| 摘要 |
NEW MATERIAL:To provide a Bacillus.thuringlensis variety crustaki variant losing a spore-forming ability and a part or all of plasmid holding a gene coding an insecticidal protein having an insecticidal ability against Lepidoptera insects. USE:An insecticide. PREPARATION:For example, the spores of Bacillus.thuringlensis variety crustaki HD-1 are suspended in a phosphate buffer solution, heated at 70 deg.C for 20min, mixed with a mutagen such as ethylmethane sulfonic acid, shaken and subsequently centrifuged. The prepared precipitates are cultured in a slant medium, and a sporedefective variant is selected from the cultured products and subjected to a plasmid-removing treatment to provide a MA31-0 strain. The prepared MA31-0 strain and the original strain not subjected to the mutation treatment are shaken and cultured in test tubes, respectively, and subsequently mixed with each other, and the mixture is coated on an agar medium and cultured at 30 deg.C for 3 days to provide a variant strain MA31-2. |
