抄録
The pyruvic acid productivities of thiamine or lipoic acid auxotrophs derived from α-ketoglutaric acid-producing Enterobacter aerogenes SM-18 were determined using a washed cell reaction system. As a result, mutants showing high pyruvic acid productivities were more frequently found among lipoic acid auxotrophs, and one of them, strain L-12, was selected as the best producer. When this strain was shake-cultured in a medium containing 2 % glucose for 3 days, both pyruvic and α-ketoglutaric acids were produced in amounts of 4.7 and 1.6 g/1, respectively, with the limited lipoic acid concentration of 0.5μg/l, whereas only α-ketoglutaric acid was accumulated, in a yield of 5.5 g/1, with the sufficient vitamin concentration of 50 μg/1. The pyruvic acid production was confirmed to be due to a decrease in the activity of the pyruvate dehydrogenase complex caused by the lipoic acid deficiency.
