Production of L-phenylalanine from phenylpyruvate using resting cells of Escherichia coli

The authors describe the production of L-phenylalanine from phenylpyruvate using resting cells of a genetically modified strain of Escherichia coli . Fermentations were carried out by continuously raising the feeding rate of D-glucose. The cells reached a biomass of 10 g/l dry weight and an aminotransferase activity of 14000 U/l. The maximum phenylalanine concentration achieved was 173 mmol/l with a phenylpyruvate molar conversion yield of 95%.