Metabolic Engineering Group
Microbes, such as E. coli and yeast, have been used for the production of valuable chemicals (i.e., fuels, medicines, base chemicals) that the microbes do not normally generate in nature. To achieve this "microbial chemical factory," we introduce a biosynthetic pathway from one organism into another host organism (this process is referred to as a "heterologous expression") and engineer the metabolic pathway using genetic manipulation to optimize the production of target chemicals.
At JBEI's Fuels Synthesis Division, we have studied several potential biofuel candidates (i.e., fatty acid esters, alcohols, isoprenoids), have verified their fuel properties, and have demonstrated production from our engineered host. The Metabolic Engineering Group is responsible for conducting research to further refine both the engineering of the host's metabolic pathway and the biosynthetic pathways introduced from another organism, in order to improve production yield. For example, one class of our target fuels is the isoprenoid compound. The biosynthetic pathway for isoprenoid biofuels in E. coli uses a heterologously expressed mevalonate pathway (a part of that pathway is displayed below).
From acetyl-CoA (a common building block in most biosynthetic pathways) to isopentenyl diphosphate (a building block for isoprenoid compounds), the biosynthetic pathway needs six enzymatic steps (shown in red above). These enzymatic steps use different cofactors (i.e., NADPH and NADP), enzyme activity and specificity are all different, and portions of the pathway are often toxic to the host organism. We search for the best enzymes for each enzymatic step in order to find the optimal condition and combination for biofuel production. By using synthetic biology tools, advanced Omics, and analytical tools, we study how to control the expression of these enzymes to find the best combination to optimize biofuel production.
The Metabolic Engineering Group at JBEI's Fuels Synthesis Division collaborates with other groups in the Division and with other Divisions at JBEI to advance biomass-to-biofuel conversion. We also collaborate with other institutes (i.e., UC Berkeley, National Renewable Energy Laboratory, Combustion Research Facility at Sandia National Laboratory, Southwest Research Institute) to evaluate the fuel value of our biofuels.
