New Inhibitor for Mating Reaction of Alexandrium catenella Produced by Marine Alteromomas sp

Abstract

Marine bacteria were screened for mating inhibitor on a toxic dinoflagellate Alexandrium catenella using a hypnozygote (cyst) formation bioassay. A highly active bacterium was cultured, and the cell extract was fractionated by means of heat treatment, DEAE-cellulose chromatography, and gel filtration to obtain a partially purified inhibitor (MIMB). MIMB was characterized as a protein with a molecular weight of more than 700 kDa. MIMB blocked the sexually attaching stage of the mating reaction in A. catenella at an extremely low concentration of 7 ugltni. © 1993, The Japanese Society of Fisheries Science. All rights reserved.