The invention relates to a process for preparing L-amino acids by fermenting recombinant microorganisms of the Enterobacteriaceae family, characterized in that a) the desired L-amino acid-producing microorganisms, in which the yjcG-ORF, or nucleotide sequences or alleles encoding the gene product, is/are enhanced, in particular overexpressed, is cultured in a medium under conditions under which the desired L-amino acid is accumulated in the medium or in the cells, and b) the desired L-amino acid is isolated, with, where appropriate, constituents of the fermentation broth, and/or the biomass remaining in its/their entirety or in portions (from .gtoreq.0 to 100%) in the isolated product or being removed completely.