Abstract
Macroporous microcarriers are commonly applied to fixed and fluidized bed bioreactors for the cultivation of stringent adherent cells. Several investigations showed that these carriers are advantageous in respect to a large surface area (Griffiths, 1990; Looby, 1990a).
When growing a rC-127 cell line on Cytoline 2 (Pharmacia Biotech), no satisfactory product yield could be achieved. A possible limitation in the supply of nutrient components was investigated to explain these poor results. No significant concentration gradients could be detected. Nevertheless, fluorescence staining revealed a decreasing viability, particularly inside the macroporous structure. Therefore, oxygen transfer to and into the carriers was examined by means of an oxygen microprobe during the entire process. Additional mathematical modeling supported these results.
The maximum penetration depth of oxygen was determined to be 300 μm. A critical value influencing the oxygen uptake rate of the rC-127 cells occured at a dissolved oxygen concentration of 8% of air saturation. A significant mass transfer resistance within a laminar boundary film at the surface of the carrier could be detected. This boundary layer had a depth of 170 μm. The results showed that even a 40% air saturation in the bulk liquid could not provide an efficient oxygenation of the surface biofilm during the exponential growth phase. Fluorescent staining reveals a poor viability of cells growing inside the carrier volume. Thus, oxygen supply limits the growth of rC-127 cells on macroporous microcarriers. Poor process performance and low product yield could be explained this way.
Keywords: dissolved oxygen profile, fibroblasts, fluidized bed, macroporous carrier, oxygen microprobe, recombinantC-127
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References
- Andrews G. Fluidized-bed bioreactors. Biotech and Gen Eng Rev. 1988;6:151–178. [Google Scholar]
- Bassi AS, Rohani S, MacDonald DG. Fermentation of Cheese Whey in an immobilized-cell fluidized bed reactor. Chem Engineering Communications. 1991;103:119–129. [Google Scholar]
- Baumgärtl H and Lübbers DW (1973) Platinum needle electrode for polarographic measurement of oxygen and hydrogen, in: Oxygen Supply, Verlag Urban and Schwarzenberg
- Baumgärtl H, Lübbers DW. Microcoaxial needle sensor for polarographic measurement of local O2 pressure in the cellular range of living tissue. Its construction and properties. In: Gnaiger E., Forstner H, editors. Polarographic oxygen sensors. Springer Verlag: Berlin, Heidelberg; 1983. pp. 37–65. [Google Scholar]
- Beunink J, Baumgärtl H, Zimelka W, Rehm HJ. Determination of oxygen gradients in single Ca-alginate beads by means of oxygen microelectrodes. Experientia. 1989;45:1041–1047. doi: 10.1007/BF01950156. [DOI] [Google Scholar]
- Bignami L, Eramo B, Gavasci R, Ramadori R, Rolle E. Modelling and experiments on fluidized-bed biofilm reactors. Water science and technology. 1991;24(7):47–58. [Google Scholar]
- Bliem R, Katinger H. Scale-up engineering in animal cell technology: part II. TIBTECH. 1988;6:224–230. [Google Scholar]
- Born C, Biselli M and Wandrey C (1995) Oxygen transfer from the gasphase to the immobilized cells in membrane aerated fluidized beds. Proceedings of the 8th meeting of JAACT, Iuzuka, Fukuoka, Japan (in press)
- Brauer H. Grundlagen der Einphasen-und Mehrphasenströmung. Aarau and Frankfurt: Verlag Sauerländer; 1971. [Google Scholar]
