C. glutamicum strains express modified gluconate repressor proteins GntR1 and GntR2. The C. glutamicum strains have an increased ability to produce L-lysine compared with an ability of a wildtype strain. The gluconate repressor protein GntR1 includes an amino acid sequence of SEQ ID NO: 9, where the amino acid Arg in position 102 is replaced by the amino acid Glu. The gluconate repressor protein GntR2 includes SEQ ID NO: 10, and its activity is attenuated compared to the activity of the GntR2 repressor protein of the wild-type strain. A method is developed for the fermentative production of L-lysine using such C. glutamicum strains.