What characteristic of the polymerase isolated from thermus aquaticus makes it unique and highly useful for maintaining the enzyme efficiency during pcr?

Thermostability

Explanation:

Thermus aquaticus is a species of bacteria that can tolerate extremly high temperatures and it is the source of the heat-resistant enzyme Taq DNA polymerase used in PCR. The advantages of this enzyme are its thermostabilty (temperature optimum 80°C) so it doesn't have to be added after every cycle of thermal denaturation of the DNA and also that it can be isolated in a pure form.