the moisture content and pH values of wood substrates can stimulate the intensity of pigmentation of specific fungi in wood. To investigate melanin synthesis from a variety of melanin precursors, experimental research on three spalting fungi tested their reaction to catechol and L-Dopa melanin precursors in wood and agar substrate. The results indicate multiple biosynthesis pathways for melanin assembly in Trametes versicolor, Xylaria polymorha and Inonotus hispidus, and catechol produced most pigmentation in all spalting fungi investigated. Microscopic analysis by light, fluorescence, electron and confocal microscopy also indicates a bi- or multi-modal activity of melanin production and assembly by several spalting fungi. Possible variations of melanin assembly were identified based on fungal and wood species. Immunofluorescence and immunogold labelling with Mab 6D2 melanin antibody confirmed the melanin nature of the pigments produced by Oxyporus populinus, Trametes versicolor, Xylaria polymorpha, Fomes fomentarius, and Inonotus hispidus.
32

Fungal Pigment Formation in Wood Substrate

Tudor, Daniela 14 January 2014 (has links)
A number of fungi produce spalted wood, which is characterized by accumulation of black pigment in fine demarcation lines, often accompanied by discoloration or staining on the wood fibers. Specific spalting fungi were identified by molecular analysis. From a total of 19 isolates and 140 clones studied, 11 fungal species were identified. The two Chlorociboria species from North America were investigated and their anamorphs were unambiguously identified for the first time. Fungal pigment formation under the influence of moisture content and pH variation was investigated in sugar maple, American beech and agar inoculated with spalting fungi. Maximum pigment production occurred at treatment with pH 4.5 for sugar maple and beech inoculated with Trametes versicolor. Xylaria polymorpha produced external pigmentation in beech treated with buffer at pH 5 and sugar maple at pH 4.5. Fungal pigmentation by Trametes versicolor and Xylaria polymorpha was stimulated at low moisture content in both wood species tested. Melanin production by Inonotus hispidus and Polyporus squamosus was stimulated above 22-28% and 34-38% moisture content in beech and in sugar maple respectively. Fomes fomentarius and Polyporus brumalis produced maximum pigmentation in beech at 26 - 41% and in sugar maple at 59 - 96% moisture content. The variation of the moisture content and pH values of wood substrates can stimulate the intensity of pigmentation of specific fungi in wood. To investigate melanin synthesis from a variety of melanin precursors, experimental research on three spalting fungi tested their reaction to catechol and L-Dopa melanin precursors in wood and agar substrate. The results indicate multiple biosynthesis pathways for melanin assembly in Trametes versicolor, Xylaria polymorha and Inonotus hispidus, and catechol produced most pigmentation in all spalting fungi investigated. Microscopic analysis by light, fluorescence, electron and confocal microscopy also indicates a bi- or multi-modal activity of melanin production and assembly by several spalting fungi. Possible variations of melanin assembly were identified based on fungal and wood species. Immunofluorescence and immunogold labelling with Mab 6D2 melanin antibody confirmed the melanin nature of the pigments produced by Oxyporus populinus, Trametes versicolor, Xylaria polymorpha, Fomes fomentarius, and Inonotus hispidus.
33

Decolorization of an azo and anthraquinone textile dye by a mixture of living and non-living Trametes versicolor fungus

Dykstra, Christine M. 01 May 2011 (has links)
Wastewater from the textile industry is difficult to treat effectively due to the prevalent use and wide variety of synthetic dyes that are resistant to conventional treatment methods. White-rot fungi, such as Trametes versicolor, have been found to be effective in decolorizing many of these synthetic dyes and current research is focusing on their application to wastewater treatment. Although numerous studies have been conducted on the ability of both living and nonliving Trametes versicolor to separately decolorize textile dyes, no studies were found to have investigated the use of a mixture of live and dead fungus for decolorization. This study explored potential interactions between live and dead, autoclaved Trametes versicolor biomass in a mixed system by utilizing a series of batch tests with two structurally different synthetic textile dyes. Samples were analyzed by spectrophotometer and compared with controls to determine the effect of any interactions on decolorization. The results of this study indicate that an interaction between living and nonliving biomass occurred that affected the specific dye removal for both Reactive Blue 19, an anthraquinone textile dye, and Reactive Orange 16, an azo textile dye. This interaction was seen to improve the specific dye removal during the first 10-46 hours of experimentation but then diminish the specific dye removal after this period. This effect could be due to hydrophobins, which are surface-active proteins excreted by live fungi that may alter hydrophobicity. Additionally, the presence of adsorptive dead biomass could affect dye contact with degrading enzymes released from the live fungus. By expanding current knowledge of the interactions that take place in a fungal bioreactor and their effect on textile dye decolorization, this research aims to inspire more effective and less costly bioreactor designs for the treatment of textile wastewater.
34

Biological attack of acetylated wood / Biologischer Angriff von acetyliertem Holz

