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›› 2007, Vol. 7 ›› Issue (5): 1014-1017.

• 生化工程专栏 • 上一篇    下一篇

利用氧化还原电位调控基因工程菌株Klebsiella pneumoniae F-1合成1,3-丙二醇

黄志华,张延平,杜晨宇,黄星,曹竹安   

  1. 三明学院化学与生物工程系
  • 出版日期:2007-10-20 发布日期:2007-10-20

Improvement of 1,3-Propanediol Production with a Recombinant Strain Klebsiella pneumoniae F-1 by Regulating Redox Potential

HUANG Zhi-hua,ZHANG Yan-ping,DU Chen-yu,HUANG Xing,CAO Zhu-an   

  1. Department of Chemistry and Biology Engineering, Sanming College
  • Online:2007-10-20 Published:2007-10-20

摘要: 基因工程菌株Klebsiella pneumoniae厌氧发酵过程中,氧化还原电位(ORP)是一个监控发酵过程的重要指标. 考察了K. pneumoniae F-1在不同ORP(-190, -210, -240和-290 mV)下菌体生长和代谢产物合成的情况. 在ORP为-240 mV时,1,3-丙二醇的发酵终浓度和得率分别为81.5 g/L和0.423 mol/mol,分别为4种ORP条件下的最高值. 这说明ORP=-240 mV是菌株K. pneumoniae F-1的最适ORP. 此ORP既不同于野生菌株K. pneumoniae M5aL的最适ORP(-190 mV),也不同于经过诱变的菌株K. pneumoniae YMU2的最适ORP(-280 mV). 另外,通过研究发酵体系ORP对甘油代谢流的影响,发现还原性氛围较有利于甘油向1,3-PD、乙醇、2,3-丁二醇等还原性较高的代谢物转化. 首次报道了ORP调控发酵过程在基因工程改造菌株中的应用,这对于进一步研究ORP调控厌氧发酵过程具有一定的意义.

关键词: 3-丙二醇, NADH再生, 氧化还原电位, Klebsiella pneumoniae

Abstract: Redox potential (also called oxidoreduction potential, ORP) is one of important indicators to monitor the anaerobic fermentation of Klebsiella pneumoniae. In this report, the preferred ORP of a recombinant strain K. pneumoniae F-1 was investigated by controlling the ORP of broth into four levels of -190, -210, -240 and -290 mV. The results showed that in the fermentation of ORP at -240 mV, the highest final 1,3-propanediol concentration and molar yield of were achieved, being 81.5 g/L and 0.423 mol/mol, respectively. This preferred ORP to the genetic modified strain was different from those of both the wild strain K. pneumoniae M5aL (-190 mV) and the mutant K. pneumoniae M5aL YMU2 (-280 mV). It is demonstrated that the modification of the metabolic pathway in the K. pneumoniae F-1 exerted effects on the preferred ORP of the strain. The effect of ORP on re-distribution of the metabolites was also investigated. The results demonstrated that the reduction environment facilitated the pathways from glycerol to reduction end-metabolites, such as 1,3-propanediol, ethanol and 2,3-butanediol. This work is the first investigation on the ORP regulation method in a recombinant strain, which will provide insight into the mechanism of ORP regulation in anaerobic fermentations.

Key words: 3-propanediol, cofactor (NADH) regeneration, redox potential, Klebsiella pneumoniae