The invention relates to an isolated polynucleotide containing a polynucleotide sequence selected from the group comprising a) polynucleotide which is at least 70% identical to a polynucleotide which codes for a polypeptide containing the amino acid sequence of SEQ ID no. 2, b) polynucleotide which codes for a polypeptide containing an amino acid sequence which is at least 70% identical to the amino acid sequence of SEQ ID no.2, c) polynucleotide which is complementary to the polynucleotides of a) or b), and d) polynucleotide containing at least 15 successive nucleotides of the polynucleotide sequence of a), b) or c), and a process for the fermentative production of L-amino acids with enhancement of the ptsH gene coding for component H of the phosphotransferase system, and the use of the above polynucleotides as primer or hybridisation probe.