Restoration's return in the age of climate crisis: toward a feminist environmental justice response

University of Minnesota Ph.D. dissertation. November 2014. Major: Feminist Studies. Advisor: Dr. Jacquelyn Zita. 1 computer file (PDF); iv, 158 pages.This project is situated at the locus of discourses on feminism, environmental justice, climate change, and ecological restoration. Asking what kinds of responses to climate change are needed on this rapidly-changing planet, and which initiatives will address social and ecological dilemmas simultaneously, I turn to ecological restoration as a troubled but promising field to harness the insights of feminist environmental justice toward intervening in both the causes and consequences of climate change. In order to engender resiliency among human and nonhuman communities, I advocate a contextualized, grassroots response to climate change that I have coined justice-oriented restoration. This ideology and method strengthens voices and movements often marginalized by engaging diverse stakeholders in order to create ecologies responsive to climatically-induced biosocial shifts, as well as the declining field of restoration itself, which climate change threatens to render irrelevant. In so doing, this project contributes to debates on sustainability; to the cross-pollination of the humanities, social sciences, and sciences; and to the momentum building worldwide for community-driven, site-specific adaptations, mitigations, and remediations to environmental vulnerabilities

Microbial penetration through Berea sandstone and the effect of nitrate on biogenic sulfide production :

Results from energy dispersion spectroscopy, and electron microscopy of autoclaved and dry-heat sterilized rock revealed that changes in mineral content and clay morphology of autoclaved rock could account for faster penetration of bacteria through autoclaved versus dry-heat sterilized rock. However, changes in permeability, porosity, and pore throat size of rock sterilized by the two methods were not sufficient to account for differences in penetration times.The addition of 58.8 mM nitrate was found to inhibit biogenic sulfide production in sewage sludge (10% v/v) amended with 20 mM sulfate and either acetate, glucose, or hydrogen as energy sources. This inhibition was observed for at least six months and was accompanied by the oxidation of the redox indicator, resazurin, from its colorless reduced state to its pink oxidized state. Lesser amounts of nitrate (5.9 mM and 19.5 mM), as well as, increasing amounts of sewage sludge resulted in only transient inhibition of sulfide production. The addition of 156 mM sulfate and 58.8 mM nitrate to 10% sewage sludge or pond sediment slurries resulted in no sulfide inhibition. The prolonged inhibition of sulfide production was attributed to an increase in oxidation-reduction potential due to production of biogenic nitrous oxide. These oxidized conditions appeared to have a cytotoxic affect on sulfate-reducing populations.Penetration times, and penetration rates, for a motile Bacillus strain growing in nutrient-saturated Berea sandstone cores were determined. The rate of penetration was essentially independent of permeability above 100 mD and rapidly declined for permeabilities below 100 mD. It was found that these penetration rates could be grouped into two statistically distinct classes consisting of rates for permeabilities above 100 mD and those below 100 mD. The maximum observed penetration rate was 0.47 cm h('-1) and the slowest was 0.06 cm h('-1). The motile Enterobacter aerrogenes penetrated Berea sandstone cores 3-8 times faster than the non-motile Klebsiella pneumoniae strain when cores of comparable length of permeability were used. A penetration mechanism based entirely on motility predicted penetration times that were in agreement with the observed penetration times for motile strains

Electrokinetic-enhanced removal of toluene from physically heterogeneous granular porous media

Electrokinetics (EK) was applied to enhance biodegradation of toluene in a low hydraulic conductivity (K) zone of a physically heterogeneous water-saturated granular porous media. The hypothesis tested was that EK transport processes, which operate independently of advection, can deliver a limiting amendment, nitrate, across a high- /lowK boundary to stimulate bioremediation. Two types of experiment were evaluated: (1) bench-scale tests that represented the active EK system and physically heterogeneous sediment configuration; and (2) microcosms that represented biodegradation in the bench-scale tests under ideal conditions. The bench-scale experiment results showed a rapid decrease in toluene concentration during the application of EK that was attributed to electroosmotic removal from low-K zones. Comparison of toluene removal rates by electroosmosis and biodegradation (microcosm) confirmed that electroosmosis was the most effective mechanism under the conditions evaluated. Overall, this work challenged the original hypothesis and indicates that, at the field scale, the most favourable conditions for biodegradation are likely to be achieved by applying EK to increase contaminant flux across the low-/high- K boundary (out of the low-K zone) and allowing biodegradation to occur in the high-K zone either by natural attenuation or enhanced by amendment addition

