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Physiologic mechanisms of sequential products synthesis in 1,3‐propanediol fed‐batch fermentation by Klebsiella pneumoniae
Author(s) -
Zheng ZongMing,
Xu YunZhen,
Liu HongJuan,
Guo NiNi,
Cai ZhongZhen,
Liu DeHua
Publication year - 2008
Publication title -
biotechnology and bioengineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.136
H-Index - 189
eISSN - 1097-0290
pISSN - 0006-3592
DOI - 10.1002/bit.21830
Subject(s) - glycerol , fermentation , klebsiella pneumoniae , exponential growth , 1,3 propanediol , chemistry , ethanol , biochemistry , escherichia coli , mathematical analysis , mathematics , gene
The glycerol fed‐batch fermentation by Klebsiella pneumoniae CGMCC 1.6366 exhibited the sequential synthesis of products, including acetate, 1,3‐propanediol (1,3‐PD), 2,3‐butanediol, ethanol, succinate, and lactate. The dominant flux distribution was shifted from acetate formation to 1,3‐PD formation in early‐ exponential growth phase and then to lactate synthesis in late‐exponential growth phase. The underlying physiological mechanism of the above observations has been investigated via the related enzymes, nucleotide, and intermediary metabolites analysis. The carbon flow shift is dictated by the intrinsic physiological state and enzymatic activity regulation. Especially, the internal redox state could serve as a rate‐controlling factor for 1,3‐PD production. The q 1,3‐PD formation was the combined outcomes of regulations of glycerol dehydratase activity and internal redox balancing. The q ethanol / q acetate ratios demonstrated the flexible adaptation mechanism of K. pneumoniae preferring ATP generation in early‐exponential growth phase. A low PEP to pyruvate ratio corresponded LDH activity increase, leading to lactate accumulation in stationary phase. Biotechnol. Bioeng. 2008;100: 923–932. © 2008 Wiley Periodicals, Inc.