Effect of iclR and arcA deletions on physiology and metabolic fluxes in Escherichia coli BL21 (DE3)

• Published in: Biotechnology letters Vol. 34; no. 2; pp. 329 - 337
• Main Authors: Waegeman, Hendrik, Maertens, Jo, Beauprez, Joeri, De Mey, Marjan, Soetaert, Wim
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer-Verlag 01.02.2012; Springer Netherlands; Springer; Springer Nature B.V
• Subjects: Acetates; Acetates - metabolism; Applied Microbiology; Bacterial Outer Membrane Proteins; Bacterial proteins; Biochemistry; Biological and medical sciences; Biomass; Biomedical and Life Sciences; Biotechnology; Carbon dioxide; Carbon Dioxide - metabolism; Deletion; E coli; Escherichia coli; Escherichia coli K12 - genetics; Escherichia coli K12 - growth & development; Escherichia coli K12 - metabolism; Escherichia coli K12 - physiology; Escherichia coli Proteins; excretion; Fluxes; Fundamental and applied biological sciences. Psychology; Gene Deletion; Glucose; Glucose - metabolism; Life Sciences; Metabolism; Microbiology; Original Research Paper; Repressor Proteins - deficiency; Strain; ArcA; Recombinant protein production; IclR; Acetate; BL21; Escherichia coli; Metabolism; Production; Deletion; Bacteria; Physiology; Recombinant protein; Enterobacteriaceae
• ISSN: 0141-5492; 1573-6776
• DOI: 10.1007/s10529-011-0774-6

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, CO2 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.