In order to make sure our "consumer" efficient, we should first knock out the luxS gene in our engineering bacteria GR286(a simplified strain of Bacillus amyloliquefaciens LL3). We used a markerless gene replacement method to knock out the luxS gene.
Construction of targeting vector : the upstream and downstream of luxS gene were combined by over-lapping PCR and ligated into plasmid pKSU.
Transformed pKSU-∆luxS into GR286, and selected out positive clones.
The transformants were cultured at 42