Dielectric barrier discharge plasma as a novel approach for improving 1,3-propanediol production in Klebsiella pneumoniae

Abstract

Dielectric barrier discharge plasma was used to generate a stable strain of Klebsiella pneumoniae (designated to as Kp-M2) with improved 1,3-propanediol production. The specific activities of glycerol dehydrogenase, glycerol dehydatase and 1,3-propanediol oxidoreductase in the crude cell extract increased from 0.11, 9.2 and 0.15 U mg⁻¹, respectively, for wild type to 0.67, 14.4 and 1.6 U mg⁻¹ for Kp-M2. The glycerol flux of Kp-M2 was redistributed with the flux to the reductive pathway being increased by 20% in batch fermentation. The final 1,3-propanediol concentrations achieved by Kp-M2 in batch and fed-batch fermentations were 19.9 and 76.7 g l⁻¹, respectively, which were higher than those of wild type (16.2 and 49.2 g l⁻¹). The results suggested that dielectric barrier discharge plasma could be used as an effective approach to improve 1,3-propanediol production in K. pneumoniae.