Dr. Timothy Hovanek identified the proper species of nitrifying bacteria when he worked for Marineland.
They do not enter a dormant phase, but somehow Marineland was able to package them. They package needed to be kept within certain temperature parameters, neither too hot, nor too cold.
They got a patent and started selling it as Bio Spira. One package for fresh water, one package (different species) for salt water.
The fresh water product became the property of Tetra, with the patent.
Espacenet - Bibliographic data
In the Description of the patent are some comments about including materials to keep the bacteria viable in storage.
It does work. If you are in need of these bacteria, this is a valid product.
The problem is that you do not know if the package has been handled correctly. This was one of the problems with the original Bio Spira. Somewhere during shipping and handling the package was over heated or frozen. The fish keeper would try to use it per label directions, and end up with a tank full of fish and no live bacteria. This is still possible, which is why I suggest buying it from a reputable store, and doing the fishless cycle with this material. If the product is good, your fishless cycle will be complete in 24-48 hours. If the product is bad (dead bacteria) then you are not stuck with a tank full of fish and no bio filter. Another way to use it is to get just a few fish, and dose a small amount of the product. If it works, then go get more fish and dose more product. It can be kept in the frige and dosed each time you add fish. If it does not work, then you have only a few fish in the tank, and can probably do a fish-in cycle, or add more plants, and the plants will be the biofilter.