Mohebby, Behbood 03 May 2003 (has links)
No description available.
35

Možnosti eliminace sulfonamidů z vodního ekosystému / Possibilities of elimination of sulfonamides from the aquatic ecosystem

Suková, Petra January 2018 (has links)
This diploma thesis focuses on the determination of sulfonamide antibiotics especially the possibility of elimination of these substances from the aquatic ecosystem. Nowadays, environmental contamination of the pharmaceuticals and their residues is a serious concern. Main sources of this contamination are wastewater treatment plants (WWTPs), where these compounds are not effectively removed by contemporary conventional technology. For this reason, new methods are being developed and tested that could eliminate the number of contaminants entering the environment in this way. There is a possibility to use the potential of the enzymatic system of wood-decay fungi, especially white rot fungi. Six representatives of sulfonamide antibiotics were selected and isolated from the aquatic matrix via solid phase extraction. The final identification and quantification method was high performance liquid chromatography with mass spectrometric detection. Monitoring of the concentration level of selected sulfonamide antibiotics at the inflow and effluent at the Brno-Modřice WWTP was carried out weekly. Moreover, the effectiveness of elimination of selected antibiotics from the aquatic ecosystem by the use of Trametes versicolor wood-decay fungi cultured on a suitable carrier was verified.
36

Remoção do corante FD&C azul nº 2 Indigotina em água com uso de fungos de decomposição branca e processo de filtração lenta: avaliação em escala piloto / Remove the dye FD & C Blue No. 2 indigo in water use fungal decay and white slow filtration process: evaluation in pilot scale

LOPES, Maria Margareth Gonçalves 04 August 2008 (has links)
Made available in DSpace on 2014-07-29T15:01:40Z (GMT). No. of bitstreams: 1 maria margareth goncalves.pdf: 3073051 bytes, checksum: a405b4aae069912b1212db181d1858f8 (MD5) Previous issue date: 2008-08-04 / Industrial activities are constantly producing wastes such as dyes which are usually found in the industrial effluents and constitutes a environmental problem due its toxicity and inadequate disposal. The use of fungi, in particular the white-rot fungus, have been found to be efficient for biodegrading these compounds. In addition, slow sand filtration have been reported to be the most efficient unit filtration processes to improve the physical, biological and chemical quality of potable water. The objective of this work was to investigate the removal efficiency of the dye FD&C azul Nº 2 Indigotina, by the use of the Trametes versicolor fungus combined with slow sand filtration. Two laboratory-scale filter columns of 0.08 m diameter and 0.90 m sand media depth were used to investigate the process performance. One slow sand filter, FLA, was applied in combination with the Trametes versicolor fungus, while the FLB was used as control. Three methodologies for the fungi growth were used. The results showed that the slow sand filtration is a prominent process for the removal of the dye FD&C azul nº 2 Indigotina when used in combination with the Trametes versicolor fungus. A maximum removal of 95% was found when the filter was inoculated with fungi grown on Petri dish. The average dye removal when the increased fungi biomass was inoculated to the filter was 70%. This result suggests that the filter performance increased when the fungus was inoculated with fungi grown on Petri dish. In addition, head loss was found to be higher in the FLA filter than in the FLA (control), indicating that the fungi biomass contributes to the head loss development. / Nas atividades industriais geradoras de resíduos os corantes são amplamente encontrados nos efluentes, quase sempre, constituindo um problema de ordem ambiental devido à sua toxicidade. O uso de fungos na degradação de corantes vem sendo estudado em diversos trabalhos científicos enquanto as vantagens econômicas e ambientais do uso de filtros lentos na produção de água bacteriologicamente segura há muito tempo já está descrita por diversos autores. Este trabalho teve por objetivo investigar a eficiência da remoção de corante artificial FD&C azul nº2 Indigotina, com uso do fungo de degradação branca Trametes versicolor em combinação com a filtração lenta. Para isso, foram instalados dois protótipos de filtros lentos denominados FL-A e FL-B em escala laboratorial, sendo que o filtro FL-A, foi inoculado com o fungo e o filtro FL-B, utilizado como controle, não foi inoculado com fungo. Três procedimentos foram empregados para o cultivo do fungo. Os resultados mostraram que a filtração lenta tem grande potencial para remoção eficiente de cor quando empregada em conjunto com o fungo Trametes versicolor. O melhor percentual de remoção do corante FD&C azul nº2 indigotina pelo fungo Trametes versicolor em combinação com a filtração lenta foi de 95% na metodologia com adição da biomassa de cultivo do fungo correspondente a duas placas de Petri. A média de descoramento da metodologia com adição de biomassa aumentada do fungo foi de 70%. Em todas as carreiras de filtração as perdas de cargas no FL-A, inoculado com fungo, foram superiores às do FL-B de controle. Este resultado indica que a biomassa gerada pelos fungos contribue para o aumento da perda de carga nos filtros lentos.
37

Actions of lignocellulolytic enzymes on Abies grandis(grand fir) wood for application in biofuel production

Cherdchim, Banyat 27 October 2010 (has links)
No description available.

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