Transport of dicarboxylates by CitP. (A) Effects of C-2 substituents in dicarboxylates on transport via CitP. Citrate consumption by resting cells of L. lactis IL1403(pFL3) is shown in the absence (●) or presence of a 32 mM concentration of the C4-dicarboxylates l-malate (○), oxaloacetate (▼), and succinate (△) (A); 32 mM fumaric acid (▼) and maleic acid (○) (B); and 32 mM oxalic acid (○), malonic acid (▼), glutaric acid (△), and adipic acid (■) (C).