bio ee inspo?

I want to do a biology ee on microbiology. Originally I wanted to do virology but at my school we can't work with viruses and I don't want to use secondary data. We do have e.coli at my school, so now I decided to do bacteriology.

What insterseting question can I write about and do an experiment about with e.coli? The only three things I found intersting so far was that they can be genetically engineered to be autotrophic (sounds too complicated for a highschool lab), antibiotic resistance (my school doesn't allow us to develop that) and immunology (I can't use human tissue or infect someone obviously).

Has anyone done an ee with bacteria? If so can you tell me what it was about? I'm really lost on what to do, it'd be really helpful to have some examples of what's feasible.