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Tracking the acetate threshold using DO‐transient control during medium and high cell density cultivation of recombinant Escherichia coli in complex media
Author(s) -
Johnston Wayne A.,
Stewart Meredith,
Lee Peter,
Cooney Michael J.
Publication year - 2003
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.10772
Subject(s) - transient (computer programming) , fed batch culture , oxidizing agent , recombinant dna , chemistry , biochemistry , gene , computer science , organic chemistry , fermentation , operating system
DO‐transient nutrient controllers use the dissolved oxygen signal to attempt acetate threshold tracking during fed‐batch cultivation of recombinant E. coli . Here we apply DO‐transient control to the production of Jembrana disease virus protein in complex Super Luria medium and compare performance against a high‐limit pH‐stat controller. For induction at medium cell density (harvest between 31 and 32.5 g dcw L) a total productivity of 0.27 g L h was achieved as compared to 0.24 g L h with the high‐limit pH‐stat. For induction at high cell density (harvest at 60 g dcw L), decreased productivity (0.12 g L h) was attributed to the effect of acetate accumulation on recombinant protein formation and a concomitant lowering of the critical growth rate. Our results suggest that complex media provides a difficult environment for the application of acetate threshold tracking DO‐transient control because of difficulties in re‐oxidizing acetate, and apparent localized production of acetate below the production threshold (as detected by the DO‐transient controller as SPOUR crit ). Configuring the DO‐transient controller to avoid aggressive threshold probing is suggested as a means to improve performance and reduce acetate accumulation in complex media. © 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 84: 314–323, 2003.