Hydrolytic enzymes which act on low pH are called as : -

Lysosomes contain many hydrolytic enzymes, such as lipases, proteases, carbohydrases and nucleases.
These enzymes work best at an acidic pH (about 4.5–5) maintained inside the lysosome, so they are called acid hydrolases.
Protease and amylase are particular types of hydrolytic enzyme, not the general name; peroxidase is an oxidoreductase.
So hydrolytic enzymes acting at low pH are called hydrolases (acid hydrolases).