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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

Albumin Adsorption: Inferences of Protein Interactions Measured by Sedimentation both Between Species and Induced by Denaturing

McKeon, Kristin Dianne 20 May 2008 (has links)
Biological development and progression are managed by a diverse macromolecular group called proteins. Protein structure results from a complex folding process that leads to a final active form. This protein state is susceptible to changes in the surrounding environment and an incorrect structure can be produced. Changes in the protein conformation can lead to the formation of protein aggregates. Adsorption of proteins onto surfaces is utilized in many research analyses, but is capable of irreversibly changing the protein structure and causing aggregation. Albumin is a plasma protein that adsorbs on many different surfaces because the structure easily rearranges. The structure of albumin once adsorbed has been shown to deteriorate; however, outcomes of both stabilization and aggregation have been found. A dynamic laser light scattering instrument will be utilized to measure the differences in size and determine the amount of aggregation. Our lab has developed a z-axis translating laser light scattering device (ZATLLS) that has been used to measure the sedimentation velocity of several different materials in solution. In this case, bovine serum albumin (BSA) will be adsorbed onto polystyrene particles and the particle settling velocity determined. The settling solution viscosity and density will also be ascertained, so Stoke's law can infer the average aggregate size of each experiment. BSA-coated polystyrene particles displayed a more controlled settling behavior compared to non-coated polystyrene particles. Although the BSA-coated particles had a smaller sedimentation velocity, a larger aggregate size was found due to the greater solution viscosity. Therefore, the ZATLLS instrument can be employed to measure sedimentation velocities of multiple interactions and the aggregation level inferred. Although most albumin molecules are remarkably similar, there are subtle differences in amino acid residues, length, and charge. Sedimentation velocities for human serum albumin (HSA) coated polystyrene particles and BSA-coated polystyrene particles only had a small difference. However an almost 50% higher solution viscosity was measured in BSA experiment solutions, and resulted in the slower settling of the larger aggregates compared to HSA-coated particles. Viscosity calibration curves for each albumin species were used to determine the amount of protein desorbed from the particles during the settling process. The larger solution viscosity for BSA-coated particle experiments led to a much larger degree of desorption. HSA was shown to be the more stable albumin species when adsorbed onto polystyrene particles. Temperature denaturing was performed to aid in the determination of the stability of BSA. Reversible and irreversible conformational changes in BSA were produced at 46ºC and 76ºC respectively. The solutions were cooled to room temperature before adsorption ontopolystyrene particles and the sedimentation velocities measured. A 50% difference in average viscosity between the reversibly and irreversibly changed BSA was found. This caused the larger aggregates formed in the 76ºC BSA experiments to have an almost equivalent sedimentation velocity to those in the reversibly denatured BSA experiments. Average aggregate size for reversibly denatured BSA was well within the ranges found for non-denatured BSA. In conclusion, irreversibly denatured BSA formed larger aggregates and was more likely to desorb from the polystyrene particles than reversibly changed BSA. / Master of Science
2

Study on bacterial flora in liver-kidney-spleen of diseased cobia and grouper with bacteria infection.

