Improved pertussis toxin production by Bordetella pertussis through adjusting the growth medium's ionic composition.

Ionic composition and total ionic concentration of the growth medium were important factors in limiting productivities in aerated reactors used for the production of pertussis toxin and other antigens by Bordetella pertussis. Salt concentration has opposing effects on cell growth of wild-type B. pertussis and specific toxin formation. Sodium ion concentrations below 140 mM correlated with a precipitous decline in specific yields of pertussis toxin, an otherwise growth-associated product. High salt concentrations in the medium resulted in lower final cell concentrations but did not affect initial growth rates. A new medium is proposed that allows a 60 to 70% increase in both cell and toxin yields by replacing the sodium chloride in the 'cyclodextrin liquid' (CL) medium with additional monosodium glutamate which provides both the sodium and the carbon and energy source.