Primary Studies On Toxin Production And Allelopathy Of Prorocentrum Lima

Prorocentrum lima, which was known to produce diarrhetic shellfish poisoning, was common marine benthic dinoflagellate. As a producing model of DSP toxin, it had got much attention.In order to learn the feature of DSP production, to elucidate the complicate mechanism of DSP biosynthesis and to understand the potential allelopathic effect of P. lima on other organism, production of DSP in different growth phases in P. lima and under different nutrients limited conditions was investigated by ELISA, meanwhile, the influence of the culture, cell-free filtrate and DSP extract from P. lima on three harmful bloom algae, Alexandrium tamarense, Chattonella marina and Prorocentrum donghaiese was studied.OA concentration per cell of P. lima was different in various growth phases. The peak of OA was in stationary phase, which was different significantly to that in mid-log phase (P<0.05). P. lima under N-,P-,Fe- limited conditions grew better than that of control, in contrast, OA concentrations were lower than that of control. In special, cell density, the concentration of chlorophyll a and OA per cell under N-limited conditions changed significantly compare with control. These suggested that the DSP synthesis in P. lima was related to the cell division, photosynthesis and environment stress.Growth of Alexandrium tamarense, Chattonella marina, Prorocentrum donghaiese and P. lima itself was restrained in different degree when co-cultured with each other. Growth of Prorocentrum donghaiese and Chattonella marina was inhibited when cultured in cell-free filtrate. The inhibition on Prorocentrum donghaiese was the most serious. DSP extract inhibited growth of the three harmful bloom algae seriously, while Chattonella marina was completely inhibited. The...