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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.
1

FIELD IMPLEMENTATION OF <em>PHANEROCHAETE CHRYSOSPORIUM</em> BIOMASS PRETREATMENT: FUNGAL IDENTIFICATION AND INOCULATION TECHNIQUES

Carey, Bobby D, Jr 01 January 2014 (has links)
Scaling biological pretreatment from the bench scale to the production scale may be more economical if unsterilized feedstock are used, however these allow for microbial competition from contaminates. An accurate and rapid method for identifying the desired biological pretreatment organism is necessary to confirm the presence of the desired organism when contaminates are morphologically similar to the target organism. Traditional methods, such as visual identification, sequencing, and selective plating can be time consuming and are sometimes still inconclusive. Based on methods described in the literature, plasmid DNA containing the marker genes gus (�-glucuronidase), LacZ, and gfp (green fluorescence protein) incorporated into the lignin-degrading basidiomycete Phanerochaete chrysosporium would result in a rapid genetic test for the desired organism. The presence of these genes can be confirmed either through an X-Gluc (cyclohexylammonia salt), X-Gal histochemical assay or observing the gfp’s fluorescence by a specially equipped confocal microscope. Each reporter systems will allow for rapid, reliable identification of the target species. This study will report on the success of the transformation methods in creating a transformed fungus to be used in the context of a large-scale fermentation operation. Additionally, a novel in-harvest lignocellulose feedstock biological pretreatment inoculation trial was performed comparing lignolytic performance between fungal inoculum application techniques. Optimization of carbohydrate availability for enhanced saccharification was determined by analyzing glucose release by treated and non-treated unsterilized switchgrass. This study also focused on identifying parameters to enhance saccharification efficacy at the farm-scale.
2

THE EFFECTS OF INOCULUM SIZE, AIRFLOW RATE, BULK DENSITY AND PARTICLE SIZE ON THE SCALE-UP OF <em>PHANEROCHAETE CHRYSOSPORIUM</em> PRETREATMENT

Hickman, Amanda N 01 January 2015 (has links)
The following full-factorial study compared fungal activity on lignocellulosic biomass that was inoculated with three different amounts of fungus, and grown using three different airflow rates. These treatments were compared to a control which consisted of biomass that was not inoculated but was exposed to the same growth conditions in the environmental chamber. The objectives of the following experiment were to determine the inoculum density and airflow rate required to optimize Phanerochaete chrysosporium lignin degradation. Additionally, this study quantifies the saccharification yield from the pretreated switchgrass. The impact of substrate bulk density and substrate particle size on fungal growth were compared to determine if the particle size or the substrate bulk density has the predominant influence on the growth of the fungus, and subsequent pretreatment effectiveness quantified as an increase in glucose yields and lignin degradation. The particle size tests were controlled for bulk density; all three particle sizes were tested at a bulk density of 80 kg/m3. To test the density, three different bale densities were prepared controlling for particle size. The density tests were performed on small-scale bales made of 4 inch cut pieces of switchgrass compressed to the correct density. Therefore; density tests had the same particle size throughout all treatments, and particle size tests had the same density through all treatments. Carbohydrate accessibility post-pretreatment was examined through enzymatic saccharification and determination of glucose yields in the treatments and controls.
3

INVESTIGATION OF PHANEROCHAETE CHRYSOSPORIUM AND CLOSTRIDIUM THERMOCELLUM FOR IMPROVED SACCHARIFICATION OF LIGNOCELLULOSE UNDER NONSTERILE CONDITIONS

Simon, William E. 01 January 2015 (has links)
Current research efforts are directed at developing competitive processes that can utilize lignocellulose as a feedstock for biorefineries. The purpose of this study was to investigate methods of processing lignocellulosic material so that its monosacharides can be more easily accessed for fermentation, the lack of which is hindering the economics and widescale adoption of lignocellulosic biorefining. The monosaccharides are of interest because they can be used by Clostridium beijerinckii downstream of P. chrysosporium and C. thermocellum in a sequential bioprocess to produce butanol. Butanol is an attractive biofuel because it can be utilized without modifying current transportation infrastructure. Butanol is also used as a starting material in organic synthesis. In the first study, the potential for C. thermocellum' s (ATCC 27405) cellulase system to operate outside its optimal temperature range in a high-solids environments was assessed by quantification of the fermentation products lactate, acetate, and ethanol and by quantification of xylose, glucose, and cellobiose remaining. Additionally, the lignin degrading white-rot fungus Phanerochaete chrysosporium RP 78 was investigated as a potential pretreatment for lignocellulose. Elevated temperatures required for Clostridium thermocellum fermentation were examined as a means to improve poor competiveness that is characteristic of P. chrysosporium on unsterile corn stover substrate.
4

Enzimas lignocelulolíticas de basidiomicetos cultivados em biomassas vegetais oriundas da agroindústria do dendê e obtenção de açúcares fermentescíveis

