Influence of Lipid Composition in Amplifying or Ameliorating Toxicant Effects on Phytoplankton.

摘要

These studies demonstrate that lipid composition of both diatom cultures and natural phytoplankton assemblages varies greatly on a diel cycle. Exposure experiments on both cultures of diatoms and natural assemblages demonstrated that different results could be obtained by merely changing the timing of the initial exposure. Cells that were undergoing changes in lipid composition appeared to be most susceptible to chlorinated hydrocarbons, especially when periods of polar lipid synthesis immediately followed the exposure. However, as a rule, the chlorinated benzenes at concentrations approaching water solubility, did not appear to have significant long term effects on the diatom cultures studied. Short-term changes were observed, but recovery was also evident. The effect of timing of exposure suggests that standard toxicity tests should be conducted with extreme care since results may vary with the natural diel lipid cycle. Lipid composition, phytoplankton, toxicants, diatoms, light-cycle.