PHOTOLYSIS OF ALDRIN AND DIELDRIN IN A PHYTOPLANKTON

Residues of aldrin and dieldrin in the green alga, Euglena gracilis (chloroflagellate), in the presence of fluorescent, blue or red light, are converted to photoaldrin and photodieldrin, respectively. This photoisomerization does not occur in the dark or in the presence of green light. Similar exposure of Tetrahymena or Paramecium to room light does not show any photolysis indicating that the green pigment may be responsible for this photolysis. The extracted chlorophyll is capable of carrying out this photoisomerization, and this photolysis can be inhibited by the photosynthesis inhibitor, monuron. That this phytoplankton can perform photolysis of these aquatic pollutants indicates the potential of phytoplanktons in altering the chemical and biological characteristics of hazardous chemicals present in surface waters.