Peláez, Rubén Darío Romero 31 May 2017 (has links)
Três resíduos vegetais da agroindústria do dendê foram usados como substrato para o cultivo de distintas linhagens de fungos da podridão-branca (basidiomicetos). Foram avaliados o crescimento e produção de enzimas lignocelulolíticas por fermentação em estado sólido e submerso. Os extratos enzimáticos obtidos das fermentações foram utilizados no processo de hidrólise enzimática de bagaço de cana-de-açúcar e cacho vazio do dendê previamente pré-tratados. Um total de 54 linhagens de macrofungos foram cultivadas em três formulações de biomassa de dendê em placas Petri, onde foram escolhidas 5 linhagens com crescimento mais rápido e denso. Estas cinco linhagens de macrofungos foram cultivadas em fermentação em estado sólido e avaliados pelas atividades enzimáticas dos extratos obtidos. Nestes extratos, houve predominância das atividades de lacase, peroxidase, manganês peroxidase e protease. Das cinco linhagens foram selecionadas três linhagens com predominância nas atividades oxidativas nos cultivos em fermentação em estado sólido, para serem avaliadas em fermentação submersa (monocultivos) usando meio sintético suplementado com biomassa vegetal do dendê. As atividades enzimáticas das três espécies de basidiomicetos foram comparadas com cinco linhagens fúngicas usadas frequentemente na literatura. Houve diferenças significativas em função das atividades oxidativas (lacase e peroxidases) e hidrolíticas (FPase e β-glicosidases) entre as linhagens testadas. Estas diferenças foram usadas para estabelecer subgrupos, os quais foram avaliados através da interação em placa e cocultivos em fermentação submersa. As atividades enzimáticas dos extratos obtidos de monocultivos e cocultivos apresentaram diferenças com interações predominantemente positivas entre os três basidiomicetos e T. reesei ATCC® 60787. Os monocultivos e cocultivos foram comparados em função da liberação de glicose após da hidrólise enzimática de bagaço de cana-de-açúcar pré-tratado por autohidrólise. As hidrólises enzimáticas aplicando os extratos dos cocultivos obtiveram rendimento 44,7% superior quando comparadas com os monocultivos. Foi feita uma análise de misturas simplex lattice, usando como componentes os extratos dos monocultivos para a obtenção de um coquetel enzimático a fim de otimizar a liberação de glicose do bagaço de cana pré-tratado. Os resultados demostraram que os extratos com maiores atividades hidrolíticas estão correlacionadas com a maior liberação de glicose, e que os extratos com enzimas oxidativas podem melhorar o rendimento, tendo assim uma mistura ou coquetel caracterizado com enzimas hidrolíticas e oxidativas com potencial para obtenção de açúcares. Finalmente, este coquetel foi utilizado na hidrólise de cacho vazio de dendê pré-tratado fisicamente, biologicamente e biológica-físicamente (combinado) obtendo um rendimento máximo de 11,8 g.L-1 de glicose a partir de biomassa vegetal de dendê quando pré-tratada biológicafisicamente, o que correspondeu entre 40 - 60% do rendimento do rendimento obtido quando empregadas as enzimas comerciais Cellic® Ctec3 e Cellic® Ctec2. / Three vegetable residues from the palm oil industry were used as substrate for cultivation of different white rot fungi strains (basidiomycetes). The growth and production of lignocellulolytic enzymes were evaluated by solid and submerged fermentation. The enzymatic extracts obtained from fermentations were used in enzymatic hydrolysis process of pretreated sugarcane bagasse and oil palm empty bunch. Fifty-four macrofungal strains were cultivated in three formulations of oil palm biomass on Petri dishes, where 5 strains with faster and dense growth were chosen. These five macrofungal strains were cultivated in solid state fermentation and evaluated by the enzymatic activities of the extracts obtained. In these extracts, activities of laccase, peroxidase, manganese peroxidase and protease were found to be predominant. Three of the five strains were selected with predominance in oxidative activities on solid state fermentation cultures to be evaluated in submerged fermentation (monocultures) using synthetic medium supplemented with oil palm biomass. The enzymatic activities of the three basidiomycetes srtains were compared with five fungal strains frequently used in the literature. There were significant differences in function of the oxidative activities (laccase and peroxidases) and hydrolytic activities (PFase and β-glucosidases) among the tested strains. These differences were used to establish subgroups which were evaluated through the interaction in plates and cocultures in submerged fermentation. The enzymatic activities of the extracts obtained from monocultures and cocultures presented differences, with predominantly positive interactions between the three basidiomycetes and T. reesei ATCC® 60787. Monocultures and cocultures were compared as a function of the glucose release after the enzymatic hydrolysis of sugarcane bagasse pretreated by autohydrolysis. The enzymatic hydrolysis of the coculture extracts obtained higher percentages (maximum value 44.7%) when compared to monocultures. An analysis of simplex lattice mixtures was made using the monoculture extracts as components to obtain an enzymatic cocktail in order to optimize the glucose release of the pretreated sugarcane bagasse. The results showed that extracts with higher hydrolytic activities are correlated with the higher glucose release and extracts with oxidative enzymes can improve the sugar yield, thus having a mixture or cocktail characterized by hydrolytic and oxidative enzymes with the potential to obtain sugars. Finally, this cocktail was used in the hydrolysis of untreated, physically, biologically and biologically-physically (combined) pretreated oil palm empty bunch, obtaining a maximum yield of 11.8 gL-1 of glucose in the biomass of palm oil when pretreated biological-physically, which corresponded between 40-60% of the yield of the commercial enzymes Cellic® Ctec3 and Cellic® Ctec2.
5

Investigation of solid-state fungal pretreatment of Miscanthus for biofuels production

Vasco Correa, Juliana January 2017 (has links)
No description available.
6

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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