- Chang HN and Moo-Young M (1988) Analysis of oxygen transport in immobilized whole cells. Bioreactor immobilized enzymes and cells: fundamentals and applications: 33–51, Elsevier applied science
- Deckwer W-D. Reaktionstechnik in Blasensäulen. Aarau, Frankfurt, Salzburg: Salle-Verlag, Sauerländer-Verlag; 1985. [Google Scholar]
- Griffiths B. Advances in animal cell immobilization technology. Animal Cell Biotechnology. 1990;4:149–166. [Google Scholar]
- Henzler HJ, Kauling DJ. Oxygenation of cell cultures. Bioproc Eng. 1993;9:61–75. doi: 10.1007/BF00369033. [DOI] [Google Scholar]
- Kennard ML, Piret JM. Glycolipid membrane anchored recombinant protein production from CHO cells cultured on porous microcarriers. Biotech and Bioeng. 1994;44:45–54. doi: 10.1002/bit.260440108. [DOI] [PubMed] [Google Scholar]
- Kunii D, Levenspiel O. Fluidization Engineering. Malabar, Florida, USA: RE Krieger publishing company; 1969. [Google Scholar]
- Looby D, Griffiths JB. Immobilization of animal cells in porous carrier culture Tibtech. 1990;8:204–209. doi: 10.1016/0167-7799(90)90177-y. [DOI] [PubMed] [Google Scholar]
- Looby D, Griffiths JB, Mistler M. Verfahrenstechnische Aspekte der Immobilisierung von Säugerzellkulturen auf offenporigen Sintergläsern in Festbett-und Fließbettreaktoren. Chem Ing Tech. 1990;62(7):566–568. doi: 10.1002/cite.330620713. [DOI] [Google Scholar]
- Murdin AD, Kirkby NF, Wilson R, Spier RE. Immobilized Hybridomas: Oxygen diffusion. Animal cell Biotech. 1988;3:55–74. [Google Scholar]
- Nikolai TJ, Hu W-S. Cultivation of mammalian cells on macroporous microcarriers. Enzyme Microb Technol. 1992;14(3):203–208. doi: 10.1016/0141-0229(92)90067-X. [DOI] [PubMed] [Google Scholar]
- Özoguz G, Räbiger N, Baumgärtl H. Membraneinsatz zur Erhöhung der Nitrifikationsleistung durch getrennte Substratversorgung. Bioforum. 1994;17:129–135. [Google Scholar]
- Preißmann A, Bux R, Schorn P and Noé W (1994) Comparative study of the propagation of anchorage-dependent cells using different forms of macroporous microcarrier. Poster presented at the 13th meeting of ESACT, Veldhoven, The Netherlands
- Riethues M, Buchholz R, Onken U, Baumgärtl H, Lübbers DW. Determination of oxygen transfer from single air bubbles to liquids by oxygen microelectrodes. Chem Eng Process. 1986;20:331–337. doi: 10.1016/0255-2701(86)80011-3. [DOI] [Google Scholar]
- Riquarts H-P. Strömungsprofile, Impulsaustausch und Durchmischung der flüssigen Phase in Blasensäulen. Chem Ing Tech. 1981;53:60 ff. doi: 10.1002/cite.330530118. [DOI] [Google Scholar]
- Vournakis JN, Runstadler PW. Microenvironment: The key to improved cell culture products. Biotechnology. 1989;7:143–145. doi: 10.1038/nbt0289-143. [DOI] [Google Scholar]
- Werner RG, Merk W, Walz F. Fermentation with immobilized cell cultures. Drug Res. 1988;38(2):320–325. [PubMed] [Google Scholar]
- Westrin BA, Axelsson A. Diffusion in gels containing immobilized cells: a critical review. Biotech and Bioeng. 1991;38:439–446. doi: 10.1002/bit.260380502. [DOI] [PubMed] [Google Scholar]
- Whitman WG. The two film theory of gas absorption. Chem Metallurg Eng. 1923;29:146–148. [Google Scholar]
- Wiesmann R. Fortschrittsberichte, VDI-Reihe. Düsseldorf: VDI Verlag; 1994. Einfluß der Immobilisierung auf den Stofftransport in biotechnischen Produktionsprozessen. [Google Scholar]
- Wittler R, Baumgärtl H, Lübbers DW, Schügerl K. Investigations of oxygen transfer into penicillium chrysogenum pellets by microprobe measurements. Biotechnol Bioeng. 1986;28:1024–1036. doi: 10.1002/bit.260280713. [DOI] [PubMed] [Google Scholar]