title: Segregation to non-dividing cells in recombinant Escherichia coli fed-batch fermentation processes.
abstract: In Escherichia coli fermentation processes, a drastic drop in viable cell count as measured by the number of colony forming units per ml (c.f.u. ml(-1)) is often observed. This phenomenon was investigated in a process for the production of the recombinant fusion protein, promegapoietin (PMP). After induction, the number of c.f.u. ml(-1) dropped to approximately 10% of its maximum though the biomass concentration continued to increase. Flow cytometric analysis of viability and intracellular concentration of PMP showed that almost all cells were alive and contributed to the production. Thus, the drop in the number of c.f.u. ml(-1) probably reflects a loss of cell division capability rather than cell death.
authors.affiliation: Department of Biotechnology, Royal Institute of Technology, Roslagstullsbacken 21, S-10691 Stockholm, Sweden.
authors.forename: Heléne
authors.initials: H
authors.lastname: Sundström
authors.forename: Fredrik
authors.initials: F
authors.lastname: Wållberg
authors.forename: Erika
authors.initials: E
authors.lastname: Ledung
authors.forename: Bo
authors.initials: B
authors.lastname: Norrman
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Hewitt
authors.forename: Sven-Olof
authors.initials: SO
authors.lastname: Enfors
mesh_terms: D017209:Apoptosis / Q000502:physiology; D019149:Bioreactors / Q000382:microbiology; D002449:Cell Aggregation / Q000502:physiology; D002470:Cell Survival / Q000502:physiology; D015169:Colony Count, Microbial / Q000379:methods*; D004926:Escherichia coli / Q000166:cytology* / Q000502:physiology*; D005285:Fermentation / Q000502:physiology; D005434:Flow Cytometry / Q000379:methods; D007377:Interleukin-3; D008938:Mitosis / Q000502:physiology*; D015202:Protein Engineering / Q000379:methods*; D016185:Receptors, Interleukin-3 / Q000096:biosynthesis* / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D013926:Thrombopoietin / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D007377:Interleukin-3; D016185:Receptors, Interleukin-3; D011993:Recombinant Fusion Proteins; C438891:promegapoietin-1a; D013926:Thrombopoietin