Copper ion could rescue the growth inhibition of deinococcus radiodurans by cadmium ion

Deinococcus radiodurans have different phenotypes with different metals. It is not sensitive to Cu²⁺, while it is sensitive to Cd²⁺. When D. radiodurans was treated with Cd²⁺ alone, the inhibition of Cd²⁺ on the bacterium is remarkable. When D. radiodurans was cultured with 10 μL of 10 mmol·L^-1 Cd²⁺, then the addition of 10 μL of 10 mmol·L^-1 Cu²⁺ into the culture led to a significant antagonistic effect. The addition of copper (10 mmol·L^-1, 10 μL) resulted in the decrease of inhibition zone (about 24%). These results suggest that Cu²⁺ has obvious antagonistic effect on the toxic Cd²⁺ during the culture of D. radiodurans. The result provides theoretical support for detoxify heavy metal Cd by low toxicity metal Cu. (authors)