IDENTIFICATION OF BETA-EXOTOXIN PRODUCTION, PLASMIDS ENCODING BETA-EXOTOXIN, AND A NEW EXOTOXIN IN BACILLUS-THURINGIENSIS BY USING HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

An improved high-performance liquid chromatography separation was developed to detect and quantify β-exotoxin production in Bacillus thuringiensis culture supernatants. Exotoxin production was assigned to a plasmid in five strains, from three subspecies (B. thuringiensis subsp. thuringiensis serotype 1, B. thuringiensis subsp. tolworthi serotype 9, and B. thuringiensis subsp. darmstadiensis serotype 10). A new exotoxin, called type II β-exotoxin in this report, was discovered in B. thuringiensis subsp. morrisoni serotype 8ab, purified, and partially characterized. This material is more specific than type I β-exotoxin and is very active against the Colorado potato beetle, Leptinotarsa decemlineata.