Many bacteria can utilize C 4 -carboxylates as carbon and energy sources. However, Corynebacterium glutamicum ATCC 13032 is not able to use tricarboxylic acid cycle intermediates such as succinate, fumarate, and L-malate as sole carbon sources. Upon prolonged incubation, spontaneous mutants which had gained the ability to grow on succinate, fumarate, and L-malate could be isolated. DNA microarray analysis showed higher mRNA levels of cg0277, which subsequently was named dccT, in the mutants than in the wild type, and transcriptional fusion analysis revealed that a point mutation in the promoter region of dccT was responsible for increased expression. The overexpression of dccT was sufficient to enable the C. glutamicum wild type to grow on succinate, fumarate, and L-malate as the sole carbon sources. Biochemical analyses revealed that DccT, which is a member of the divalent anion/Na ؉ symporter family, catalyzes the effective uptake of dicarboxylates like succinate, fumarate, L-malate, and likely also oxaloacetate in a sodium-dependent manner.Corynebacterium glutamicum is a predominantly aerobic nonsporulating and biotin-auxotrophic gram-positive bacterium which is used for the industrial production of amino acids, mainly of L-lysine (Ͼ750,000 tons/year) (61) and glutamate (Ͼ1,500,000 tons/year) (50). C. glutamicum is well studied not only with respect to amino acid biosynthesis but also regarding carbon metabolism and its regulation (2, 6, 57). C. glutamicum grows aerobically on a variety of carbohydrates and organic acids as the sole sources of carbon and energy, e.g., on sugars like glucose, fructose, and sucrose and on organic acids like gluconate, acetate, propionate, pyruvate, and L-lactate, but also on ethanol, glutamate, vanillate, 4-hydroxybenzoate, and protocatechuate (1, 7-9, 19, 31, 35, 59). In general, growth on substrate mixtures is characterized by coutilization, e.g., of glucose with acetate (59), and even a nongrowth substrate like serine can be utilized simultaneously with glucose (35). Rarely, preferential utilization of glucose before glutamate or ethanol, e.g., has been observed (1, 28).Citrate is the only tricarboxylic acid (TCA) cycle intermediate described as supporting the growth of C. glutamicum (42). C. glutamicum can grow on citrate as the sole carbon source and coutilizes citrate and glucose (42). In a combined DNA microarray and proteome analysis, it was revealed that the expression of genes for two citrate uptake systems, CitM and TctABC, was induced when citrate was present in the medium (42). Although succinate uptake by C. glutamicum has been observed in biochemical assays, growth on succinate has not been reported (11,41). Other bacteria, e.g., Bacillus subtilis, are able to grow not only with citrate but also with the dicarboxylic TCA cycle intermediates succinate, fumarate, and Lmalate (55). The transporter YdbH in B. subtilis is responsible for the uptake of fumarate and succinate (3) but not for that of L-malate, which is taken up via MaeN (52) or the malate/ lactate antipo...