ACID-PHOSPHATASE IN THE PATHOGENIC AND NONPATHOGENIC HEMOFLAGELLATES,CRYPTOBIA SPP, OF FISHES

Acid phosphatase (ACP) was detected in whole-cell lysates, membrane-bo und and water-soluble fractions of Cryptobia salmositica (pathogenic a nd nonpathogenic vaccine strains), Cryptobia bullocki, and Cryptobia c atostomi using p-nitrophenylphosphate as the substrate. High activitie s were in acidic pH (3.0-5.5) and the optimal pH was 5.0. Highest ACP activity was in the membrane-bound fraction. The pathogenic strain of C. salmositica had significantly higher total ACP activity than the va ccine strain and the other 2 species. However, the activity in the pat hogenic C. salmositica decreased significantly with prolonged in vitro cultivation. The membrane-bound ACP of the pathogenic C. salmositica had highest resistance to the ACP inhibitor, sodium tartrate.