ABSTRACT
The choice of species and cell line used as expression system for a given protein is probably one of the most important strategic decisions taken in the bioprocess program. The primary choices include use of bacteria (Escherichia coli, Bacillus subtilis, Lactococcus lactis), yeast (Saccharomyces cerevisiae, Pichia pastoris), and mammalian cells (Chinese hamster ovary, CHO; baby hamster kidney). The baculovirus expression system in insect cells (sf9) is used (e.g., to express beta-glucosidases) but remains to be fully exploited; transgenic animal products are still not approved for human use though one application for an antibody derived from goat milk is pending approval.
