Overproduction of delta-endotoxins by sporeless Bacillus thuringiensis mutants obtained by nitrous acid mutagenesis

Curr Microbiol. 2011 Jan;62(1):38-43. doi: 10.1007/s00284-010-9670-x. Epub 2010 May 20.


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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacillus thuringiensis / drug effects*
  • Bacillus thuringiensis / growth & development
  • Bacillus thuringiensis / metabolism*
  • Bacillus thuringiensis Toxins
  • Bacterial Proteins / biosynthesis*
  • Endotoxins / biosynthesis*
  • Hemolysin Proteins / biosynthesis*
  • Mutagenesis
  • Mutagens / metabolism*
  • Nitrous Acid / metabolism*


  • Bacillus thuringiensis Toxins
  • Bacterial Proteins
  • Endotoxins
  • Hemolysin Proteins
  • Mutagens
  • insecticidal crystal protein, Bacillus Thuringiensis
  • Nitrous Acid