Overproduction of delta-endotoxins by sporeless Bacillus thuringiensis mutants obtained by nitrous acid mutagenesis.
Asporogenic and oligosporogenic Bacillus thuringiensis mutants having the ability to overproduce insecticidal crystal protein were generated by using nitrous acid (50 mg/ml), as chemical mutagenic agent. Insecticidal crystal proteins produced by asporogenic mutants remained encapsulated within the cells. Delta-endotoxin production by most of mutants was improved compared to the corresponding wild strains BNS3 and a mutant M26. The overproduction by asporogenic and oligosporogenic mutants was attributed to defect in genes involved in sporulation and to random mutations affecting cell metabolism at different pathways and delta-endotoxin synthesis. Sporeless bioinsecticides could be developed based on stable and environmentally safe Bacillus thuringiensis mutants.
Ben Khedher
Saoussen
S
Laboratory of Biopesticides, Centre of Biotechnology of Sfax, P.O. Box 1177, 3018, Sfax, Tunisia.
Zouari
Nabil
N
Messaddeq
Nadia
N
Schultz
Patrick
P
Jaoua
Samir
S
D001413:Bacillus thuringiensis / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism*; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000096:biosynthesis*; D004731:Endotoxins / Q000096:biosynthesis*; D006460:Hemolysin Proteins / Q000096:biosynthesis*; D016296:Mutagenesis; D009153:Mutagens / Q000378:metabolism*; D009608:Nitrous Acid / Q000378:metabolism*
D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D004731:Endotoxins; D006460:Hemolysin Proteins; D009153:Mutagens; C030956:insecticidal crystal protein, Bacillus Thuringiensis; D009608:Nitrous Acid