Regulation of vitamin c and vitamin e on the biosynthesis of 1,3-propanediol by klebsiella pneumoniae

Glycerol could be transformed to 1,3-propanediol (1,3-PD) by Klebsiella pneumoniae. Since NADH was required in the process, reductants were considered to affect the formation of 1,3-propanediol. In this work, 40-150 mg/L VC or 20-100 mg/L VE was added into the culture medium to regulate the intracellular redox state (NADH/NAD) of Klebsiella pneumoniae, and the effects of these two reductants on the metabolism of Klebsiella pneumoniae were investigated. It was shown that the concentration of 1,3-propanediol increased by 20%-30% by addition of 150 mg/L VC or 30 mg/L VE into the culture medium. With the increasing 1,3-PD, some byproducts such as ethanol and 2,3-butanediol increased correspondingly, which resulted in an inconspicuous improvement of the yield of 1,3-PD. Rather than addition of these reductants, regulation of metabolic flux was considered to be a feasible attempt to improve the yield of 1,3-PD.