Engineering Microbial Efflux Pumps for Biofuel Secretion

Engineering Microbial Efflux Pumps for Biofuel Secretion

The microbial conversion of sugars to biofuels is a promising new technology, but the byproducts of pretreatment processes and the fuels themselves are often toxic to the production host at industrially-relevant levels.  A promising solution to this problem is to evolve a genetically tractable organism for fuel tolerance.  Some mechanisms that are known to contribute to tolerance are less desirable (e.g. conversion of the fuel product to a non-toxic chemical) than others.  One particular tolerance mechanism would be particularly advantageous:  Altering the pumps that microbes use to secrete antibiotics and other toxic chemicals out of the cell to instead secrete the fuel product.  Understanding the natural diversity of such pumps and how to modify them for the efflux of desired chemicals will be critical for successful microbial biofuel production.  We will present results describing the characterization and genetic optimization of protein-based efflux pumps for the secretion of byproducts of pretreatment processes and biofuels from gram-negative bacteria.