Yes. It is in a dormant state (like a stand by mode)
How is "dormant" different from "dead" (or "alive" for that matter)? I don't think that's going to be an easy one to answer without begging the question of the definition of "alive".
but still communicates with itself and the environment,
Not exactly, and that's where things get fuzzy. The anthrax spore does not "communicate with itself" unless triggered. Its internal processes have ceased. It exchanges nothing with the outside environment (which is exactly why it can survive conditions that would otherwise kill, starve, suffocate, or poison it to death). It performs no enzymatic activity or macromolecular synthesis or metabolic processes. It requires no source of energy, because it is completely inactive. It can remain in this state for thousands of years -- or hundreds of millions of years. There is, in short, no activity, no "exchange of information" during the dormant state.
Absent the appropriate trigger(s), it's as dead and inactive as an insect in amber.
So by what measure is it alive?
when a food supply exists (like in a human lung) - it comes out of the dormant state.
Only because chemically, it's "set" like a mousetrap, and can *begin* to operate again if its "locks" are tickled open by the appropriate chemical "keys", setting things into motion again. But it's incorrect to say that it "exchanges" information during its dormancy, as if it's constantly "testing" and "evaluating" conditions. It's not. It's no more communicating than is a music box motionlessly awaiting its lid to be raised.
So -- is an anthrax spore alive?
Ichthumon wrote - Is an anthrax spore alive?
Alamo Girl repied - Yes. It is in a dormant state (like a stand by mode) but still communicates with itself and the environment, when a food supply exists (like in a human lung) - it comes out of the dormant state.
As a microbiologist I would say that Alamo Girl got it exactly right. I would like to hear her take on viruses. Personally, I don't consider them to be life - but instead the code of life run amuck. Calling a computer virus a virus is very apt. It is code designed to take over or disrupt and then just replicate itself.