Lai, Yueh-Yen 09 November 2005 (has links)
The fish disease epidemiology is urgent to be investigated for the surveillance and prevention. The diseased fish showed splenomegaly with diffusion of white nodules and microscopical granulomatous formation. It is important to develop a method of pathogens isolated from clinical samples with serial dilution method and disc diffusion method. Representative colonies were selected from diseased cobia on BHIA plate and were inoculated onto MacConkey agar, TCBS agar, and blood agar. The cage-culture of the different bacterial groups detected in the survey of bacteria isolated from THOD, HDSB, EMD with serial dilution method. 119 from 128 isolated strains were Gram¡¦s negative (93%), including pathogenic Vibrio spp. 57% (73/128) in THOD. 54 from 90 isolated strains were Gram¡¦s negative (60%), including pathogenic Vibrio spp. 12.2% (11/90) in HDSB. 61 from 104 isolated strains were Gram¡¦s negative (59%), including pathogenic Vibrio spp. 70.2% (77/90) in EMD. In different times diseased grouper, 104 from 139 isolated strains were Gram¡¦s negative (75%), including pathogenic Vibrio spp. 88% (123/139), in 2003. While 24 from 44 isolated strains were Gram¡¦s negative (55%), including pathogenic Vibrio spp. 73% (32/44), in 2004. 66 from 75 isolated strains were Gram¡¦s negative (88%), including pathogenic Vibrio spp. 97% (73/75) by disc dilution method in EMD. 9 from 31 isolated strains were Gram¡¦s negative (30%), including pathogenic Vibrio spp. 26% (8/31), by disc dilution method of grouper in PCG. A DGGE (denaturing gradient gel electrophoresis) technique can identify six groups of bacteria from cobia, and J6, R13, T29 have similarity 100%. Quantity One Version 4.5 (Bio-Rad) can identify six groups of bacteria from diffusion methods that F group diluted the bacterial strain from serial dilution method. B group and E group diluted the bacterial strain from disc diffusion method. Higher resistance rates of the different bacterial strains isolated from cobia and were £]-lactam and susceptible were observed in quinolones.
3

The use of pLysB19, a new plasmid, for in vitro transcription of milligram quantities of human lysyl tRNA and purification by urea denaturing PAGE

Marei, Mohamed M. 04 December 2009 (has links)
No description available.
4

Using of PCR-DGGE Technique to Analyze the Microbial Diversity in Biofiltration System of Water Treatment Plant

Shiu, Chih-ping 23 August 2007 (has links)
This study investigated the microbiota in ten different drinking water treatment pools, particles in the Biological Activated Carbon Filtration (BACF) bed, and two mimic columns in the Cheng-Ching Lake Water Treatment Plant. Assimilable organic carbon (AOC) is one of the main nutrition sources for microbes to survive in tap water. Over growing microbes not only decrease the water quality, but also contaminate the water treatment system and distribution system. In this study, we used two molecular biology techniques, the polymerase chain reaction (PCR) and denaturing gradient gel electrophoresis (DGGE), to analyze the dynamic microbial communities and biodiversities in the drinking water cleaning system and the micorbiota that exist in the BAC and anthracite filtration pellets. The bacterial 16S rDNA sequences resulted from PCR-DGGE were compared with the data in the Ribosomal Database Project Bank to construct a phylogenetic tree which allowed us to understand the microbial communities and biodiversities in the drinking water treatment pools and the filtration pellets. The total bacterial count and PCR-DGGE profiles showed that the drinking water quality had been improved during the treating processes and most of the microbes in raw water were removed. The scanning electron microscopy clearly indicated the biofilms were developed on the pellet surface. From the mimic column studies, the PCR-DGGE profiles suggested that various microbial communities were present on different depth of the columns samples. In comparing the 16S rDNA sequences with Gene Bank, many are new category bacteria were found and most of them are unculturable. Most of these microbes belong to the beta-proteobacterium. Although many bacteria were located on the surface of the filtration pellet, the BAC and anthracite could still absorb AOC efficiently to enhance the bacteria growth. The over growing bacteria might release out and contaminate the drinking water. Therefore, we suggest that it is important to backwash the filter bed frequently in order to diminish microbes of the filtration pellet and avoid re-contaminate the drinking water.
5

Bacterial diversity in the gastrointestinal tracts of four animals with different feeding habits

