13-36: Production of isobutanol using an immobilized E. coli strain with in situ product removal

E coli JCL16 is an engineered strain for isobutanol production.  The maximal isobutanol yield from sugars was achieved under a micro-aerobic condition.  Isobutanol will be inhibitory for cell growth when the concentration is exceeding 15g/L in the fermentation broth. Previous study has demonstrated that an in-situ product removal by air stripping can efficiently remove isobutanol and improve the productivity, however at a cost of lowering the isobutanol yield [1] .  In this project, we use cell immobilization technology to generate a local micro-aerobic condition to improve the isobutanol yield, within a global aerobic environment generated by air stripping for product removal.  The fermentation conditions, such as air flow rate, pH, mixing intensity, cell immobilization conditions were optimized for improving the isobutanol yield and overall productivity.