S168: Using a novel genome search approach to identify diverse targets relevant to overcoming inhibition associated with microbial biofuel production

Metabolic engineering of desirable characteristics into microorganisms is poised to enter a realm where entire genomes can be created and modified quickly and at a low cost.  For this purpose a vast combinatorial space will have to be explored to identify relevant phenotypes using both rational and evolutionary strategies.  Our lab has developed the Trackable Multiplex Recombineering (TRMR) tool, enabling the rapid mapping of genotypes to phenotypes by using targeted mutations for nearly all genes in the E.coli genome. 

This tool was applied to the general problem of inhibition associated with the production of microbial biofuels.  In particular, here we will present work focused on inhibition associated with product formation (ethanol, isopentenol, fatty acids) as well as with pre-treatment inhibitors (acetate, furfural, total hydrolysate) in Escherichia coli.  Using the identified genetic targets, we were able to increase growth characteristics and tolerance of E.coli to each inhibitor and combine targets to engineer a microorganisms with improved characteristics for biofuel production.