Creation of green knallgas bacteria to produce renewable plastics

Large scale biofermentation with CO2 and electrically generated H2 as feedstocks is currently being explored as an attractive method for production of renewable alternatives to petrochemicals.

The microorganism used in these processes are anaerobic or require elevated CO2 for fast growth, making them a poor choice for de novo CO2 fixation from the atmosphere.

However, the fast-growing cyanobacteria Synechococcus PCC 11901 grows at high rates in ambient CO2 levels due to a highly efficient carbon fixation system.

Therefore, Synechococcus could be an interesting unexplored candidate for lithotrophic bioproduction, if it could grow on H2.In this project, a H2-consuming Synechococcus strain will be created.

An oxygen tolerant hydrogenase will be engineered in and the strain will be adapted for growth on H2 using laboratory evolution. Mutations causing adaptation to this new form of growth will be used to explore photosynthetic regulation.

The ability to produce the plastic precursor ethylene will be engineered into the strain to explore its use as a platform strain while comparing production and growth to phototrophic conditions as well as a native lithotrophic strain.

As such, this project will attempt to create an industrially relevant strain to be used for efficient bioproduction directly from atmospheric levels of CO2.