The goal of our project was to develop Bacillus megaterium as a host for continuous biofuel production coupled with in situ product extraction by supercritical (sc) CO2 stripping. We aimed to develop a system that utilizes supercritical CO2 (scCO2) to address challenges associated with microbial contamination, product toxicity, and product recovery that currently limit the potential of advanced biofuel and bio-based chemical production. We proposed an interdisciplinary research and development effort involving bioprocess engineering, systems biology, and chemical separation engineering, centered around a recently isolated microorganism that is tolerant to scCO2. To this end we pursued a series of Aims and Sub-Aims with the ultimate goals of 1) determining the systems physiology of B. megaterium during growth under scCO2 (Aim 1)
2) engineering heterologous butanol production pathways for anaerobic and aerobic expression in B. megaterium (Aims 1 & 2)
3) conducting de novo pathway engineering for biosynthesis of longer chain fuels (Aim 2)
and 4) developing and modeling a two-phase stripping chemostat for continuous production of biofuels with in situ scCO2 extraction (Aim 3).