RELEASE OF LIPOPOLYSACCHARIDE DURING BORDETELLA-PERTUSSIS GROWTH

The effect of the addition of (2,6-O-dimethyl)-beta-cyclodextrin (Mebe taCD) during growth of Bordetella pertussis in synthetic Stainer-Schol te liquid medium (SS) on lipopolysaccharide (LPS; endotoxin) release w as investigated. The MebetaCD concentration used (3 mg/ml) was chosen according to the optimal level found in previous studies to enhance ma jor soluble antigen production. The profiles in SDS-PAGE (sodium dodec yl sulphate/polyacrylamide gel electrophoresis) of LPS extracted from cells grown in SS and SS + MebetaCD media revealed similar patterns. A lthough the LPS content of whole cells decreased during cell growth, y ields obtained at different growth periods in cyclodextrin medium were lower than those corresponding to SS medium alone. Consequently, the level of LPS released in supernatants of both media increased during c ellular growth. This amount of free LPS was higher in the cyclodextrin liquid medium and became significant at the beginning of the stationa ry growth phase. Binding of cyclodextrin to pertussis cells could acco unt for the data obtained. Similar results were obtained with all spec ies of the genus Bordetella.