Back to Search Start Over

Analysis of metabolic flux in Escherichia coli expressing human-like collagen in fed-batch culture.

Authors :
Luo, Yan E.
Fan, Dai D.
Shang, Long A.
Shi, Hui J.
Ma, Xiao X.
Yu Mi
Zhao, Gui F.
Source :
Biotechnology Letters; Apr2008, Vol. 30 Issue 4, p637-643, 7p, 1 Diagram, 3 Charts, 1 Graph
Publication Year :
2008

Abstract

Metabolic flux distributions of recombinant Escherichia coli BL21 expressing human-like collagen were determined by means of a stoichiometric network and metabolic balancing. At the batch growth stage, the fluxes of the pentose phosphate pathway were higher than the fluxes of the fed-batch growth phase and the production stage. After the temperature was increased, there was a substantially elevated energy demand for synthesizing human-like collagen and heat-shock proteins, which resulted in changes in metabolic fluxes. The activities of the Embden-Meyerhof-Parnas pathway and the tricarboxylic acid cycle were significantly enhanced, leading to a reduction in the fluxes of the pentose phosphate pathway and other anabolic pathways. The temperature upshift also caused an increase in NADPH production by isocitrate dehydrogenase in the tricarboxylic acid cycle. The metabolic model predicted the involvement of a transhydrogenase that generates additional NADH from NADPH, thereby increasing ATP regeneration in the respiratory chain. These data indicated that the maintenance energy for cellular activity increased with the increase in biomass in fed-batch culture, and that cell growth and synthesis of human-like collagen could clearly represent the changes in metabolic fluxes. At the production stage, more NADPH was used to synthesize human-like collagen than for maintaining cellular activity, cell growth, and cell propagation. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
01415492
Volume :
30
Issue :
4
Database :
Complementary Index
Journal :
Biotechnology Letters
Publication Type :
Academic Journal
Accession number :
29994060
Full Text :
https://doi.org/10.1007/s10529-007-9593-1