Zymomonas mobilis is one of the most promising microorganisms for bioethanol production. However, its practical use on industrial scale is impeded by its high sensitivity to acetate, which is present in high concentration in pretreated biomass. This research develops an adaptive mutation method for generating acetate-tolerant strains for bioethanol production. The goal is to obtain Zymomonas mobilis strain capable of growing and producing ethanol in the presence of acetate at a concentration typical of a pretreated biomass (2-3%). The interplay between the ability of fermentative production of ethanol and acetate tolerance will be investigated through careful fermentation studies. The potential cross-tolerance to other inhibitors, commonly present in pretreated biomass will be evaluated. A preliminary study on the mechanism of acetate tolerance at the cell membrane level will be conducted. The strain developed through this research will be useful in bioethanol production from biomass. The insights into tolerance mechanisms gained through this study will allow a more rational approach to further engineer a better producing strain.