Process for the production of L-lysine

An isolated mutant coryneform bacterium comprising a DNA fragment with promoter activity operably linked to a polynucleotide coding for a protein with dihydrodipicolinate reductase activity, wherein said DNA fragment comprises the sequence of SEQ ID NO:12 but with one or more substitutions selected from the group consisting of:

• a) substitution of the nucleobase thymine at position 36 of SEQ ID NO:12 by guanine;
• b) substitution of the nucleobase cytosine at position 37 of SEQ ID NO:12 by guanine;
• c) substitution of the nucleobase guanine at position 40 of SEQ ID NO:12 by thymine;
• d) substitution of the nucleobase cytosine at position 42 of SEQ ID NO:12 by adenine;
• and wherein:
• i) relative to a bacterial parent strain which does not carry said DNA fragment operably linked to a polynucleotide coding for a protein with dihydrodipicolinate reductase activity, said mutant coryneform bacterium produces more L-lysine when fermented in nutrient medium and under conditions suitable for lysine production;
• and
• ii) relative to a DNA fragment of SEQ ID NO:12 without any of said substitutions, said DNA fragment with the sequence of SEQ ID NO:12 with one or more of said substitutions has increased transcriptional activity.