能量驱动对Klebsiella pneumoniae发酵甘油合成1,3-丙二醇的影响

考察了外加能量对Klebsiella pneumoniae合成1,3 丙二醇的影响，结果表明，外加0.6 0.8 g/L三磷酸腺苷 ATP 可以有效促进Klebsiella pneumoniae发酵甘油的还原代谢，1,3 丙二醇产量提高了50 70 ，得率在发酵后期仍能维持在较高水平. 利用休止细胞研究了甘油脱水酶催化失活后能量刺激复活的情况，结果表明外加三磷酸腺苷(ATP)对休止细胞中甘油脱水酶的复活有明显的驱动作用，经多次失活/驱动复活后甘油脱水酶活性可维持不变.

Effect of ATP Addition on 1,3-Propanediol Biosynthesis from Glycerol by Klebsiella pneumoniae

Biosynthesis of 1,3-propanediol (1,3-PD) attracted much attention recently. Glycerol dehydratase, the key enzyme of the biosynthesis of 1,3-PD from glycerol, tends to undergo mechanism-based inactivation by glycerol during catalysis, and the inactive dehydratase was rapidly reactivated in the presence of AdoCbl, ATP and Mg2+ (or Mn2+). In this paper, the effect of ATP on biosynthesis of 1,3-PD from glycerol by Klebsiella pneumoniae L1 was investigated. Although bacterium growth was inhibited with ATP addition in fermentation medium, the capability of 1,3-PD biosynthesis by K. pneumoniae cells per OD was increased. By addition of 0.6~0.8 g/L ATP, the reductive metabolism of glycerol was strengthened and the titer of 1,3-propanediol increased by 50%~70%. The yield of 1,3-PD was also improved, especially in the latter phase of fermentation compared with a rapidly decreased yield in control experiment. For seeing about the simulative effect of ATP on 1,3-PD biosynthesis, rest K. pneumoniae cells were used in this work. It indicated that ATP could reactivate the inactive glycerol dehydratase effectively, and the activity of dehydratase would not decrease observably during repetitious reactivation. ATP was an important factor affecting the catalysis activity of glycerol dehydratase and even the biosynthesis of 1,3-PD from glycerol by K. pneumoniae. Keeping ATP in a higher concentration in the fermentation system was a logical approach to improve 1,3-PD biosynthesis.