Open Access. Powered by Scholars. Published by Universities.®

Environmental Microbiology and Microbial Ecology Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 4 of 4

Full-Text Articles in Environmental Microbiology and Microbial Ecology

Nutritional Regulation Of Sulfonamide Antibiotic Biodegradation By Microbacterium Sp. Strain C448, Tonya Malcolm Dec 2017

Nutritional Regulation Of Sulfonamide Antibiotic Biodegradation By Microbacterium Sp. Strain C448, Tonya Malcolm

Electronic Thesis and Dissertation Repository

Sulfonamide antibiotics are frequently released into the environment due to their widespread use in livestock production, imposing a potential selection pressure for the development and dissemination of sulfonamide resistance. Recently, a sulfonamide-degrading bacterium Microbacterium sp. Strain C448 was discovered, whose activity has the potential to be used as a sulfonamide removal strategy from agricultural soils. This research gains insight into the sulfonamide biodegradation pathway by 1) evaluating the nutritional regulation of sulfamethazine biodegradation and 2) undertaking a comparative proteomic analysis of cells grown in the presence and in the absence of sulfamethazine. The nutritional analyses revealed that increasing amounts of …


Urea As An Effective Nitrogen Source For Cyanobacteria, Kevin J. Erratt Oct 2017

Urea As An Effective Nitrogen Source For Cyanobacteria, Kevin J. Erratt

Electronic Thesis and Dissertation Repository

Urea use has grown substantially in the past half-century, with urea now accounting for > 50% of nitrogen fertilizer applications worldwide. The shift from inorganic nitrogen fertilizers to urea-based sources has coincided with the reappearance of cyanobacteria blooms in freshwaters. Here, we examined urea as a nitrogen source for three bloom-forming cyanobacteria species. We found that (1) urea was consumed more rapidly relative to inorganic nitrogen substrates, suggesting that cyanobacteria exhibit a preference for urea; (2) urea was consumed in excess of cellular requirements; and (3) urea may offer cyanobacteria a competitive edge over eukaryotic algae by enhancing light absorption capabilities. …


Disturbance And The Community Composition Of Arbuscular Mycorrhizal Fungi In Ontario Tallgrass Prairies, Sarah N. Allan Jul 2017

Disturbance And The Community Composition Of Arbuscular Mycorrhizal Fungi In Ontario Tallgrass Prairies, Sarah N. Allan

Electronic Thesis and Dissertation Repository

Arbuscular mycorrhizal fungi (Glomeromycota) form beneficial symbiotic relationships with the majority of land plants, especially in grasslands. Tallgrass prairies in Ontario are an endangered plant community currently being restored on former agricultural land. The objectives of my study were to determine if there were differences in the communities of Glomeromycota between disturbed and undisturbed tallgrass prairies in Ontario and if there were any potential indicator taxa for the ends of the disturbance spectrum. A molecular approach using DNA derived from soil samples was used to compare species composition between disturbed and undisturbed tallgrass prairies. A total of 177 operational taxonomic …


Microbial Repopulation Following In Situ Star Remediation, Gavin Overbeeke Feb 2017

Microbial Repopulation Following In Situ Star Remediation, Gavin Overbeeke

Electronic Thesis and Dissertation Repository

In situ STAR (Self-sustaining Treatment for Active Remediation) is an emerging remediation technology which uses smouldering combustion to destroy nonaqueous phase liquid (NAPL) contamination in the subsurface. Since STAR smouldering travels through contaminated soils slowly (~0.5 to 5 m/day) and subjects them to high temperatures (400–1000°C), it is expected that this technology will thoroughly dry and sterilize the zones which it treats. Further, soils surrounding the treatment zone which are not smouldered will be heated, although not smouldered, by virtue of their proximity to STAR, impacting microbial communities within them. Therefore, the objectives of this work are to quantify the …