Pyruvic acid production by an F1-ATPase-defective mutant of Escherichia coli W1485lip2.

An F1-ATPase-defective mutant, TBLA-1, was constructed by the transduction of a defective gene for the alpha subunit of F1-ATPase, atpA401, into Escherichia coli W1485lip2, a lipoic acid-requiring pyruvic acid producer. The pyruvic acid production of the strain TBLA-1 was found to be improved markedly compared with that of strain W1485lip2. In cultures using a jar fermentor, the strain W1485lip2 consumed 50 g/liter of glucose and produced 25 g/liter of pyruvic acid after culture for 32h, while strain TBLA-1 consumed the same amount of glucose, and produced more than 30 g/liter of pyruvic acid in a 24-h culture. A revertant, No. 63-1, derived from the strain TBLA-1, had a normal level of F1-ATPase activity, and showed a similar pattern of pyruvic acid production to that of strain W1485lip2.