Propagation of Mammalian Cells and of Virus in a Self-Regulating Fermentor

Summary A number of different mammalian cell lines were cultivated in large scale batches in a fermentor which controlled the pH value of the medium. Acid produced due to cellular metabolism was titrated by the addition of NaOH. It was shown that the ensuing increase in NaCl concentration had no deleterious effects on cell growth, as long as this increase did not exceed 10% of the regular NaCl concentration in the medium. The production of human adenovirus type 2 (Ad2) in large scale suspension cultures of KB cells was found to be strongly pH dependent; optimal yields were obtained at pH 7.35. Under uncontrolled conditions the pH value in an Ad2-infected culture of KB cells dropped from 8 to 6.9 within a period of 35hr. Monkey Vero cells latently infected with the papova HD virus strain of stump-tailed macaque virus were propagated on a beaded microcarrier in the fermentor. It was shown that such microcarrier complexes were capable of producing viral DNA. This research was supported by grants from the Federal Ministry, Research and Technology, Bonn, Germany, to G. S. (PTB 8061, BCT311) and W. D. (PTB 8059, BCT311).