A bacteria makes no decisions. Either a response is molecularly triggered or it is not. There is no “learning”, but there is evolution.
A bacterial population subjected to a novel antibiotic doesn't “learn” to overcome the antibiotic - either they are of a genetic variation subject to the antibiotic or they are not.
That is natural selection of genetic variation - not learning.
The only way a bacteria “learns” is through subsequent rounds of evolution - like how a bacteria “learned” to digest nylon by mutating and further mutating the gene for an esterase enzyme until it was an enzyme that efficiently metabolized nylon.
Learning implies choices based upon knowledge.
A bacteria has no choices or knowledge - only molecular interactions.
So, how does a bacterium or a molecule "know" what to do, in order to manifest an "interaction?" Is this blind chance operating under the temporizing disguise of so-called "natural selection?" From which we can extrapolate so to say that the entire universe is the result of "chance," not God's creative Word?
You assert much, my friend. But never tell me on what basis your assertions can possibly rest.
Take, for example, a study I read regarding a laboratory experiment with amoebae.
Here was an amoeba, sitting in a petri dish culture into which a couple of grains of China ink was introduced. At first, the amoeba reached out as if to digest it, as potential "food." But almost instantly, it "spitted it out." It somehow knew that China ink was not food for it. So, the next time grains of China ink were introduced, the amoeba did not even approach them at all.
Looks to me like the amoeba "learned something." And in order to learn something, some form of consciousness must be present. Surely not the full-blown self-consciousness of a human being — said to be the only species on earth that possesses this quality. But a sort of consciousness sufficient to learn something new by trial and error.
Which seems to be more than some people can do, nowadays.