Microcystin-LR (MC-LR) is a naturally occurring toxin released after the algal cells break down, which can do great damage to liver,very stable and in some extent is very resistant to high temperature and pH change, so it brings the water purification into a very embarrassing situation.
Mlr promoter is able to detect whether water containing microcystin LR and start to expressthe GFP-mlrA fusion protein. GFP can emit green fluorescence, very simple and very sensitive to tell us the water contains toxic microcystin LR. MlrA can directly degrade microcystin LRand eliminate its toxicity, eliminate the toxins in water pollution.
The mlr promoter-GFP-mlrA was be cloned into the E. coli-L. lactis shuttle expression vector pMG36e, so it can be able to express in E. coli and Lactococcus lactis, which Can easily be constructed in the laboratory, at the same time to avoid secondary pollution in the natural environment of E. coli.