Mutant of Bacillus thuringiensis micro-organism deposited as subsp. tenebrionis DSM 5480, process of its preparation and pesticidal agent containing thereof

摘要

Mutant or variant (I) of Bacillus thuringiensis capable of producing high amts. of insecticidal delta-endotoxins compared to its parent strain is new. Also claimed is a method of mutating B. thuringiensis strains, and selecting mutants which can produce larger amts. of delta endotoxins than their parent strains, where the parent strain is: (1) treated with a mutagen; (2) the resultant mutants are grown in a medium used for the selection of asporagenous and/or oligosporagenous strains; (3) transulcent colonies are selected and grown in a medium that does not fludise on heating; and (4) truly asporogenous strains are deselected by subjecting the colonies to a heat treatment.