ecoli chemotaxis reactants

[Andra]

Hello everyone!

I desperately need some help in figuring out what chemicals react as
repellents for e coli, and in particular what toxic/pollutant
chemicals do so. I searched google, but i wasn't able to find anythign
specific.
Are there any pollutants that in small concentrations won't
immediately kill the bacteria, but otherwise will repell it?
I would really appreciate your help with any references or
suggestions.

Thank you, 
Andra