Growth of Leuconostoc mesenteroides NRRL-B523 in an alkaline medium: Suboptimal pH growth inhibition of a lactic acid bacterium

Bacterial profile modification (BPM), a form of tertiary oil recovery, diverts water from the water-flooded high-permeability zone into the oil-bearing low-permeability zone. During field use, exopolymer-producing bacteria plug the high-permeability zone only in the immediate vicinity of the injection point (the near-well bore region). For effective BPM the plug must penetrate far into the formation. Slowing the specific growth rate, lengthening the lag phase, and slowing the polymerization rate are techniques that can prolong the onset of biopolymer gelation and extend the depth of the biological plug. In batch experiments, the growth of Leuconostoc mesenteroides NRRL-B523 was inhibited by the synergistic effects of high substrate loading and an alkaline pH. Exponential growth was delayed up to 190 h. It was observed that cell division was significantly retarded until the medium pH, reduced by the acid byproducts of fermentation, reached a critical value of 6.79 ± 0.06. A mathematical model was developed to describe the relationship between specific growth rate, lag time, and medium pH. © 2004 Wiley Periodicals, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/34343/1/20315_ftp.pd

Impact of elevated nitrate on sulfate-reducing bacteria: A comparative study of Desulfovibrio vulgaris

Sulfate-reducing bacteria have been extensively studied for their potential in heavy-metal bioremediation. However, the occurrence of elevated nitrate in contaminated environments has been shown to inhibit sulfate reduction activity. Although the inhibition has been suggested to result from the competition with nitrate-reducing bacteria, the possibility of direct inhibition of sulfate reducers by elevated nitrate needs to be explored. Using Desulfovibrio vulgaris as a model sulfate-reducing bacterium, functional genomics analysis reveals that osmotic stress contributed to growth inhibition by nitrate as shown by the upregulation of the glycine/betaine transporter genes and the relief of nitrate inhibition by osmoprotectants. The observation that significant growth inhibition was effected by 70 mM NaNO{sub 3} but not by 70 mM NaCl suggests the presence of inhibitory mechanisms in addition to osmotic stress. The differential expression of genes characteristic of nitrite stress responses, such as the hybrid cluster protein gene, under nitrate stress condition further indicates that nitrate stress response by D. vulgaris was linked to components of both osmotic and nitrite stress responses. The involvement of the oxidative stress response pathway, however, might be the result of a more general stress response. Given the low similarities between the response profiles to nitrate and other stresses, less-defined stress response pathways could also be important in nitrate stress, which might involve the shift in energy metabolism. The involvement of nitrite stress response upon exposure to nitrate may provide detoxification mechanisms for nitrite, which is inhibitory to sulfate-reducing bacteria, produced by microbial nitrate reduction as a metabolic intermediate and may enhance the survival of sulfate-reducing bacteria in environments with elevated nitrate level

Microbial Penetration through Nutrient-Saturated Berea Sandstone

Penetration times and penetration rates for a motile Bacillus strain growing in nutrient-saturated Berea sandstone cores were determined. The rate of penetration was essentially independent of permeabilities above 100 mdarcys and rapidly declined for permeabilities below 100 mdarcys. It was found that these penetration rates could be grouped into two statistically distinct classes consisting of rates for permeabilities above 100 mdarcys and rates for those below 100 mdarcys. Instantaneous penetration rates were found to be zero order with respect to core length for cores with permeabilities above 100 mdarcys and first order with respect to core length for cores with permeabilities below 100 mdarcys. The maximum observed penetration rate was 0.47 cm · h(−1), and the slowest was 0.06 cm · h(−1); however, these rates may be underestimates of the true penetration rate, since the observed rates included the time required for growth in the flask as well as the core. The relationship of penetration time to the square of the length of the core suggested that cells penetrated high-permeability cores as a band and low-permeability cores in a diffuse fashion. The motile Enterobacter aerogenes strain penetrated Berea sandstone cores three to eight times faster than did the nonmotile Klebsiella pneumoniae strain when cores of comparable length and permeability were used. A penetration mechanism based entirely on motility predicted penetration times that were in agreement with the observed penetration times for motile strains. The fact that nonmotile strains penetrated the cores suggested that filamentous or unrestricted growth, or both, may also be important