earticle

영어

Klebsiella oxytoca stains are excellent 2,3-butanediol producers. To use this strain in industry area, 2,3-butanediol must be produced more than now. In order to achieve a high production, the budC gene of acetoin reductase was overexpressed by inserting the budC gene, which is ligated to puc18K with a kanamycin resistance, into K. oxytoca KTCC 1685 and K. oxytoca ATCC 43863. Byproducts like lactic acid, acetoin, acetic acid and ethanol reduce the amounts of 2,3-butanediol. Among of them, lactic acid especially affects the fermentation efficiency for 2,3-butanediol production. Two K. oxytoca mutants deficient in lactic acid formation were successfully constructed by knocking out the ldhA gene coding for lactate dehydrogenase of them. After fermentation studies of mutant stains, the result showed that 2,3-butanediol production was enhanced compared with the wild type strains.