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Effect of elevated oxygen and glutamine levels on foreign protein production at high cell densities using the insect cell‐baculovirus expression system
Author(s) -
Taticek R. A.,
Shuler M. L.
Publication year - 1997
Publication title -
biotechnology and bioengineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.136
H-Index - 189
eISSN - 1097-0290
pISSN - 0006-3592
DOI - 10.1002/(sici)1097-0290(19970420)54:2<142::aid-bit6>3.0.co;2-l
Subject(s) - trichoplusia , oxygen , alkaline phosphatase , glutamine , biochemistry , cell culture , limiting oxygen concentration , yield (engineering) , biology , glutamine synthetase , cell , chemistry , enzyme , microbiology and biotechnology , amino acid , noctuidae , botany , genetics , materials science , organic chemistry , larva , metallurgy
Per cell protein expression in virally‐infected insect cells declines significantly at high cell density resulting in a decrease in volumetric productivity. Specific protein expression levels in Spodoptera frugiperda (Sf‐21) cells could be increased at high cell densities by increasing the oxygen supply and by supplementing the medium with glutamine post‐infection. β‐Galactosidase yield was increased from 411 to 855 IU/ml by increasing the glutamine concentration in the medium by 46% and increasing the gas phase oxygen concentration from 21 to 80%. Similarly, the yield of a secreted alkaline phosphatase was increased from 14.2 to 26.2 IU/mL using the same conditions. Part of the increase in production with Sf‐21 culture was due to increased release to the extra‐cellular compartment at the higher oxygen concentrations. Increasing the gas phase oxygen concentration to 95% in conjunction with a 100% increase in glutamine and glucose concentrations did not improve the yield any further. Peak production under elevated oxygen and nutrient conditions occurred at 72 h about 24–48 h earlier than under normal conditions. In a Trichoplusia ni cell line (BTI‐TN‐5B1‐4), the maximum secreted alkaline phosphatase activity was increased from 10 to 27.2 IU/mL by similarly manipulating the oxygen supply. © 1997 John Wiley & Sons, Inc. Biotechnol Bioeng 54: 142–152, 1997.