Bt toxin engineering
Toxin obtainable by truncation or synthesis
fused to tetR promoter (B. cereus)
- expressed vegetatively, rather than only in spores
- much more efficient (continuous culture production)
multiple toxins combined into single gene
- add to third Bt strain, kills multiple pests
domain engineering
- domainI: receptor binding (different receptors)
- domainIII: toxin itself
- multiple receptor toxin -- harder to become resistent