Kinetic, biochemical, and genetic analysis of the particulate methane monooxygenase

Author: Semrau, Jeremy D.

Year: 1995

Degree: Dissertation (Ph.D.)

Advisors: Lidstrom, Mary E.; Chan, Sunney I.

Committee Member: Unknown, Unknown

Option: Environmental Science and Engineering

DOI: 10.7907/jvdy-gy47

Abstract

The partiuculate methane monooxygenase (pMMO) is expressed by all known methanotrophs and may be very useful for the degradation of small halogenated hydrocarbons such as trichloroethylene (TCE). The pMMO, however, is poorly understood and much work is needed to determine the usefulness of this enzyme for the degradation of wastes both in-situ and in above-ground treatment reactors. In this thesis, the kinetics, biochemistry, and genetics of the pMMO are examined. The research indicates that copper plays a major role in the kinetics of both TCE and methane oxidation by the pMMO. Furthermore, by correlating activity assays, metal analysis, and electron paramagnetic resonance spectroscopy, we have concluded that copper makes up the active site of the pMMO, and that multiple active sites may exist on the pMMO. Finally, genetic analysis of chromosomal DNA from several methanotrophs indicates that two copies of the pMMO exist. Data suggest the products of these gene copies may be different, and that they might be affected by the amount of bioavailable copper.

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