Theses and Dissertations at Montana State University (MSU)
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Item The optimal consortia of microbial bioremediation agents for the removal of heavy metals from the superfund site at newtown creek in brooklyn, new york(Montana State University, 2020) Korecki, Danielle Angela; Chairperson, Graduate Committee: Amaya Garcia-CostasBioremediation is a technique that introduces a microbial population capable of destroying, transforming, or immobilizing a pollutant of interest in a manner that is both safe to the environment and cost-effective. Bioremediation agents are effective in sequestering heavy metals, and are capable of functioning at their highest capacity when environmental conditions are complimentary to microbial growth, the indigenous microbial population favorably interacts with the introduced microorganisms, and nutritional requirements are satisfied either by the ecosystem or via the addition of amendments. Additionally, genetically engineered microorganisms can be utilized when necessary within especially challenging conditions. This study determines the ability of a consortia of microbial bioremediation agents to remove heavy metals from the Superfund site at Newtown Creek in Brooklyn, New York. The remediation of heavy metals at Newtown Creek can be accomplished using Rhodopseudomonas palustris, Saccharomyces cerevisiae, and Cupriavidus metallidurans. These microorganisms possess a high degree of potential and are promising tools in the reduction of Earth's ever-increasing pollution levels. Heavy metal concentrations, nutrient levels, pH, temperature, salinity, oxidation reduction potential, and the indigenous microbiome were analyzed to determine the expected benefit of microbial bioremediation in the reduction of heavy metal concentrations. Although high initial heavy metal concentrations and salinity may negatively impact this effort, all other variables are expected to be conducive to microbial growth. The introduction of amendments is expected to further benefit microbial bioremediation potential. The selected consortia of microorganisms introduced have the capacity to sequester all the chromium, lead, mercury, selenium, and silver found at Newtown Creek. The impact of arsenic, cadmium, copper, nickel, and zinc concentrations can also be decreased due to microbial bioremediation efforts. The use of genetically engineered microorganisms within a bioreactor is expected to further benefit remediation efforts for heavy metals sequestered at low rates within the natural environment. Microbial bioremediation is not expected to fully remove heavy metals from Newtown Creek, yet these microorganisms are capable of greatly improving conditions.Item The interaction of heavy metals with the mammalian gut microbiome(Montana State University - Bozeman, College of Agriculture, 2022) Coe, Genevieve Lea; Chairperson, Graduate Committee: Seth Walk; This is a manuscript style paper that includes co-authored chapters.Heavy metals are for the most part, naturally occurring elements found in the environment. Some are essential, meaning they are involved in critical biochemical pathways, in all branches of life. Other heavy metals are non-essential and disrupt metabolic functions in most organisms rendering them toxic. The following research explored the interactions of the mammalian gut microbiome with an essential heavy metal, iron, and a non-essential heavy metal, methylmercury, acquired through the diet. The overarching goal was to define and characterize the influence of gut microbial interactions with heavy metals on host health. Novel experimental designs using murine models were designed to examine 1) the consequences of low iron challenge on the murine gut microbiome and whether host iron availability was affected and 2) the potential influence of the gut microbiome in methylmercury elimination rate and demethylation in conventional, germ-free, gnotobiotic, and humanized mice. Culturing in vitro and toxicity assays, 16S sequencing, deep metagenomic sequencing of human stool, bioinformatic analysis, transcriptional analysis of iron biomarkers, quantification of iron and mercury by ICP-MS and HPLC-ICP-MS methods were performed as well as the use of mouse models to examine iron and methylmercury interactions with the gut microbiome in vivo. Our results from this project indicate that the gut microbiome is significantly affected by loss of iron from the diet, and does not fully recover post-iron repletion, while the host is relatively unaffected by low-iron challenge to the gut microbiome. Methylmercury elimination and demethylation is significantly faster and higher, respectively, in mice with a gut microbiome, providing novel evidence in support of a role for the gut microbiome in methylmercury demethylation and elimination. However, exact mechanisms of microbial interactions with methylmercury in the gut have yet to be elucidated. Our data also suggests the possibility of host-mediated mechanisms of methylmercury demethylation, by yet unknown mechanisms that warrant further exploration.Item The effects of metals on trout populations in the Upper Boulder River, Montana(Montana State University - Bozeman, College of Letters & Science, 1976) Nelson, Frederick A.Item The effects of heavy metals on the distribution and abundance of aquatic insects in the Boulder River, Montana(Montana State University - Bozeman, College of Letters & Science, 1977) Gardner, William M.Item Metal accumulation in voles from an acid mine drainage impacted wetland(Montana State University - Bozeman, College of Agriculture, 1990) Zavitz, Thomas LindseyItem Transport and activity of dissimilatory metal-reducing bacteria in porous media for the remediation of heavy metals and chlorinated hydrocarbons(Montana State University - Bozeman, College of Engineering, 2001) Gerlach, RobinItem Clean tailing reclamation : revegetation of mill tailings following removal of pyrite and heavy metals(Montana State University - Bozeman, College of Agriculture, 1997) Krueger, Jane MarieItem Recovery of copper by biopolymer gel and polymer vegetation by electrowinning and ion exchange technologies(Montana State University - Bozeman, College of Engineering, 1995) Kallepalli, Ramakrishna RajuBiopolymer gel beads of calcium alginate and alginic acid have high affinities for divalent metal ions such as Cu 2+. Hence they may be useful materials for recovering copper from aqueous solutions. The copper sorbed by the calcium alginate gel beads could be completely eluted and the metal recovered in a salable metallic form by using a combination of ion-exchange and electrowinning technologies. In such processes, the calcium alginate gel beads are fully regenerated. The resorption capacity of the gel beads did not decrease significantly during up to three sorption-desorption-electrowinning cycles. Distribution ratios of copper between the gel and liquid phases were measured using a batch method. Distribution ratios of copper for gel beads of calcium alginate ranged from 0.3 to 0.9 liter solution/gram dry sodium alginate [(mg Cu 2+ / gram dry sodium alginate)/(mg Cu 2+ / liter solution)]. Distribution ratios of copper for gel beads of alginic acid ranged from 0.47 to 0.84 liter solution/gram dry sodium alginate [(mg Cu 2+ / gram dry sodium alginate)/(mg Cu 2+ / liter solution)]. The equilibrium data were consistent with the ion-exchange reaction between cupric ions and calcium alginate/alginic acid. Maximum sorption capacities of the gel beads of calcium alginate and alginic acid were determined by comparing the experimental data with theoretical predictions. Maximum sorption capacities of the gel beads were found to be 5.21 X 10 -3 kmol/ kg dry sodium alginate and 4.11 X 10 -3 kmol/ kg dry sodium alginate for calcium alginate and alginic acid respectively. 3.2% sodium alginate in water was used to make the gel beads of calcium alginate and alginic acid. Scale up of the technology was studied in a fluidized bed reactor and electrowinning cell designed for this purpose. Calcium alginate gel beads were reused up to three times for absorption of copper after regeneration using ion exchange and electrowinning technologies. This technology reduced the influent copper concentration by 63%.Item The relationship of selected plants and their vesicular-arbuscular mycorrhizae in a heavy metal environment(Montana State University - Bozeman, College of Agriculture, 1985) Ferns, Thomas WilliamItem The impacts of trace metals on grass communities along the floodplains of Soda Butte Creek, Montana and Wyoming(Montana State University - Bozeman, College of Letters & Science, 1995) Stoughton, Julie Ann