Copper Susceptibility of Three Growth Stages of the Green Alga 'Haematococcus'

摘要

Three growth stages of the green alga, Haematococcus, were examined to determine their survival and recovery following a 12-hour exposure to copper. Copper uptake of flagellate cells, palmelloid cells, and akinetes was measured by atomic absorption spectrophotometry, and cell counts were used to determine the numbers of surviving cells as well as growth rates following exposure to copper. The location of amassed copper was determined with cytochemical methods developed for light microscopy and transmission electron microscopy. Flagellate cells accumulated less copper per cell than palmelloid cells or akinetes. When compared to the other growth stages on a volume basis, however, flagellate cells were found to have accumulated significantly more copper. This may account for the greater sensitivity of flagellate cells to low concentrations of copper. Cellular sites external to the plasma membrane appear to act as nontoxic areas that may sequester copper ions and prevent them from reaching more sensitive cytoplasmic sites.