Decoupling sporulation from insecticidal activity in Bacillus thuringiensis BLB1 strain through Iterative UV...

Area of Science:

• Microbial biotechnology
• Insect toxicology
• Genomics

Background:

• Bacillus thuringiensis (B. thuringiensis) is a widely used microbial biopesticide.
• Persistence of B. thuringiensis spores raises ecological and safety concerns.
• Developing strains with reduced sporulation is key for sustainable pest management.

Purpose of the Study:

• Generate and characterize novel oligosporogenic mutants of B. thuringiensis BLB1.
• Investigate the genetic basis of reduced sporulation using Whole Genome Sequencing (WGS).

Main Methods:

• Iterative UV mutagenesis of B. thuringiensis BLB1.
• Screening for mutants with reduced sporulation and maintained crystal production.
• Whole Genome Sequencing (WGS) and comparative genomic analysis.

Main Results:

• Two mutants (T3, T8) showed delayed sporulation and altered glucose consumption.
• Mutants retained high insecticidal activity against key lepidopteran pests.
• WGS confirmed no mutations in cry genes, explaining preserved toxicity.

Conclusions:

• Iterative UV mutagenesis successfully decoupled sporulation from insecticidal activity.
• Mutants T3 and T8 are promising for safer biopesticide applications.
• Reduced environmental persistence combined with strong biocontrol efficacy.