Effect of temperature and oxygen on cell growth and recombinant protein production in insect cell cultures

The effect of temperature and O2 saturation on the production of recombinant proteins beta-galactosidase and human glucocerebrosidase by Spodoptera frugiperda cells (Sf9) infected with recombinant Autographa californica nuclear polyhedrosis virus was investigated. The rates of cell growth, glucose consumption, O2 consumption and product expression were measured at temperatures between 22 degrees C and 35 degrees C. The results indicated that possible O2 limitation may be alleviated without compromising the maximum cell yield by lowering the incubation temperature from 27 degrees C to 25 degrees C. The expression level of the recombinant proteins at 27 degrees C was similar to that obtained at 22 degrees C and 25 degrees C; lower protein yields were obtained at 30 degrees C. An increase in temperature from 22 degrees C to 27 degrees C led to earlier production of the proteins and to an increase in the proportion of the product released outside the cells.