Fixation of CO2 and incorporation of thymidine under heavy metal stress inClosterium moniliferum

The unicellular green algaClosterium moniliferum was sensitive to the action of divalent Ni, Cu, Hg and Cd chlorides both in CO₂ fixation and in thymidine incorporation into DNA. At 0.08 ppm, Cd²⁺ was the most potent inhibitor (86 % inhibition of both processes), followed by Hg²⁺ and Cu²⁺, and finally by Ni²⁺, thymidine incorporation being generally more affected than CO₂ fixation.