| 摘要 |
The present invention relates to a mutant of Bacillus thuringiensis or B. cereus, which has a partial deficiency of the restriction barriers which are intrinsically present in the non-mutated starting strain and can therefore be transformed significantly better than said, non-mutated starting strain when vector DNA from a heterologous intermediate host which is naturally subject to restriction in B. thuringiensis and/or B. cereus is used. Also embraced are processes for the preparation of said mutants, which are based on a targeted enrichment of spontaneous mutants, and processes for the cloning of genes or other DNA sequences using said restriction-deficient mutants of Bacillus thuringiensis and/or Bacillus cereus. |
