bacteria are fascinating. when i was a lab tech, my favorite department was microbiology. there are so many cool things about micro. first of all, you are actually working with living, growing organisms. they have likes and dislikes. some like blood agar, some like sugar, some like oxygen while some thrive without oxygen, etc. my favorite part about micro was that it was like being a detective, having to isolate and identify the bacteria. it's a very 'hands-on' process, or at least it was back in the day for me.
i've collected some links featuring bacteria/petri dish related "art".
fractal geometry panorama
gardens in a petri
more gardens in a petri
petri dish project
bacterial photographs - awesome!
volvox...this one is so pretty! (algae not bacteria)