Effect of iclR and arcA deletions on physiology and metabolic fluxes in Escherichia coli BL21 (DE3).
Deletion of both iclR and arcA in E. coli profoundly alters the central metabolic fluxes and decreases acetate excretion by 70%. In this study we investigate the metabolic consequences of both deletions in E. coli BL21 (DE3). No significant differences in biomass yields, acetate yields, CO(2) yields and metabolic fluxes could be observed between the wild type strain E. coli BL21 (DE3) and the double-knockout strain E. coli BL21 (DE3) ΔarcAΔiclR. This proves that arcA and iclR are poorly active in the BL21 wild type strain. Noteworthy, both strains co-assimilate glucose and acetate at high glucose concentrations (10-15 g l(-1)), while this was never observed in K12 strains. This implies that catabolite repression is less intense in BL21 strains compared to in E. coli K12.
Centre of Expertise-Industrial Biotechnology and Biocatalysis, Department of Biochemical and Microbial Technology, Ghent University, Coupure Links 653, 9000, Ghent, Belgium. Hendrik.Waegeman@UGent.be
Hendrik
H
Waegeman
Jo
J
Maertens
Joeri
J
Beauprez
Marjan
M
De Mey
Wim
W
Soetaert
D000085:Acetates / Q000378:metabolism; D001425:Bacterial Outer Membrane Proteins; D018533:Biomass; D002245:Carbon Dioxide / Q000378:metabolism; D048168:Escherichia coli K12 / Q000235:genetics / Q000254:growth & development / Q000378:metabolism / Q000502:physiology*; D029968:Escherichia coli Proteins; D017353:Gene Deletion; D005947:Glucose / Q000378:metabolism; D012097:Repressor Proteins / Q000172:deficiency*
D000085:Acetates; D001425:Bacterial Outer Membrane Proteins; D029968:Escherichia coli Proteins; D012097:Repressor Proteins; C041610:arcA protein, E coli; C067479:IclR protein, E coli; D002245:Carbon Dioxide; D005947:Glucose