CULTIVATION OF RECOMBINANT ESCHERICHIA-COLI AND PRODUCTION OF FUSION PROTEIN IN 60-1 BUBBLE COLUMN AND AIRLIFT TOWER LOOP REACTORS

E. coli K12 with multicopy plasmid (lambda P(R)-promoter and temperature-sensitive lambda cI 857 repressor) was cultivated in 60-l bubble column and airlift tower loop reactors. The medium composition, cell concentration, and intracellulary enzyme activity were monitored on-line during batch, fed-batch, and continuous cultivations. The specific growth rates, cell mass yield coefficients, plasmid stabilities, productivities of the amount of active fusion protein (beta-galactosidase activity), concentrations and yields of acetic acid, and volumetric oxygen transfer coefficient were evaluated for different medium compositions and cultivation conditions. The enzyme activity was also monitored during the temperature induction. The results evaluated in the 60-l bubble column and airlift tower loop reactors are compared with those evaluated in a 1-1 stirred-tank reactor.