CHARACTERIZATION OF BACILLUS-THURINGIENSIS AND RELATED BACTERIA BY RIBOSOMAL-RNA GENE RESTRICTION-FRAGMENT-LENGTH-POLYMORPHISMS

Ribosomal RNA gene restriction patterns have been determined for 43 st rains of Bacillus thuringiensis representing 10 serovars and eight ref erence strains of B. anthracis, B. cereus and B. mycoides. Strains wit hin a B. thuringiensis serovar produced highly related or identical ri botype patterns: in particular, 12 strains of serovar israelensis, fiv e strains of serovar kurstaki, two strains of serovar galleriae and th ree strains of serovar aizawa produced ribotype patterns consistent wi th serotype designations. Moreover, variety tenebrionis (serotype 8a8b ). a coleopteran pathogen, could be distinguished from the more common lepidopteran pathogens of this serotype (serovar morrisoni) by riboty ping. The correlation of ribotype patterns with serotype suggests a cl onal population structure for B. thuringiensis.