Recombinant rabies virus glycoprotein (rRVGP) was expressed in Drosophila melanogaster Schneider 2 (S2) cells. The cDNA encoding the entire RVGP gene was cloned in an expression plasmid under the control of the constitutive actin promoter (Ac), which was co‐transfected into S2 cells together with a hygromycin selection plasmid. Selected S2 cell populations (S2AcRVGP) had a decreased ability to grow and consume substrates, when compared to the non‐transfected cells (S2). They were shown, by PCR, to express the RVGP gene and mRNA and, by immunoblotting, to synthesize the rRVGP in its expected molecular mass of 65 kDa. ELISA kinetic studies showed the rRVGP expression in cell lysates and supernatants attaining concentrations of 300 μg/L. By flow cytometry analysis, about 30% of the cells in the co‐transfected populations were shown to express the rRVGP. Cell populations selected by limiting dilution expressed higher rRVGP yields. Mice immunized with rRVGP were shown to synthesize antibodies against rabies virus and be protected against experimental infection with rabies virus. The data presented here show that S2 cells can be suitable hosts for the rRVGP expression, allowing its synthesis in a high degree of physical and biological integrity.

The present study investigated the effects of agitation speed, N (200, 500, 600 or 700 rpm), and dissolved oxygen concentration, C (120, >70, 70, 60, 10 or < 10%), on red pigment and citrinin production by Monascus purpureus ATCC 36928, cultivated in liquid medium by a batch process. The gas flow rate was the same for all runs with C controlled by means of the incoming gas composition control (air/N2 or air/O2). From the response surface plots it can be verified that the effect of C was greater than that of N on the production of both metabolites. The absorbance for red pigments varied from 1.6 U (C< 10%; N=200 rpm) up to 3.3 U (C=60%; N=600 rpm), an increase of 106%, while citrinin concentration increased 257%, from 14.2 to 50.7 mg.L-1. The most appropriate conditions were C=60% and N=600rpm, under which the highest red pigment absorbance (3.3U) and half of the highest citrinin concentration were obtained.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP