PRODUCTION AND QUALITY ANALYSIS OF PR55GAG PARTICLES PRODUCED IN BACULOVIRUS-INFECTED INSECT CELLS

In this work Sf-9 cells previously adapted to SF900II and EXCELL 401 s erum-free media (SFM) were grown and infected at different agitation r ates in order to study the effects of power input upon cell growth, in fection and production of Pr55gag particles in both SFM. Maximum cell concentration increased from 3 x 10(6) to 6 x 10(6) cells cm(-3) and 6 .5 x 10(6) cells cm-3 when the agitation increased from 80 to 250 rpm or sparged aeration (0.01 vvm at 170 rpm) is used, clearly indicating that cell growth is limited by gas transfer. The specific productivity increased 3.5-fold when the agitation rate was increased from 80 to 1 70 rpm, indicating that in SFM cell infection is also limited by gas t ransfer. The highest product concentration was obtained in SF900II at 120 h post-infection (hpi). The product quality analysis showed that S F900II is the best medium for production of Pr55gag particles and that a careful optimisation of the harvest time is required. The maximum p roduct titre was obtained at 120 hpi, 48 h after the achievement of th e highest quality. (C) 1998 SCI.