تعیین آستانه سمیت فلزات مس و روی در باکتری E. coli (حسگر زیستی))

Abstract
Soil contamination with heavy metals is a serious problem in all over the world. Soils are contaminated by many different sources of heavy metals. Currently different methods are used by researchers for identifying heavy metal contamination. Assessing soil metal toxicity with bacterial bioluminescence is one of the new techniques. In this study, different concentrations of zinc and copper (0, 5, 20, 120 300,755, 2000 mg/kg for Cu, 0, 10, 30, 70, 160 400, 1000, 3000 mg/kg for Zn in sulphate form) were applied to Lincoln soils, New Zealand, in two different sites. After one year, the total concentrations of copper and zinc were measured in soil samples. Bacterial bioluminescence technique (Bioluminator) was used for determination of toxicity threshold of Cu and Zn for E.coli.. The results showed that the bacterial bioluminescence decreased by increasing copper and zinc concentrations. We also found that the bacterial bioluminescence decreased, 50% compared to control plot at 450 and 65 mg/kg Cu and Zn concentrations respectively. The correlation between bioluminescence and total metal concentration showed that zinc was more toxic to E. coli than copper.

Keywords: Bioluminescence, Heavy metals, Zinc, Copper. E. coli