An engineered bacterium for producing ethanol from one or more carbohydrates is disclosed. The bacterium can be made by (a) inactivating within a Lactobacillus casei bacterium one or more endogenous genes encoding a lactate dehydrogenase; or (b) introducing into a Lactobacillus casei bacterium one or more exogenous genes encoding a pyruvate decarboxylase and one or more exogenous genes encoding an alcohol dehydrogenase II; or (c) performing both steps (a) and (b). The resulting engineered bacterium produces significantly more ethanol than the wild-type Lactobacillus casei bacterium, and can be used in producing ethanol from a substrate such as biomass that includes carbohydrates.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
 This invention was made with government support under DE-FC02-07ER64494 awarded by the US Department of Energy and 2011-67009-30043 awarded by the USDA/NIFA. The government has certain rights in the invention.