ON THE ORIGIN OF THE CELLULASE AND CHITINASE OF HELIX POMATIA

Abstract

Specimens of the snail Helix pomatia were fed for 2 days at room temperature after emergence from hibernation at 4° and total soluble protein, total units of cellulase activity towards carboxymethyl cellulose, and total units of chitinase activity towards glycol chitin were determined in the digestive juice, hepatopancreas, and intestinal wall. Comparisons of these values with those for hibernating snails showed that emergence from hibernation and resumption of feeding was accompanied by a substantial decrease in soluble protein in the hepatopancreas, and a substantial increase in soluble protein cellulase and chitinase in the digestive juice. Cellulase and chitinase in the digestive juice showed little change in specific activity and were present in approximately the same ratio as in the hepatopancreas and intestinal wall. The volume of digestive juice in snails which had been deprived of food after a brief posthibernation feeding increased significantly with starvation times up to at least 5 days but the concentration of protein, cellulase, chitinase, and helicorubin showed no significant change. Plate counts for viable bacteria in the hepatopancreas indicated that the hepatopancreas was virtually sterile. The difficulty of reconciling these findings with the hypothesis of a bacterial origin for the cellulase and chitinase in snail digestive juice is discussed.