Effect of heptakis (2,6-O-dimethyl) beta-cyclodextrin on the production of pertussis toxin by Bordetella pertussis

The effect of heptakis (2,6-O-dimethyl) beta-cyclodextrin (Me beta CD) on the production of pertussis toxin was evaluated. The addition of Me beta CD to the medium stimulated cell growth and pertussis toxin production. Me beta CD enhanced pertussis toxin production 100 times more in synthetic media, such as Stainer-Scholte medium (D. W. Stainer and M. J. Scholte, J. Gen. Microbiol. 63:211-220), than in Me beta CD-free medium in 2-day shake cultures. Maximum production of pertussis toxin was estimated as 50 mg of protein per liter of culture broth both by in vitro and in vivo assays. Purified toxin was demonstrated to be biochemically and biologically identical to the toxin produced in Me beta CD-free static cultures.

Heptakis(2,6-O-dimethyl)beta-cyclodextrin: a novel growth stimulant for Bordetella pertussis phase I

The effect of cyclodextrins on the growth of Bordetella pertussis Tohama phase I in synthetic medium was evaluated. The addition of cyclodextrins, especially heptakis(2,6-O-dimethyl)beta-cyclodextrin (Me beta CD), to a complete synthetic medium such as Stainer-Scholte medium gave the same number of individual colonies and growth rates as those on Bordet-Gengou medium. Furthermore, with the addition of Me beta CD, growth inhibition by fatty acids such as oleic or palmitic acid was overcome and normal cell growth was observed. This modified Stainer-Scholte medium, designated as cyclodextrin solid medium (CSM), supported excellent growth of 20 lyophilized clinical isolates. Serotypes of the organisms after 10 passages on this CSM plate were not changed. These results suggest that Me beta CD is a significant growth stimulant and CSM is one of the most suitable synthetic media for culture of B. pertussis phase I.

[Kinetic studies of the (1 linked to 4)-alpha-D-glucopyranosyltransferase reaction catalyzed by cyclodextrin glycosyltransferase, particularly the cyclization with amylose, amylopectin and total starch as substrate]

The time course of the (1 leads to 4)-alpha-D-glucopyranosyltransfer reactions catalyzed by the cyclodextrin glycosyltransferase ((1 leads to 4)-alpha-D-glucan: [(1 leads to 4)-alpha-D-glucopyranosyl]transferase (cyclizing), EC 2.4.1.19, CGT) from Klebsiella pneumoniae was studied with several commercial amyloses, potato starch, and amylopectin, respectively. Amyloses were poor substrates for the cyclization reaction. In the initial phase of the transfer reactions, the CGT catalyzed a rapid shortening of the amylose chains. The rate of this shortening reaction was significantly accelerated by addition of maltooligosaccharides. Maximum rate of cyclohexaamylose formation was reached with amylose chains sufficiently short (less than Glc100) for the cyclization reaction. Cyclohexaamylose was formed with maximum rate from amyloses containing amylopectin impurities in the initial phase of the transfer reactions, suggesting that the non-reducing ends of the outer amylopectin chains serve as acceptors for the disproportionation of the amylose. Accordingly, water-soluble, high-molecular-weight products containing higher percentages of lengthened outer-chains were obtained from potato starch or amylopectin. In the course of the transfer reactions, only traces of smaller maltooligosaccharides were detected chromatographically.