Improving green hydrogen production with biologically delivered L-cysteine

To stem climate change, energy uses must be de-carbonized. However, renewable energies (eg. wind, solar) will not completely fulfill the need. Additional renewables are needed. One such renewable is green hydrogen, which is produced by the dark fermentation (DF) of organic waste. Adoption of this technology however has been slow due to low hydrogen yields. Yields can be improved ~60% by introducing L-cysteine into the DF process flow, though excessive cysteine kills the bacteria that drive DF. To optimize cysteine levels, undergraduates are designing, building, and testing a tunable bacterium that produces L-cysteine up to the maximum tolerated dose.

Image