Our Projects

Ammonia Oxidizers & Greenhouse Gases

Specialized groups of bacteria and archaea make a living by oxidizing ammonia to nitrite as their sole energy-generating metabolism. Due to alarming increases in the greenhouse gas, nitrous oxide, to the atmosphere, there has been intensive interest in understanding how these chemolithotrophic microorganisms contribute to the nitrogen cycle and nitrous oxide release. We are using cutting-edge technologies of microrespirometry and RNAseq to show that ammonia-oxidizing bacteria and archaea have distinct mechanisms for metabolizing nitrogen and releasing nitrogen oxides. The metabolic intermediate, nitric oxide, plays a critical (albeit different) role in the pathways of both bacteria and archaea, although only the bacteria have enzymology to convert nitric oxide to nitrous oxide. This very exciting and novel line of research is changing the way we understand the microbial nitrogen cycle and makes use of one of the largest collections of genome-sequenced ammonia-oxidizing isolates in the world. Projects in the lab involve collaboration with many distinguished colleagues around the world.

Industrialization of Microorganisms Using Single-carbon Feedstocks

Bioengineering methanotrophic bacteria to create valuable and safe products from hazardous waste. The resurgent interest in synthetic biology and green chemistry has placed methane-consuming microorganisms at the forefront of new bioindustrial developments. Using the genome sequenced culture collection of methanotrophic bacteria, we are working with Dr. Dominic Sauvageau in Chemical and Materials Engineering and industrial partners to screen for value-added products created by bacteria as they consume methane, methanol and carbon dioxide. Projects in this area include screening the metabolites of methanotrophic bacteria for value-added products, optimization of growth and product formation, and metabolic pathway engineering.