title: Process parameter shifting: Part II. Biphasic cultivation-A tool for enhancing the volumetric productivity of batch processes using Epo-Fc expressing CHO cells.
abstract: Regulation of cell growth and protein expression potentially results in a sustainable enhancement of the volumetric productivity in a fermentation process. Following a biphasic cultivation strategy the process initially passes through a cell proliferation phase to generate a sufficiently high viable cell mass. In the subsequent production phase cells are maintained viable and productive without significant cell proliferation leading to increased viable cell days and product yields. In a previous work we have shown that the well directed alteration of the process environment based on process parameter shifting is a promising tool to regulate cell growth and protein expression. In continuation of this work we investigated process parameters which have been identified to affect cell proliferation in favor of an increased specific productivity and total product yield in a series of biphasic batch cultivation experiments. In most of these processes the integral of viable cells and the specific productivity were increased leading to a significant improvement of both final product concentration and volumetric productivity. In addition, combined parameter shifts (pH 6.90/30 degrees C and pH 6.90/33 degrees C) exerted a synergistic effect on product quality. The loss of product sialylation which occurred at reduced temperatures was prevented by simultaneously reducing the external pH. In conclusion, biphasic cultivation based on combined shifting of process parameters is a suitable tool for controlling cell proliferation and protein expression of mammalian cells in a batch bioreactor leading to enhanced volumetric productivities and therefore offers an enormous potential for bioprocess optimization.
authors.affiliation: Department of Biotechnology, Institute of Applied Microbiology, University of Natural Resources and Applied Life Sciences Vienna, Muthgasse 18, 1190 Vienna, Austria.
authors.forename: Evelyn
authors.initials: E
authors.lastname: Trummer
authors.forename: Katharina
authors.initials: K
authors.lastname: Fauland
authors.forename: Silke
authors.initials: S
authors.lastname: Seidinger
authors.forename: Kornelia
authors.initials: K
authors.lastname: Schriebl
authors.forename: Christine
authors.initials: C
authors.lastname: Lattenmayer
authors.forename: Renate
authors.initials: R
authors.lastname: Kunert
authors.forename: Karola
authors.initials: K
authors.lastname: Vorauer-Uhl
authors.forename: Robert
authors.initials: R
authors.lastname: Weik
authors.forename: Nicole
authors.initials: N
authors.lastname: Borth
authors.forename: Hermann
authors.initials: H
authors.lastname: Katinger
authors.forename: Dethardt
authors.initials: D
authors.lastname: Müller
mesh_terms: D000818:Animals; D019149:Bioreactors / Q000382:microbiology*; D016466:CHO Cells / Q000166:cytology / Q000502:physiology*; D018929:Cell Culture Techniques / Q000379:methods*; D003198:Computer Simulation; D006224:Cricetinae; D003412:Cricetulus; D004921:Erythropoietin / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007141:Immunoglobulin Fc Fragments / Q000235:genetics / Q000378:metabolism; D007074:Immunoglobulin G / Q000235:genetics / Q000378:metabolism*; D008954:Models, Biological; D010100:Oxygen / Q000378:metabolism*; D010101:Oxygen Consumption / Q000502:physiology; D015202:Protein Engineering / Q000379:methods; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D013696:Temperature
chemical_list: D007141:Immunoglobulin Fc Fragments; D007074:Immunoglobulin G; D011993:Recombinant Fusion Proteins; D004921:Erythropoietin; D010100:Oxygen