I'll bet those alien bacteria are thinking this:
"My fellow bacterians: On Kiau 87th, Bacteria date 8675309-1337, a day that will live in infamy, the planet Earth launched an antibacterial attack on our civilization. We have no choice but to launch a counterattack on -- wait, what's that...lemony smell? AaAaaGGGHHH!!! *SSPLOOORSH!!!Fizzlefizzle*"
Well, they wouldn't be thinking "*SSPLOOORSH!!!Fizzlefizzle*" because they'd be too dead to think so. Ah...bacterial genocide.