Abstract
The digestive gland and crop of the Roman snail, Helix pomatia, appear to contain large amounts of beta-glucuronidase. This enzyme has an optimum pH of 4.2 when acting on quinolyl-8-glucuronide as a substrate. The 8-hydroxyquinoline formed by the enzymic hydrolysis of the substrate was estimated by coupling it with diazotized sulfanilic acid. The concentration of the azo dye produced was measured spectrophotometrically. The beta-glucuronidase of the Roman snail is related to, and probably identical with, the enzyme known to exist in the digestive gland of certain marine molluscs and the crop fluid of locusts. The digestive glands of Limnea stagnalis, Planorbis corneus and Anodonta cygnea contain only small amounts of glucuronidase compared with H. pomatia and H. aspersa.