In our previous work (Tsao et al., Metabolic Engineering, 12(3), 291-297, 2010), we found the lsr promoter was a bit weak and decided to express T7 polymerase as an amplifier of the original AI-2 initiated gene expression. It was much better than the lsr promoter alone. I wonder if you'd quantified the expression level of your system as a fraction of the total protein? It was hard to follow if yo...