Date of Award:

5-1-2014

Document Type:

Dissertation

Degree Name:

Doctor of Philosophy (PhD)

Department:

Chemistry and Biochemistry

Advisor/Chair:

Lance C. Seefeldt

Abstract

Population growth over the past ~50 years accompanied by the changes in dietary habits due to economic growth have markedly increased the demand for fixed nitrogen. Aided by biological nitrogen fixation, the Haber-Bosch process has been able to fulfill these demands. However, due to its high temperature and pressure requirements, Haber-Bosch is an expensive process. Every year, approximately 2% of the total energy expenditure by man is used to manufacture fixed nitrogen. Biological systems, on the other hand, produce ammonia at ambient temperature and pressure with much higher efficiency than the Haber-Bosch process. Research in the field of biological nitrogen fixation could prove valuable in understanding the mechanism of the enzyme responsible, nitrogenase. This could eventually allow researchers to mimic the enzyme and fix nitrogen at standard temperature and pressure, which would lead to greater availability of fixed nitrogen and a better standard of living for mankind.

As part of this research, nitrogenase of Azotobacter vinelandii was studied to understand the order of events in reduction of substrates and the conformational changes in the enzyme responsible for its ability to reduce said substrates at room temperature and pressure. This knowledge was used to study variant forms of nitrogenase that could be activated using controlled external reductants. This freedom from the biological reductant of nitrogenase opens the door for further research into the understanding and development of enzyme mimics that can reduce substrates at room temperature and pressure.

Share

COinS