Enhancing Ethanol Production with RNA-Engineering of Zymomonas Mobilis

A key challenge facing the biofuel industry is the antimicrobial nature of ethanol and other pretreatment chemicals to the microbes that catalyze the conversion of biomass to ethanol. Zymomonas mobilis has been recognized as a useful bacterium for this catalysis because it naturally produces and tolerates ethanol in high quantities. Small regulatory RNAs (sRNAs) in Z. mobilis that change expression under ethanol stress indicate the possibility to engineer increased ethanol production and tolerance. In this study, we evaluate which sRNAs most positively affect ethanol production by overexpression or deletion from the genome. This way, we can engineer a more robust strain of Z. mobilis that is apt for ethanol production by combining different overexpressions and deletions of these RNA regulators. In doing so, we serve the biofuel production community seeking to develop the most efficient microorganisms to enable chemical production in a cost-effective and sustainable way. By increasing ethanol yields directly and allowing bacteria to live longer in their own product, we demonstrate that multiple sRNAs can be manipulated to enhance ethanol tolerance and ultimately that sRNAs are powerful tools for metabolic engineering in this organism.