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Item An omics-based interrogation of disparate microbial systems: multi-omics analysis of a bio-mining archaeon and the effects of arsenic on the E. coli Lipidome(Montana State University - Bozeman, College of Letters & Science, 2023) Fausset, Hunter Lee; Chairperson, Graduate Committee: Brian Bothner; This is a manuscript style paper that includes co-authored chapters.Systems biology represents the next frontier in the elucidation of biochemical mechanisms, disease states, and microorganisms. Rather than approaching individual parts of an organism, such as a specific protein, molecule, or mRNA, a systems biology or "omics" investigation seeks to characterize all proteins, molecules, or RNA simultaneously. This is crucial, because all macromolecules in a lifeform exist in dynamic equilibria with those around them; no one biological process occurs in a vacuum. Omics investigations have ballooned in usage over the last decades due to scientists realizing their power in characterizing complex biological phenomena. This has also been spurred on by advances in technologies enabling the robust elucidation of thousands of molecules at once, particularly benefitting from the modernization of mass spectrometry. This technique can be used to study any number of biological problems including those presented here; a multi-omics investigation into a mineral- eating methanogen and a lipidomic characterization of arsenic exposure in a key member of the gut microbiome, E.coli. Methanosarcina barkeri, a widespread methanogen found in marine sediments, is able to reductively dissolve minerals such as pyrite (FeS2) to satisfy their iron and sulfur requirements. Presented here are two investigations containing transcriptomic, proteomic, metabolomic, and lipidomic analyses, performed in parallel on the same biomass. Together, these experiments suggest that the organism undergoes a significant phenotypic shift in response to changes in just two elements, Fe and S. Overall inferences are echoed in the small molecule analyses; the metabolomes and lipidome of the organism change similarly in to the proteome. Key sulfur equilibria are implied in the process, as are specific lipids, choline, and dethiobiotin. A similar approach was applied to E.coli treated with arsenic, as a proxy for understanding the detoxifcation that takes place in the gut microbiome after ingestion. Marked lipidomic changes were observed in E.coli resulting from treatment, which were dependent both on species of arsenic as well as presence of the Ars operon. As a foundational study, this work answered some and generated many more hypotheses on the biochemical fate of As in microorganisms in the gut microbiome.Item Chemical approaches to probe environmental stress in Archaea(Montana State University - Bozeman, College of Letters & Science, 2009) Tarlykov, Pavel Victorovich; Chairperson, Graduate Committee: Brian BothnerLittle is known about strategies and mechanisms employed by thermophilic organisms to adapt to environmental stress. Sulfolobus solfataricus is a thermophile that belongs to Archaea, the third domain of life, and can be found in unusual habitats, such as the hot springs of Yellowstone National Park. This archaeon can tolerate high temperature, extreme acidity and high concentrations of heavy metals and other toxic substances. Thus, S. solfataricus has been chosen by many researchers as a model system for biochemical, structural, and genetic studies. In this work S. solfataricus has been exposed to hydrogen peroxide as a natural mild oxidant and arsenic as a common toxic metalloid. One of the aims was to quantitatively define the regulation of proteins upon treatment with hydrogen peroxide or arsenic species in different time periods and concentrations. In this sense, two-dimensional gel electrophoresis approach in conjunction with novel chemical tagging probes has been applied to detect changes on the level of regulation and chemical modification of individual proteins within the whole proteome in response to the stressors. Proteins expression levels have been monitored, redox-sensitive and phosphoproteomic profiles of the S. solfataricus proteome have been identified. Synthesis of the results has allowed a general scheme for how S. solfataricus fights H₂O₂- and As-induced stress. Lists of mapped proteins have been created and potential biomarkers for oxidative stress have been identified, which can guide further research to better understand mechanisms of proteomic response to the environmental stress in Archaea on the example of thermophilic archaeon S. solfataricus.