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Methane metabolism and nitrogen cycling in freshwater sediment of a polluted ecosystem : Hamilton Harbour (Canada)

Environmental regulation of nitrogen cycling processes, denitrification and nitrification, was studied in sediment of Hamilton Harbour, with particular emphasis on the role of CH$ sb4$ metabolism (production and consumption). Through extensive sediment sampling and numerical analysis, it was found that particulate carbon was the best predictor of potential for anaerobic production of CH$ sb4$ and CO$ sb2$. The only predictor of denitrification capacity was anaerobic CO$ sb2$ production, indicating that beside NO$ sb3 sp-$ and O$ sb2$, a biotic factor involved in carbon metabolism may be important in the control of this activity. / Suppression of aerobic N$ sb2$O production in sediment slurries by C$ rm sb2H sb2$ and correlation with NO$ sb3$-production indicated that it was dependent on chemolithotrophic nitrification. Although CH$ sb4$ (1 to 24 $ mu$M) stimulated production of NO$ sb3 sp-$ and N$ sb2$O, we found that CH$ sb4$ at 84 $ mu$M or greater suppressed nitrification. Following extensive studies of pore water chemistry, potential microbial activities, and counts of nitrifiers and methanotrophs, we found that CH$ sb4$ oxidation (i) is more likely to suppress nitrification by competition for O$ sb2$ and NH$ sb4 sp+$ between methanotrophs and nitrifiers, and (ii) may be more important than nitrification as a sink of hypolimnetic O$ sb2$ in Hamilton Harbour. / Amongst a number of inhibitors, allylsulfide was found to be a differential inhibitor with much less effect on CH$ sb4$ oxidation in sediment slurries or in axenic cultures of Methylosinus trichosporium OB3b than on nitrification in sediment slurries.

Identiferoai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.39990
Date January 1995
CreatorsRoy, Réal, 1963-
ContributorsKnowles, Roger (advisor)
PublisherMcGill University
Source SetsLibrary and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada
LanguageEnglish
Detected LanguageEnglish
TypeElectronic Thesis or Dissertation
Formatapplication/pdf
CoverageDoctor of Philosophy (Department of Natural Resource Sciences.)
RightsAll items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated.
Relationalephsysno: 001488795, proquestno: NN12470, Theses scanned by UMI/ProQuest.

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