Tsao, Fu-jui 26 July 2011 (has links)
The animal phylogeny and feeding habits would affect the composition of gastrointestinal tract¡]GI tract¡^microbiota. GI tract microbiota plays an important role in host health and nutrient provision. In this study, we used PCR-DGGE and bacterial 16S rDNA sequencing to analyze the GI tract bacterial diversity of four animals with different feeding habits in Shou-Shan zoo, including one carnivore, one omnivore and two herbivores, in which one ruminant and one non-ruminant. The results show a great difference between GI tract bacterial diversity of the four animals. The abundance of GI tract bacterial diversity increased from carnivore, omnivore to herbivore. Comparing the similarity of the GI tract bacterial community structures of these four animals, the carnivore possessed the most different composition, to other animals, the next was the omnivore, while the two herbivores show the highest similarity to each other. Our results also indicated that the GI tract microbiota of these four different animals were very stable during the investigating period. We also found that two individuals of the same species had a very similar bacterial compositions in their GI tracts at different time point. This finding indicated that the bacterial compositions of GI tract in the four animals were affected mostly by the host phylogeny and their feeding habits. Moreover, according to bacterial 16S rDNA sequencing and idencification, results show that the Firmicutes were the dominant bacterial phyum in all four animals GI tracts, the amount of Bacteroides was much less than Firmicutes. This result might caused by the highly starch content in their feed. Large amount of carbohydrate-degrading, protein-degrading, lipid-degrading bacteria were found in all of these different animals. Fiber-degrading bacteria Fibrobacteres were identified in the GI tracts of the herbivores and omnivore, but not the carnivore, showing that GI tract microbiota plays an important role to provide nutrient and assist energy to the host.
6

Application of ex-situ bioremediation to remediate petroleum-hydrocarbon contaminated soils

Wang, Sih-yu 23 August 2012 (has links)
Leaking of petroleum products from storage tanks is a commonly found cause of soil contamination. Among those petroleum products, diesel-oil contaminated soils are more difficult to treat compared to gasoline (a more volatile petroleum product). With the growing interest in environmental remediation, various approaches have been proposed for treating petroleum-hydrocarbon (PH) contaminated sites. Given that it is often not possible to remove the released oil or remediate the site completely within a short period of time, using the in situ remedial technology, soil excavation followed by more cost-effective technology should be applied to accelerate the efficiency of site cleanup. In the first-part of this study, laboratory degradation experiments were conducted to determine the optimal operational conditions to effectively and economically bioremediate diesel-fuel contaminated soils. In the second part of this study, a combined full-scale landfarming and biopile system was operated to cleanup diesel fuel-contaminated soils. In the laboratory study, except of frequent soil tilling for air replacement, different additives were added in the laboratory bioreactors to enhance the total petroleum hydrocarbon (TPH) removal efficiency. The additives included nutrients, TPH-degrading bacteria, activated sludge, fern chips, and kitchen waste composts. PH-degrading bacteria were isolated from PH-contaminated soils and activated sludge was collected from a wastewater treatment plant containing PH in the influent. PH-degrading bacteria and sludge were added to increase the microbial population and diversity. Fern chips and kitchen waste composts were added to increase the soil permeability. Results indicate that the bioreactor with kitchen waste compost addition had the highest TPH removal rate. The observed TPH-removal ratios for the compost, activated sludge, PH-degrading bacteria, fern chips, nutrients, TPH-degrading bacteria addition, and control (with HgCl2 addition) groups were 80.5%, 78.6%, 77.4%, 75.1%, 73.3%, 66.1%, and 1.6% respectively. In the field study, activated sludge was selected as the additive from the engineering point of view. With the addition of activated sludge, an increase of 20% was observed for TPH removal ratio. Results from the denaturing gradient gel electrophoresis (DGGE) tests show that the detected PH-degrading bacteria in the activated sludge included the following: Pseudomonas sp., Pseudoxanthomonas sp., Rhodocyclaceae bacterium, Variovorax sp., Acidovorax sp., Leptothrix sp., Alcaligenaceae bacterium, and Burkholderia sp. Some of these bacteria became dominant species in the field after a long-term operation, which was beneficial to the soil bioremediation. Results indicate that the in situ bioremediation has the potential to be developed into an environmentally and economically acceptable remediation technology.
7

The bacterial diversity in a KaoPing River constructed wetland for wastewater treatment

