Escherichia coli responds with a rapid and large change in growth rate upon a shift from glucose-limited to glucose-excess conditions
Metabolic Engineering, cilt.13, sa.3, ss.307-318, 2011 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 13 Sayı: 3
- Basım Tarihi: 2011
- Doi Numarası: 10.1016/j.ymben.2011.03.003
- Dergi Adı: Metabolic Engineering
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
- Sayfa Sayıları: ss.307-318
- Anahtar Kelimeler: Amino acid metabolism, Central metabolism, In vivo kinetics, Intracellular metabolites-fluxes, Stimulus response experiments
- Boğaziçi Üniversitesi Adresli: Hayır
Özet
Glucose pulse experiments at seconds time scale resolution were performed in aerobic glucose-limited Escherichia coli chemostat cultures. The dynamic responses of oxygen-uptake and growth rate at seconds time scale were determined using a new method based on the dynamic liquid-phase mass balance for oxygen and the pseudo-steady-state ATP balance. Significant fold changes in metabolites (10-1/10) and fluxes (4-1/4) were observed during the short (200. s) period of glucose excess. During glucose excess there was no secretion of by-products and the increased glucose uptake rate led within 40. s to a 3.7 fold increase in growth rate. Also within 40-60. s a new pseudo-steady-state was reached for both metabolite levels and fluxes. Flux changes of reactions were strongly correlated to the concentrations of involved compounds. Surprisingly the 3.7 fold increase in growth rate and hence protein synthesis rate was not matched by a significant increase in amino acid concentrations. This poses interesting questions for the kinetic factors, which drive protein synthesis by ribosomes. © 2011 Elsevier Inc.