The interaction of chronic copper toxicity with nutrient limitation in two chlorophytes in batch culture

Abstract

The interaction of N- and P-limitation with sublethal Cu toxicity in the two chlorophytes, Chlamydomonas geitleri Ettl and Chlorella vulgaris Beyerinck, is described. Batch culture experiments were conducted in which either N or P limited final yield. The sublethal effects of Cu toxicity included decreased growth rate and final yield and increased cellular content of Cu and P. Final yield and growth rate were the most sensitive indicators of toxicity in P-limited and N-limited cultures respectively. Both algae were more sensitive to Cu toxicity in batch cultures under P-limitation than under N-limitation. This suggests a need for careful consideration of the parameters used to measure toxicity and of the nutrient limiting the final yield of batch cultures in metal toxicity studies.