Biological systems are not typically under selective pressure to optimally and maximally produce an overabundance of highly-reduced products such as advanced biofuels. Generating organisms with these energy-relevant characteristics requires biotechnological manipulation guided by a strong fundamental understanding of key electron flow mechanisms. The Harwood laboratory is part of a DOE Energy Frontier Research Project on Biological Electron Transfer and Catlaysis (BETcY). We wish to determine how the photosynthetic bacterium Rhodopseudomonas palustris can use variant forms of nitrogenase enzymes as a biocatalyst for production of energy-rich hydrocarbons from carbon dioxide. This will require that we understand how cells control and divert electron flux and ATP production to nitrogenase.