Two Types of Entomocidal Crystals of Bacillus thuringiensis ssp. finitimus Have the Same Set of Unique Delta-Endotoxins

L. P. Revina^*, I. A. Zalunin, I. V. Krieger, N. M. Tulina, Ya. A. Wojciechowska, E. I. Levitin, G. G. Chestukhina, and V. M. Stepanov

Institute of Genetics and Selection of Industrial Microorganisms, Dorozhnyi Proezd 1, Moscow, 113545 Russia; E-mail: chestukhina@hotmail.com

^* To whom correspondence should be addressed.

Received January 25, 1999; Revision received April 9, 1999

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The strain B-1166 differs from the other strains of Bacillus thuringiensis ssp. finitimus because it has two crystal types with different localization in the sporulating cell, i.e., inside and outside of exosporium membrane. Two dissociants of the strain were obtained containing only one of the crystal types. The initial strain produces at least three various delta-endotoxins (Fin2, Fin3, and Fin5) differing from all other known entomocidal proteins; Fin2 and Fin3 are similar to each other but differ from Fin5. Both crystal types contain the same endotoxins (Fin2, Fin3, and Fin5). In the B-1166 strain the site of crystal deposition is not determined by their protein composition.

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KEY WORDS: Bacillus thuringiensis, delta-endotoxin, exosporium

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