[Site-specific restrictases from Bacillus thuringiensis var. Kumantoensis].

The efficiency of bacteriophages CP-54 and CP-55 plating on Bacillus thuringiensis var. kumantoensis H18 (Kum) is decreased about 10-fold as compared with the efficiency of plating on Bacillus thuringiensis var. galleriae H5 (Gal).

[Variability of Bacillus thuringiensis bacteriophages with C2-morphology].

Biological as well as physicochemical properties of Bacillus thuringiensis bacteriophages "17" and "7/13" having C2-morphology and isolated from factory phagolysates were studied. The bacteriophages are identical in the lytic spectrum++, morphology, size, GC-content, have the same buoyant density. The physical map for restriction endonucleases EcoRI, HindIII, SalGI and MvaI has been constructed of the bacteriophages DNA.

[Extracellular serine proteinase of Bacillus thuringiensis].

Pure extracellular serine proteinase has been isolated from a broth filtrate of Bacillus thuringiensis, strain 69-6R by fractionation with ammonium sulfate and affinity chromatography on Sepharose 4B derivatives containing p-(omega-aminomethyl)-phenylboronic acid and cyclopeptide bacillichin as ligands. The enzyme is completely inactivated by phenylmethylsolfonyl fluoride, a specific reagent for serine proteinases, has the molecular weight of 29 000 and pI of 8.4, reveals maximal activity and stability at pH 8.

[Electron microscopic study of the interaction between phages and Bacillus thuringiensis cells].

The interaction of phages belonging to different morphological groups with the cells of Bacillus thuringiensis var. galleriae R and S variants was studied. No adsorption of phages Tg11 and Tg18 on the cells of R variant was found upon infection in a liquid medium.