Chromosome Engineering To Generate Plasmid-Free Phenylalanine- and Tyrosine-Overproducing Strains That Can Be Applied in the Generation of Aromatic-Compound-Producing Bacteria.

Many phenylalanine- and tyrosine-producing strains have used plasmid-based overexpression of pathway genes. The resulting strains achieved high titers and yields of phenylalanine and tyrosine. Chromosomally engineered, plasmid-free producers have shown lower titers and yields than plasmid-based strains, but the former are advantageous in terms of cultivation cost and public health/environmental risk.

Escherichia coli chromosome-based T7-dependent constitutive overexpression system and its application to generating a phenylalanine producing strain.

Many metabolic engineering approaches have been attempted to generate strains capable of producing valuable compounds. One of main goals is industrial application of these strains. Integration of synthetic pathway genes into the Escherichia coli chromosome enables generation of a plasmid-free strain that is stable and useful for industrial applications.