Agarase (, AgaA, AgaB, endo-beta-agarase, agarose 3-glycanohydrolase) is an enzyme with system name agarose 4-glycanohydrolase. It found in agarolytic bacteria and is the first enzyme in the agar catabolic pathway. It is responsible for allowing them to use agar as their primary source of Carbon and enables their ability to thrive in the ocean.