Cover photograph (Copyright © 2008, American Society for Microbiology. All Rights Reserved.): Research wines stored in the cellar of the Department of Viticulture and Enology at University of California, Davis. The malolactic, or secondary, fermentation of wine is often carried out by Oenococcus oeni, an ethanol- and acid-tolerant lactic acid bacterium. (Photograph courtesy of Greg Hirson.) (See related article on page 564.)