An adaptation you would expect polar microbes to have would be in their membranes.

Cholesterol

An adaptation you would expect polar microbes to have would be _cholesterol_ in their membranes.

Explanation:

The cholesterol  intersperse in the  phospholipid asociated at the lipid bilayer, this allows at the membrane to keep flowing and not freezing, so the cell keeps its normal function no matter the cold that could be out side.