摘要：Resistance of some chlorella in "algae water" against some heavy metals was examined. Cultivation of planktonic alga, chlorella, in heavily polluted river water in Nagoya city resulted in the increase of chlorella cells to 105-106/ml and water containing amount of chlorella is designated in this paper as "algae water." Addition of heavy metals to such a water hardly affected the live chlorella, up to 2 ppm of Cu2+ (as CuSO4) or 3 ppm each of Ni2+ (as NiSO4), Zn2+ (as ZnSO4), and Cr6+ (as K2CrO4), at pH 6-9. After several days, the amount of the dissolved metals present was 0.3-0.8 ppm of copper, and 0.8-2.0 ppm each of nickel, zinc, and chromium. These values of copper and zinc were higher than their theoretical solubility in water. The chlorella cells collected by centrifugation from the algae water after 1 week in such a water added with 20mg/liter of Cu2+ or 10mg/liter of Ni2+, Zn2+, or Cr6+, proliferated when cultured again in polluted river water. The polluted river water used for the experiments showed the values of ca. 30 ppm COD, ca. 50 ppm BOD, and no dissolved oxygen. From these results, it was considered that the toxicity of these heavy metals for the alga was buffered by the components in the heavily polluted water or in the algae water.
