(626e) Engineering a Thioesterase for Improved Medium-Chain Fatty Acid Profile

Chemicals carrying a linear medium-chain (C8-C12) hydrocarbon have uses as fuels, and commodity and fine chemicals. Medium-chain chemicals are derived from medium-chain fatty acids (MCFAs) via derivatization with tailoring enzymes. Microbial production of MCFAs is hindered by the inefficient heterologous expression of medium-chain plant thioesterases and the broad fatty acid profile of bacterial thioesterases. Here, we use rational protein design to engineer a bacterial thioesterase for improved MCFA production in Escherichia coli. Further, using a previously developed G-protein coupled receptor (GPCR)-based MCFA sensor, we detect the different MCFA levels of produced by E. coli expressing the wild type and engineered thioesterases. This work sets the stage for sensor-guided engineering of MCFA producing microbes.