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Controlled expression and purification of human immune interferon from high‐cell‐density fermentations of Saccharomyces cerevisiae
Author(s) -
Fieschko John C.,
Egan Kevin M.,
Ritch Thomas,
Koski Raymond A.,
Jones Matthew,
Bitter Grant A.
Publication year - 1987
Publication title -
biotechnology and bioengineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.136
H-Index - 189
eISSN - 1097-0290
pISSN - 0006-3592
DOI - 10.1002/bit.260290911
Subject(s) - saccharomyces cerevisiae , immune system , fermentation , yeast , interferon , chemistry , biochemistry , cell , biology , microbiology and biotechnology , virology , immunology
Conditions for high‐cell‐density fermentations of Saccharomyces cerevisiae strains producing recombinant‐DNA‐derived proteins were established. Strains producing human immune interferon (IFN‐γ) from the constitutive PGK promoter failed to grow to high cell densities and exhibited low plasmid stability. Regulated expression of IFN‐γ was obtained in similar strains by employing a hybrid yeast GPD promoter that was subject to carbon source regulation due to the presence of regulatory DNA sequences from the yeast GAL 1,10 intergenic region. IFN‐γ expression programmed by this vector was low during growth on glucose and was induced by galactose. Previously defined fermentation conditions employing glucose as a carbon source were applied to this strain, resulting in high ceil densities with higher plasmid stability. Various methods of galactose induction of IFN‐γ expression in high‐cell‐density fermentations were investigated. Optimal conditions resulted in a 2000‐fold induction and production of 2 g IFN‐γ/L fermentation culture.