Insights into Pathways of Nitrous Oxide Generation from Novel Isotopologue Measurements

Citation

Magyar, Paul Macdonald (2017) Insights into Pathways of Nitrous Oxide Generation from Novel Isotopologue Measurements. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/Z93776RJ. https://resolver.caltech.edu/CaltechTHESIS:05262017-143517395

Abstract

The accumulation of nitrous oxide (N₂O) in the atmosphere is a significant manifestation of human perturbations of the nitrogen cycle. This thesis reports the development and first applications of a novel isotopic technique for characterizing nitrous oxide sources. Chapter 1 describes the development of methods to use the newly available technology of high- resolution dual-inlet multi-collector mass spectrometry to measure six isotopic parameters in nitrous oxide. It reports the standardization and initial biological application of these methods. Chapter 2 presents a model for the generation of isotope effects in an important N₂O generating enzyme, the bacterial nitric oxide reductase; this model and published isotopic constraints are used to provide insights into the mechanism of that enzyme. Chapter 3 describes the six-dimensional isotopic characterization of nitrous oxide from bacterial denitrifiers, while Chapter 4 describes nitrous oxide generated by ammonia oxidizing bacteria.

Thesis Files