Regional variation in the production of enzymes in the digestive tract of Strongylocentrotus droehbachiensis (O.F. Mueller)
Though research has been done on the physiology of mature Strongylocentrotus droehbaehiensie (O.F. Muller), there has been little description of the sequence of enzymatic action on food in passege through the intestine or the relation of the siphon to digestion. This paper delineates the intestinal areas of production of sucrase, amylase, protease, and an enzme which removes the sulfate group from sulfonated sugars, sulfatase. The enzyme action is then related to the passage of food through the intestine. The presence of protease, sucrase, and amylase in s. droebachiensis has been known for a long time (Cohiem, 1901; Scott, 1901 as cited by Hymen, 1955; and Bertolini, 1930, 1932). Weese (1926) investigated the nature of two of these enzymes, amylase and proteasem, to find the optimum pH for their digestive action. The optimum pH for amylase he found to be 7.5. For protease, he conducted two separate tests. The first test was on egg albumin for which he found two optima, ph 2.4 and 5.2. The second test was on the digestion of gelatin, for which he found optima at 2.4 and 7.5. In the same publication Weese found the pH of the fluid in the digestive tract to be between 6 .2 and 7.5, and therefore not to be optimal for the digestion of albumen.