Cheng, Shu-Hsun 14 July 2008 (has links)
Constructed wetlands had been used for water treatment worldwide. The efficiency of wastewater treatment in a constructed wetland depends on its design, types of aquatic plants and microbial community present in this wetland. The goal of this study is to analyze the microbial populations in KaoPing River Rail Bridge constructed wetland which was designed to remove the polluted material from municipal sewage and industrial wastewater. Sediment and water samples were collected every 3 months from April, 2007 to April, 2008. The bacterial community diversities were analyzed by PCR-DGGE of the bacterial 16S rRNA gene. Results show approximately 60% BOD, 41% COD, 46% nitrate, 22% total nitrogen, and 97% coliforms were removed by this wetland system. DGGE profiles revealed the bacterial community diversities shifted progressively from the entry to the exit of both A and B systems in this wetland. The microbial populations in water, sediment, biofilms on plants, and soil were quite different from each others. The fecal indicator Escherichia coli was used as a marker to monitor the fecal contamination in all samples. From PCR-DGGE profiles, E. coli could be successfully removed by this wetland system. In conclusion, this constructed wetland is a very successful system for wastewater treatment and is able to remove most of the pollutants before they are discharged into KaoPing River. The results of this study provided useful suggestions for the government to assess the bacterial diversities and the efficiency of this wetland system, to protect people from hazardous risks, and to manage a constructed wetland in the future.
8

Studies of the Diversity of <em>Lactobacillus spp</em>. in Fecal Samples Using PCR and Denaturing Gradient Gel Electrophoresis

Strandgren, Charlotte January 2008 (has links)
<p>Allergic diseases, for example asthma and eczema, are nowadays considered belonging to the most common chronic diseases amongst children in the West, but the cause for this increase in allergy prevalence is unknown. Since studies have indicated a connection between children's exposure of microorganisms during infancy and risk of developing allergic disease, it is suggested that this exposure is a crucial factor in question of allergy development or not. Other studies have established differences in microflora composition between healthy children and children with allergic disease, and several studies have shown that probiotic therapy can give positive results in both prevention and treatment of allergic diseases.</p><p>The aim of this master's thesis was to develop a method, using PCR and denaturing gradient gel electrophoresis, to study the diversity of <em>Lactobacillus spp</em>. in fecal samples retrieved from a study of the probiotic strain<em> L. reuteri</em> ATCC 55730. The developed method was successful in detecting lactobacilli in fecal samples, but three other bacterial genera commonly found in humans were also amplified. Comparison of average numbers of detected bacterial strains and lactobacilli strains between samples belonging to the probiotics and placebo groups, respectively, showed higher numbers for the probiotics group. Also, the only fecal samples that contained <em>L. reuteri</em> belonged to the probiotics group. Although the results are far from statistically significant, they support the theories that probiotics may influence the intestinal microbiota.</p>
9

Molekulargenetische Diagnostik des ATRX-Syndroms mittels Denaturing High-Performance Liquid Chromatography (DHPLC)

