"all bacteria" is a perfectly acceptable term to use in written English.
For example: "The researchers observed the effects of antibiotics on all bacteria in the petri dish."
"We know that not all bacteria are good.
They do not, he said, kill all bacteria, only those that are most susceptible.
Isis Pharmaceuticals in Carlsbad, Calif., is trying to develop drugs that can kill virtually all bacteria.
"All in all, bacteria do not look as if they were the products of chance.
Rather than killing all bacteria, the products destroy only the weakest, leaving stronger ones to survive and multiply.
A drug that would kill all bacteria and another that would boost a person's immune system to withstand any pathogen.
"Good" bacteria, that is (although separating all bacteria into either good or bad categories is probably worryingly oversimplifying things).
Treating healthy animals with antibiotics is even more concerning since not all bacteria are harmful.
All bacteria are prokaryotic, even though many, probably most, are multicelled in nature.
"All bacteria were clearly 'nonself' so simply had to be recognized and dealt with.
Not all bacteria are villains.
