Bacterial Transformation of Paralytic Shellfish Toxins in Coral Reef Crabs and a Marine Snail

Abstract

Incubation of gonyautoxins with tissue extracts prepared from two species of crab, Atergatis ftoridus and Eriphia scabricula, and from the turban shell, Turbo argyrostoma, confirmed trans-formation of gonyautoxins to saxitoxin through reductive elimination of C-ll hydroxysulfate and N-1 hydroxyl moieties. The reaction did not take place under bacteriostatic condition, indicating that bacteria rather than tissue enzymes were responsible for the reduction. The bacterial role was further confirmed by the fact that Pseudomonas sp. and Vibrio sp. isolated from the viscera of the above animals similarly converted gonyautoxins into saxitoxin. The bioconversion ex-plained, at least partly, the discrepancy that saxitoxin and neosaxitoxin were predominant in the crabs and snails while their food alga, Jania sp., contained only gonyautoxin-I, -II, and -III. In-cubation with bacteria showed little effect on saxitoxin. © 1985, The Japanese Society of Fisheries Science. All rights reserved.