ISSN:
0006-3592
Keywords:
carbon starvation
;
Escherichia coli
;
growth control
;
Chemistry
;
Biochemistry and Biotechnology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
,
Process Engineering, Biotechnology, Nutrition Technology
Notes:
The use of glucose starvation to uncouple the production of recombinant β-galactosidase from cell growth in Escherichia coli was investigated. A lacZ operon fusion to the carbon starvation-inducible cst-1 locus was used to control β-galactosidase synthesis. β-Galactosidase induction was observed only under aerobic starvation conditions, and its expression continued for 6 h following the onset of glucose starvation. The cessation of β-galactosidase expression closely correlated with the exhaustion of acetate, an overflow metabolite of glucose, from the culture medium. Our results suggest the primary role of acetate in cst-1-controlled protein expression is that of an energy source. Using this information, we metered acetate to a glucose-starved culture and produced a metabolically sluggish state, where growth was limited to a low linear rate and production of recombiant β-galactosidase occurred continuously throughout the experiment. The cst-1 controlled β-galactosidase synthesis was also induced at low dilution rates in a glucose-limited chemostat, suggesting possible applications to high-density cell systems such as glucose-limited recycle reactors. This work demonstrates that by using an appropriate promoter system and nutrient limitation, growth can be restrained while recombinant protein production is induced and maintained.
Additional Material:
5 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/bit.260400211
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