The most thoroughly studied enzymes from earthworms are
proteases that are secreted by alimentary tract of earthworm [13].
For example, an earthworm, Lumbricus rubellus, produces
alkaline serine proteases that show higher activity and stability
than trypsins. These enzymes are stable at temperature below
60uC over a wide range of pH 2–11, and are strongly resistant to
organic solvents and detergents. Moreover, they retain full activity
for long years at room temperature. They act on various proteins,
such as elastin as well as fibrin, and some peptides, such as b-