关键词: 克雷伯氏菌, 诱变, 3-丙二醇, 发酵, 动力学

Abstract: The strain of Klebseilla pneumoniae was exposed under dielectric barrier discharge plasma at air atmospheric pressure. The physical parameters of plasma discharge and optimum conditions of mutagenesis were established. The exposed cell suspension was acclimatized repeatedly under different concentrations of substrate and product, respectively, and single colony was selected by 96-hole plate. A mutant with improved 1,3-propanediol (1,3-PD) production was obtained and designated as Kp-M2. Compared with wild type, the 1,3-PD concentration was increased by 43% in batch fermentation. The kinetic models of Kp-M2 and wild type in batch fermentation were proposed based on the Logistic and Luedeking-Piret equations of cell growth, product formation and substrate consumption. The maximum specific growth rate, formation coefficient of 1,3-PD coupling cell growth and yield coefficient of 1,3-PD on glycerol in Kp-M2 were significantly higher than those of wild type.

Key words: Klebsiellla pneumoniae, mutagenesis, 3-propanediol, fermentation, kinetics