Bacillus thuringiensis strains and their insecticidal proteins

An isolated variant or mutant of the protein of SEQ ID NO:5, which protein variant or mutant has insecticidal activity against a Lepidopteran insect, and which variant or mutant comprises an amino acid sequence which is encoded by a DNA sequence that hybridizes under stringent hybridization conditions to the DNA sequence of nucleotide position 797 to nucleotide position 2641 of SEQ ID NO:

• 4, wherein said stringent hybridization conditions are established using the following steps:
• a) immobilizing DNA fragments on a filter;
• b) prehybridizing said filter for 1 to 2 hours at 42° C. in 50% formamide, 5× SSPE, 2× Denhardt's reagent and 0.1% SDS, or for 1 to 2 hours at 68° C. in 6× SSC, 2× Denhardt's reagent and 0.1% SDS;
• c) adding a hybridization probe which has been radiolabeled;
• d) incubating for 16 to 24 hours;
• e) washing said filter for 20 minutes at room temperature in 1× SSC, 0.1% SDS;
• and
• f) washing said filter three times for 20 minutes each at 68° C. in 0.2× SSC, 0.1% SDS;
• and
• g) autoradiographing said filter by exposing said filter for 24 to 48 hours to X-ray film at −70° C. with an intensifying screen.