DDT: Inhibition of Sodium Chloride Tolerance by the Blue-Green Alga Anacystis nidulans

Anacystis nidulans, a freshwater blue-green alga, has been found to tolerate sodium chloride (1 percent by weight) and DDT [1,1,1-trichloro-2,2-bis-(p-chlorophenyl)ethane] (800 parts per billion) separately, but growth was inhibited in the presence of both compounds. This inhibition was reversed by an increased calcium concentration. It is possible that inhibition of (Na$^{+}$,K$^{+}$)-activated adenosine triphosphatase) by DDT causes this species to lose the ability to tolerate sodium chloride.