Increasing Isoprenol Production in Engineered E. coli through Medium Optimization and Different Fermentation Strategies.

Due to the increasing demand for bio-aviation fuel, different strategies have been developed for its production. One promising bio-aviation fuel is monoterpenes, which have similar characters with current aviation fuels. Monoterpenes can be synthesized from a precursor: isoprenol (isopentenol,3-methyl-3-buten-1-ol). Previous study expressed the mevalonate pathway with a novel IPP-bypass (AtoB, HMGS, HMGR, MK, PMD) in E. coli DH1 for isoprenol production. This strain can obtain over 60-70% theoretical yield of isoprenol from glucose. In this study, the minimal medium for this engineered E. coli strain was further optimized to increase isoprenol titer. Different combinations of carbon sources and nitrogen sources with various concentrations were tested to obtain the optimal C/N ratio in the medium. Different fermentation strategies were also developed to further increase isoprenol titer, such as fed-batch fermentation and in-situ solvent recovery.