Process for preparing L-amino acids using improved strains of the Enterobacteriaceae family

摘要

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, andb) 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 ≧0 to 100%) in the isolated product or being removed completely.

主权项

1. A process for preparing a desired L-amino acid by fermenting a recombinant microorganism of the Enterobacteriaceae family, which comprises:
a) culturing the recombinant microorganism, which has been genetically modified to overexpress a polynucleotide encoding a polypeptide having acetate permease activity and an amino acid sequence that is at least 95% identical to SEQ ID NO: 2, in a fermentation medium under conditions under which the desired L-amino acid accumulates in the fermentation medium or in the recombinant microorganism, wherein the copy number of the polynucleotide encoding the polypeptide having acetate permease activity has been increased by at least 1 and/or a strong promoter is operably linked to the polynucleotide encoding the polypeptide having acetate permease activity; and b) concentrating the fermentation medium prior to recovery of the desired L-amino acid.