Basic Studies of Determination of Diarrhetic Shellfish Poison by Using Tetrahymena pyriformis

Abstract

Basic investigations for the determination of Diarrhetic Shellfish Poison (DSP) were carried out with Tetrahymena pyriformis in place of the mouse lethal assay, and the following findings were obtained.
1. The growth of T. pyriformis was inhibited in proportion to the toxicity.
2. The growth inhibition of T. pyriformis increased with the progress of purification of the DSP fractions.
3. Heavy metals, pesticides, and PCBs in the hepatopancreas of scallops were effectively removed during DSP extraction. Therefore, DSP is responsible for the growth inhibition of T. pyriformis.
4. The 50% growth-inhibition value of T. pyriformis by DSP fractions was found to be equivalent to 0.5 Mouse Unit (0.05MU/ml medium) with satisfactory reproducibility.