taq polymerase is special because it is very stable at high temperatures and will not denature even at the 90 degree step of pcr. taq polymerase is so heat stable because it was extracted from the bacterium thermus aquaticus, which is found in hot springs and geezers

Taq Polymerase is an important enzyme component involved in the PCR reaction. Its A DNA polymerase and its role is to elongate the growing strands of DNA during the extension process. Since the Extension process in a PCR works at a temperature which a human DNA polymerase cannot remain active, the Taq polymerase obtained from Thermus aquaticus (living in the hot springs) are used and hence these enzymes are thermo stable.

to store taq DNA polymerase at low temperature is to make it viable or we can say inactive for sometime. it doesnt die or decay but remains viable.

Thomas D. Brock, An American Microbiologist

Taq polymerase, the enzyme used frequently in Polymerase Chain Reaction, is extracted from Thermophilus aquaticus, a thermophilic bacteria.