Junge, Cornelia 07 July 2014 (has links) (PDF)
Die DNA-Sequenzierung nimmt in der molekulargenetischen Diagnostik seit vielen Jahren einen großen Stellenwert ein. Zeit- und kosteneffektivere Methoden wie die DHPLC wurden seither für verschiedene Gene etabliert. Ziel dieser Arbeit war die Etablierung der DHPLC für das ATRX-Gen bei Patienten mit Verdacht auf das ATRX-Syndrom. Nach erfolgreicher Etablierung der DHPLC sollten im Rahmen dieser Arbeit 38 Patientenproben des Instituts für Humangenetik der Universität Leipzig mit Verdacht auf das ATRX-Syndrom mittels DHPLC und Sequenzierung untersucht werden. Die Etablierung der DHPLC gelang in der vorliegenden Arbeit für alle - das ATRX-Gen vollständig umspannenden - 42 Fragmente. Jede der vorliegenden Sequenzvariationen konnte nach Abschluss der Arbeit detektiert werden. Unter Verwendung von Maxima® stellten sich initial 22 von 24 verschiedenen Sequenzvariationen zum Wildtyp different dar. Die verbleibenden zwei Mutationen p.R246C und p.A238P im Fragment 9 wurden unter Verwendung höherer Temperaturen, eines kürzeren Fragmentes oder anderer Polymeraseenzyme (AmpliTaq Gold® bzw. HighFidelity) detektiert. Nach Abschluss der Etablierung der DHPLC konnte eine Sensitivität und Spezifität von 100% erreicht werden. In den Patientenuntersuchungen des Instituts für Humangenetik der Universität Leipzig fanden sich bei 38 Patientenproben vier verschiedene als benigne beschriebene Polymorphismen bei insgesamt 19 Patienten, ein noch nicht veröffentlichter Polymorphismus im Intron 26 sowie eine bis dato nicht beschriebene und als pathogen einzustufende Mutation im Exon 34. In 100 Kontrollen der DNA-Bank des Instituts für Humangenetik der Universität Leipzig konnte der bisher nicht publizierte Polymorphismus im Intron 26 sieben Mal gefunden werden. Die bis dato nicht beschriebene Deletion p.2385_2395del im Exon 34 führt zu einem vorzeitigen Abbruch des ATRX-Proteins und ist somit als sicher pathogen einzustufen. Die Untersuchung der Mutter des Patienten konnte den Konduktorenstatus nachweisen. Für die Familie des betroffenen Patienten konnte mit der vorliegenden Arbeit die Diagnose des ATRX-Syndroms gesichert werden. Die DNA-Proben der Patienten bei denen keine Mutation nachgewiesen werden konnte, sollten bei weiterhin dringendem Verdacht auf das ATRX-Syndrom mittels qRT-PCR bzw. MLPA untersucht werden, um große Deletionen, Insertionen oder Duplikationen auszuschließen. Mithilfe dieser Arbeit gelang die Etablierung der DHPLC für das ATRX-Gen als ökonomische, sehr sensitive und effiziente Methode zur Diagnostik des ATRX-Syndroms. Die Entscheidung, in welcher Form und mit welcher Methode DNA-Proben bei Verdacht auf ATRX-Syndrom untersucht werden, bleibt jedoch eine individuelle Entscheidung jedes Instituts unter Betrachtung der jeweiligen Gegebenheiten vor Ort.
10

Molecular Characterization of Toxic Cyanobacteria in North American and East African Lakes

Chhun, Aline January 2007 (has links)
Toxic cyanobacterial blooms constitute a threat to the safety and ecological quality of aquatic environments worldwide. Cyclic hepatotoxin, especially microcystin, is the most widely occurring of the cyanotoxins. The aim of this study was to identify the cyanobacterial genotypes present including how many toxic genotypes were present in two North American lakes and one African Lake. All three lakes are prone to cyanobacterial blooms and were sampled in 2005 and 2006: Lake Ontario (Bay of Quinte, Canada), Lake Erie (Maumee Bay, Canada) and Lake Victoria (Nyanza Gulf, Kenya). The cyanobacterial genotypic community was assessed using DNA based analyses of the hypervariable V3 region of the 16S rRNA gene. In addition, the aminotransferase (AMT) domain in modules mcyE and ndaF of the microcystin and nodularin gene cluster respectively was used to detect the presence of hepatotoxic genotypes. Denaturing gradient gel electrophoresis (DGGE) results from this study suggested that hepatotoxin producers were present in all study sites sampled and were most likely members of the genus Microcystis. This study was the first to report the potential for microcystin production in the in-shore and off-shore open lake of Nyanza Gulf in Kenya. A seasonal study of the Bay of Quinte and Maumee Bay showed differences in the cyanobacterial genotypic community from early to late summer. In addition, the cyanobacterial genotypic community from the Bay of Quinte differed from 2005 to 2006 and quantification of the North American samples revealed an increase in cyanobacterial cells from early to late summer. The Bay of Quinte saw relatively no change in hepatotoxic cells from early to late summer but in Maumee Bay hepatotoxic cells increased from undetectable in early summer to dominating the cyanobacterial community by late summer. This study demonstrated the use of DGGE and qPCR of the 16S rRNA-V3 and AMT gene region in monitoring the cyanobacterial community of waterbodies susceptible to toxic cyanobacterial blooms.

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