James Swartz, Chemical Engineering and of Bioengineering, Stanford University
The major goal of this exploratory project is to achieve efficient hydrogen production from glucose derived from cellulosic hydrolysates using a cell-free technology based on enzymes made in E. coli. The expression of hydrogen producing enzymes will be induced in densely grown and specially engineered E.coli cells. The unique features that will be engineered into the E.coli will increase hydrogen production yields and rates compared to reported methods. The concentrations of cofactors such as nicotinamide adenine dinucleotide phosphate (NADP) and enzymes of the electron transport chain will be adjusted to direct reactions towards the production of hydrogen. The flow of glucose into the glycolysis breakdown pathway will be blocked using an inhibitor making more of it available for hydrogen production. With these adjustments, this cell-free technology will allow precise control over metabolic fluxes having the potential of reaching a production level of 8 mmoles hydrogen per mole of glucose at a rate of 3 mmoles hydrogen/gram of cells/hour, higher than any system has reportedly achieved to date.
- Kuchenreuther J. M. et al. “High-yield expression of heterologous [FeFe] hydrogenases in Escherichia coli,” PlosOne 5, 11, e15491, doi:10.1371/journal.pone.0015491 (2010).