Abstract:
:A starvation-based dissolved oxygen (DO) transient controller was developed to supply growth-limiting substrate to high cell density fed-batch cultures of recombinant Escherichia coli. The algorithm adjusted a preexisting feed rate in proportion to the culture's oxygen demand, which was estimated from transients in the DO concentration after short periods of feed interruption. In this manner, the addition of glucose feed was precisely controlled at a rate that did not exceed the acetate production threshold, thus preventing acetate accumulation. In comparison to exponential feed algorithms commonly used in industry, the implementation of the new feeding strategy increased the final cell density from 32 to 44 g (dry cell weight).L(-1), with less than 16 mM acetate accumulated, producing an ideal culture for subsequent induction. Despite a constant starvation level and relatively low levels of acetate, experimental cultivations still tended to produce acetate towards the end of the process. The use of a simple Monod model provided an explanation as to why this may occur in high cell density cultivations and suggests how it may be overcome.
journal_name
Biotechnol Bioengjournal_title
Biotechnology and bioengineeringauthors
Whiffin VS,Cooney MJ,Cord-Ruwisch Rdoi
10.1002/bit.10802subject
Has Abstractpub_date
2004-02-20 00:00:00pages
422-33issue
4eissn
0006-3592issn
1097-0290journal_volume
85pub_type
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