MUTANT OF BACILLUS THURINGIENSIS DEPOSITED AS SUBSP. TENEBRIONIS DSM 5480, METHOD FOR THE PREPARATION THEREOF AND PESTICIDE CONTAINING THE SAME

摘要

A mutant of Bacillus thurinqiensis, wherein the mutant is deposited mutant B. thurinsiensis subs. tenebrionis, DSM 5480, which mutant is capable of producing twice as much or more of insecticidal delta-endotoxins as compared to its parent strain and is used for the control of lepidopteran, dipteran pest insects, especially for the control of coleopteran pest insects. In a method of mutating Bacillus thuringiensis strains and selecting such mutants that are capable of producing substantially larger amounts of delta endotoxins than their parent strains, the parent strain is: i) treated with a mutagen, said mutagen may be any suitable conventional chemical mutagen, such as N-methyl-N'-nitro-N- nitrosoguanidine, or ethyl methanesulfonate, or the parent strain may be treated with electromagnetic radiation, such as r-, X-ray-, or UV-radiation; ii) the thus treated mutants are grown on a medium containing phosphate and, optionally, 0.57 g/l of MgCl2 and 20 g/l of gelrite suitable for the selection of asporogenous and/or oligosporogenous strains, iii) translucent colonies are selected and grown in a medium that does not fluidize on heating, and iv) truly asporogenous strains are deselected by subjecting the colonies to a heat treatment.