ISSN:
0006-3592
Keywords:
insect cells
;
baculovirus
;
protein expression
;
high cell density
;
Chemistry
;
Biochemistry and Biotechnology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
,
Process Engineering, Biotechnology, Nutrition Technology
Notes:
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.
Additional Material:
12 Ill.
Type of Medium:
Electronic Resource
