Acidithiobacillus ferrooxidans is an important industrial organism used in the mining industry where it participates in passive bioleaching processes used to produce about 20% of the world’s copper supply. The bacterium thrives in strong mineral acids at ambient temperatures and derives metabolic energy from the oxidation of ferrous iron, sulfur, and reduced inorganic sulfide compounds to fix CO2 and N2. This unique metabolism provides new opportunities to engineer this organism for the production of fuels and chemicals from CO2. While A. ferrooxidans has been studied extensively for 60 years, the tools and methods necessary for a robust genetic system to manipulate and further study this bacterium are not well developed and published techniques are generally difficult to reproduce. This research focuses on developing the means to genetically modify this species to experimentally study its physiology and engineer the organism for the production of chemicals from CO2. This includes developing a robust and reproducible system to generate and select mutant strains, heterologous expression of exogenous genes, characterizing endogenous inducible promoters, and developing new plasmids to expand the repertoire of tools available for this organism.

Typescript (photocopy). / Digitized by Kansas Correctional Industries

Thesis (Ph. D.)--University of Washington, 1982. / Vita. Bibliography: leaves [312]-339.

Thesis (Honors)--Liberty University Honors Program, 2008. / Includes bibliographical references.

Thesis (Honors)--Liberty University Honors Program, 2008. / Includes bibliographical references.

Thesis (Ph. D., Microbiology, Molecular Biology, and Biochemistry)--University of Idaho, March 2009. / Major professor: Gustavo A. Arrizabalaga. Includes bibliographical references. Also available online (PDF file) by subscription or by purchasing the individual file.

Thesis (doctoral)--University of Helsinki, 2009. / Includes bibliographical references. Also available on the World Wide Web.

Every environment of the biosphere supports a particular mix of microorganisms called a microbiome. These diverse microbial communities play critical roles in the health of ecosystems and in higher organisms, including humans. Disruption or translocation of microbiomes may cause lethal infections, contaminate food and drug supplies, and adversely impact industrial activities. Microbiome detection and molecular characterization have emerged as priorities in many fields. Available methods cannot quickly and efficiently extract rare microorganisms in real specimens. Therefore, microbial detection and analysis require long incubation periods or the use of technically challenging molecular biotechnologies. These strategies are impractical in situations requiring immediate intervention. The intrinsic electric and dielectric properties of microbes permit their isolation by the phenomenon of dielectrophoresis in microfluidic devices. These microsystems have the potential to enhance microbial analysis but are plagued by low processing rates and the inability to interface with biological specimens containing high levels of interfering cells and debris. In this study, a method was created to discriminate between target microbes and undesired cells on the basis of their differential susceptibility to permeabilizing agents that altered cell dielectrophoretic responses. Fabrication techniques were developed to manufacture high-aspect ratio microfluidic channels that allowed the physical forces of gravity, diffusion and dielectrophoresis to be exploited to control cell positions over microscale distances normal to a Poiseuille flow gradient. Because the positioning effects were exploited in only one dimension, the other two dimensions of the channels could be scaled up to create large channel cross-sectional areas that supported rapid specimen processing rates while maintaining high separation efficiencies expected for the microscale effects. These strategies were applied in various ways to isolate microbes from whole blood, platelets, stool, saliva, and skin specimens. The dielectrophoretic extraction of microbes enabled by this approach was used to enable electrical impedance detection of ~100 bacteria in less than five hours. As a result, important technological barriers that have limited the applicability of dielectrophoresis in clinical and industrial settings were overcome by increasing throughput and addressing sample preparation requirements. These proof-of-concept data demonstrate the potential for accelerating microbial isolation and detection in diagnostics, screening, and microbiome research. / text

No description available.

No description available.