0000000000679146
AUTHOR
Malte Elbrächter
Bacteria of the Genus Roseobacter Associated with the Toxic Dinoflagellate Prorocentrum lima
The dinoflagellate Prorocentrum lima is known to produce diarrhetic shellfish poisons. However, it is yet unclear if the dinoflagellates themselves or the bacteria associated with them produce the toxins. Here we analyze the toxicity as well as the spectrum of bacteria in two cultures of P. lima, namely P. lima-SY and P. lima-ST, which initially derived from the same P. lima strain PL2V. Toxicity tests, applying the Artemia bioassay revealed in both cultures high levels of toxins. The bacteria, associated with the two cultures, were identified by PCR/nucleotide sequence analysis of the 16S rRNA gene. From cultures of P. lima-SY the dominant sequence was found to share a 93.7% similarity wit…
Changes of ICE protease activities caused by toxic supernatants of dinoflagellates (Prorocentrum species) from marine algal blooms
Summary Marine phytotoxins may become a major health problem for humans because of their ability to contaminate seafood and to cause shellfish poisoning. In this report, the cytotoxic effects and the effects on intracellular caspase activities of culture supernatants from different dinoflagellate Prorocentrum clones were determined. Among the clones tested, P. tepsium BAH ME-140 and P. lima BAH ME-130 K1 and K2 clones but not P. minimum and P. micans were found to be toxic on rat pheochromocytoma PC12 cells, mouse lymphoma L5178Y cells and rat primary neurons. A significant increase in the specific activities of caspase 1 (ICE), caspase 3 (CPP32) and caspase 6 (Mch2) to 149–167% was observe…