Time profiles of metabolites in the glucose-supplemented culture. Three bacterial strains, N16961, O395, and SSY01, were grown in LB containing 1% glucose for 8 h. Levels of glucose, acetoin, lactic acid, and acetic acid in culture supernatants were measured as described in Materials and Methods and plotted with respect to time. In panel B, lines for O395 and SSY01 are superimposed.