Study On Hemolysin And Genes Of Bio-synthesizing The Toxin Of Phaeocystis Globosa

Phaeocystis globosa have recently induced harmful algal blooms (HABs) in our country, which occasionally produce hemolysin. The algae that produce hemolysin may be an allelopathic behavior when their growth is limited by completion from other phytoplankton. The factors are profound that effect the bio-synthesis of Phaeocystis globosa hemolysin.To obtain the maximum rate of extracting toxin, the conditions were optimized of breaking Phaeocystis globosa cells' walls with ultrasonic. The optimum conditions are individually 3, 2 and 1 liter(s) P. globosa cultures of logarithmic, stationary and senescent phase under 600W power, 4℃ within 30 minutes.The activity of hemolysis from P. globosa cells in culture is the same with that from P. globosa cells in field. The value of its activity is about 21HU/L. There are at least 4 components in the hemolytic toxin from P. globosa cultures in laboratory that is slightly different from that of the wild P. globosa cells.The hemolysin breaks red blood cells (RBCs) through its hydrophobe group linking to the surface of RBCs. The varied temperate, concentration of H⁺ and divalent cations have different effects on the hemolytic activity of the toxin. The higher temperate, the stronger hemolytic activity, and the optimum temperate is 37℃. As for the different of H⁺ concentration, the strongest hemolytic activity was gotten in pH7. In different treatment of divalent cations solutions, Hg²⁺ has the significant inhibition and EDTA can nearly eliminate the inhibition. The other divalent cations have also inhibition of hemolytic activity of hemolysin from P. globosa to some extent. Hence, the inhibition of the divalent cations may be that they close the holes induced by hemolysin. The different membrane lipids also inhibit the hemolytic activity of hemolysin to different degrees, except for phosphatidic acid. This result indicates that the hemolysin has no special receptor in the surface of RBCs.Additionally, the hemolysin can kill the Prorocentum donghaiense,...