关键词: 克雷伯杆菌, 细胞通透性, 非离子表面活性剂, 酶活, 代谢调节

The growth and metabolic reactions were inhibited by product and by-products in Klebsiella pneumoniae fermentation from glycerol to 1,3-propanediol (1,3-PD). The present study was focused on how cellular growth and permeability were enhanced through adding different surfactants in view of 1,3-PD yield. Various treatments with auxiliary agents, such as tween-80, triton X-100, OP-10 and CTAB and their impacts on the activities of glycerol dehydrogenase (GDH), glycerol dehydratase (GDHt) and 1,3-PD oxidoreductase (PDOR) were investigated. It was demonstrated that the performances of OP-10 were dependent on the adding concentration and time, leading to enhancing the growth and permeability of the cell. An adequate amount of OP-10 ensured high activities of GDH and PDOR, and promoted the growth of bacterium. Optimized activity of the cells was manipulated with 1.0 g•L－1 of OP-10 between 8～12 h, associated with the final 1,3-propanediol concentration and molar yield increased greatly. It was also found that when treated with OP-10, the output of nucleic acid increased. From Microscopy image and TEM image of Klebsiella pneumoniae, the reason for the membrane permeability enhancement might be related to the ability of the nonionic surfactant OP-10 to partially damage the membrane structure. It is an effective way to improve enzyme activities, cell growth and 1,3-PD yield with regulation of cellular permeability.

Key words: Klebsiella pneumoniae, cell permeability, nonionic surfactant, enzyme activity, metabolic regulation