Fed-Batch Process for Pyruvate Production by Recombinant Escherichia coli YYC202 Strain

Fed-batch fermentation was applied to the production of pyruvate by using a recombinant Escherichia coli YYC202 strain. This strain is completely blocked in its ability to convert pyruvate into acetyl-CoA or acetate, resulting in acetate auxotrophy during growth in glucose minimal medium. By controlling acetate and glucose feed rate, a series of lab-scale fed-batch experiments were performed at pH 7 and 37 degrees C. CO2 production rate (CTR) was used for on-line regulation of the acetate feed rate. The correlation between CTR and acetate consumption rate (ACR) was determined experimentally. At optimal process conditions a final pyruvate concentration higher than 62 g/L, a space-time yield of up to 42 g/L/d and pyruvate/glucose molar yield of 1.11 mol/mol were achieved. Experimental evidence was gathered that pyruvate export is active.