Process for plasmid dna fermentation

Abstract

Improvements in plasmid DNA production technology are needed to insure the economic feasibility of future DNA vaccines and DNA therapeutics. General methods are described, by means of which it is possible to dramatically increase plasmid DNA productivity in a fermentor. These processes feature fed-batch fermentation strategies, combined with novel growth and induction phase temperature shifts.

1 . A method for fed-batch fermentation production of covalently closed super-coiled plasmid DNA comprising the steps of: A) growing bacterial cells containing a plasmid, cosmid, or bacterial artificial chromosome replicon at a reduced temperature during a fed-batch phase; and B) restricting growth rate of the bacterial cells during the fed-batch phase by nutrient limitation; and C) inducing plasmid production by increasing temperature; and D) continuing growth at elevated temperature to accumulate plasmid product.