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IPTG limitation avoids metabolic burden and acetic acid accumulation in induced fed-batch cultures of Escherichia coli M15 under glucose limiting conditions

Paper ID Volume ID Publish Year Pages File Format Full-Text
3445 171 2013 6 PDF Available
Title
IPTG limitation avoids metabolic burden and acetic acid accumulation in induced fed-batch cultures of Escherichia coli M15 under glucose limiting conditions
Abstract

The most common strategy to produce recombinant proteins using Escherichia coli as expression vector is fed-batch culture, since high cell density cultures strategies have successfully been applied. Several methodologies to limit the specific growth rate in order to control E. coli metabolism have been defined, demonstrating that cultures can be grown under glucose limitation up to high cell densities without accumulation of acetic acid. However, under induction conditions it has been observed that E. coli metabolism is reorganized again and leads to acetic acid accumulation, causing inhibition of cell growth and decreasing protein expression efficiency.We propose a double limitation strategy (glucose and IPTG) for E. coli fed-batch cultures to avoid the deregulation of the metabolism in the induction phase. Reducing the concentration of IPTG while keeping glucose growth limitation, the accumulation of acetic acid decreased. At an IPTG concentration of 0.03 mmol/g DCW no accumulation of acetic acid was observed during the induction phase, in contraposition to what has normally been observed.Although a slight reduction of protein expression rate was observed when applying this double limitation strategy, the bioprocess volumetric productivity was enhanced due to the capability to prolong the induction phase, reaching higher levels of protein production. Another advantage of this strategy is the reduction of media cost due to the lower level of IPTG used.

► We described a more robust and productive high cell density cultures of E. coli. ► Double limitation of glucose and IPTG during induction phase avoids metabolic burden and acetic acid accumulation. ► Induction phase of high cell density cultures can be extended. ► Higher cell densities of induced cultures, specific product concentration, and thus volumetric productivity can be achieved. ► Novel production strategies in E. coli can be performed.

Keywords
Fed-batch culture; Escherichia coli; Bioprocess design; Substrate limitation; IPTG limitation; Acetic acid accumulation
First Page Preview
IPTG limitation avoids metabolic burden and acetic acid accumulation in induced fed-batch cultures of Escherichia coli M15 under glucose limiting conditions
Publisher
Database: Elsevier - ScienceDirect
Journal: Biochemical Engineering Journal - Volume 70, 15 January 2013, Pages 78–83
Authors
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Subjects
Physical Sciences and Engineering Chemical Engineering Bioengineering