초록
<P>A problem in the mass production of recombinant proteins and biopesticides using insect cell culture is CO<SUB>2</SUB> accumulation. This research investigated the effect of elevated CO<SUB>2</SUB> concentration on insect cell growth and metabolism. Spodoptera frugiperda Sf‐9 insect cells were grown at 20% air saturation, 27<SUP>°</SUP>C, and a pH of 6.2. The cells were exposed to a constant CO<SUB>2</SUB> concentration by purging the medium with CO<SUB>2</SUB> and the headspace with air. The population doubling time (PDT) of Sf‐9 cells increased with increasing CO<SUB>2</SUB> concentration. Specifically, the PDT for 0‐37, 73, 147, 183, and 220 mm Hg CO<SUB>2</SUB> concentrations were 23.2 ± 6.7, 32.4 ± 7.2, 38.1 ± 13.3, 42.9 ± 5.4, and 69.3 ± 35.9 h (n = 3 or 4, 95% confidence level), respectively. The viability of cells in all experiments was above 90%, i.e., while increased CO<SUB>2</SUB> concentrations inhibited cell growth, it did not affect cell viability. The osmolality for all bioreactor experiments was observed to be 300–360 mOsm/kg, a range that is known to have a negligible effect on insect cell culture. Elevated CO<SUB>2</SUB> concentration did not significantly alter the cell specific glucose consumption rate (2.5–3.2 × 10<SUP>−17</SUP> mol/cell s), but slightly increased the specific lactate production rate from −3.0 × 10<SUP>−19</SUP> to 10.2 × 10<SUP>−19</SUP> mol/cell s. Oxidative stress did not contribute to CO<SUB>2</SUB> inhibition in uninfected Sf‐9 cells as no significant increase in the levels of lipid hydroperoxide and protein carbonyl concentrations was discovered at elevated CO<SUB>2</SUB> concentration. © 2016 American Institute of Chemical Engineers <I>Biotechnol. Prog.</I>, 32:465–469, 2016</P>