Plasmids carrying the pyc gene from Rhizobium etli were used to express pyruvate carboxylase in Escherichia coli. Results of batch fermentations of a wild-type E. coli (MG1655), this wild-type with the pUC18 cloning/expression vector (MG1655/pUC18) and this wild-type carrying the pyc gene (MG1655/pUC18-pyc) were compared in glucose-limited medium. The results indicate that the final succinate concentration upon complete glucose utilization was increased from 1.18 g/L to 1.77 g/L by the expression of pyc, while the final succinate concentration in MG1655/pUC18 was slightly lower than in the parent strain. This increased succinate concentration came at the expense of lactate synthesis, whose final concentration decreased from 2.33 g/L to 1.88 g/L. The expression of pyc did not affect the maximum glucose uptake (2.17 g/L.h for MG1655 versus 2.47 g/L.h for MG1655/pUC18-pyc), but did decrease the maximum rate of cell mass production (0.213 g/L.h for MG1655, 0.169 g/L.h for MG1655/pUC18 and 0.199 g/L.h for MG1655/pUC18-pyc).