THE INDUCTION OF BACILLUS-THURINGIENSIS NEW TYPES BY FOREIGN DNA

The nucleotide and deduced amino acid sequences of the Bacillus thurin giensis delta-endotoxin gene suggest that the specific activity of thi s kind of genes is concentrated in a short region in the gene. Attempt s to develop new B. t. strains were carried out through the introducti on of foreign DNA. B. t. efficiency was found to increase by transform ation with DNA from differnt sources. Fenugreek DNA was able to produc e highly efficient transformants in two B. t. strains. The other three -sources of DNA, linen 'seeds, cardamon seeds and Streptomyces thermov iridis, produced transformants with moderate activity. Moreover, trans formation with fenugreek DNA was able to produce new B. t. types which are highly potent vs. Tribolium confusum. Great variability in the po tency of transformants single colonies vs different insect species was observed offering a good manner for selecting new types with high pot ency vs. some insect species.