title: Overproduction of delta-endotoxins by sporeless Bacillus thuringiensis mutants obtained by nitrous acid mutagenesis.
abstract: 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.
authors.affiliation: Laboratory of Biopesticides, Centre of Biotechnology of Sfax, P.O. Box 1177, 3018, Sfax, Tunisia.
authors.forename: Saoussen
authors.initials: S
authors.lastname: Ben Khedher
authors.forename: Nabil
authors.initials: N
authors.lastname: Zouari
authors.forename: Nadia
authors.initials: N
authors.lastname: Messaddeq
authors.forename: Patrick
authors.initials: P
authors.lastname: Schultz
authors.forename: Samir
authors.initials: S
authors.lastname: Jaoua
mesh_terms: 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*
chemical_list: D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D004731:Endotoxins; D006460:Hemolysin Proteins; D009153:Mutagens; C030956:insecticidal crystal protein, Bacillus Thuringiensis; D009608:Nitrous Acid