Overview
In our iGEM project "Exterminatrix," we engineered an Escherichia coli （E. coli）-based attract-and-kill system for termite control (Coptotermes formosanus), addressing environmental risks of chemical pesticides. The wet lab workflow integrated plasmid construction, transformation, expression validation (via fluorescence microscopy and Western blotting). Functional assays to produce hydroquinone (HQ) as a phagostimulant through Cytochromes P450 (CYP450)-catalyzed phenol hydroxylation.
Testing wild-type and double-mutant (A83F/A329F) variants in E. coli BL21 under IPTG induction, where the mutant showed enhanced production. HQ was then combined with tea polyphenols at a 1:5 ratio and applied to pine baits, which effectively lured termites. For the termite-killing part, toxins like melittin and hecate (expressed under FNR promoters) and EcTI (expressed under constitutive J23100) were tested. These toxins demonstrated antimicrobial effects in bacterial growth assays, reduced motility in model organisms, and inhibited protease activity. Eventually, they achieved independent lethality in termite trials conducted on HQ-laced baits. This comprehensive pipeline ensured robust, eco-friendly biocontrol components, as illustrated in the flowchart below:
Fig. 1 Experiment Flow Overview