Team:Jilin China/BACKGROUND

In the past few years, algal bloom caused by eutrophication has widely spread across the world and the situation became even worse after climate warming. It is reported that the algal bloom is taking place almost every main water globally, including Lake Victoria in Africa, Baltic, Lake Erie, Great Lakes and Ouji seeking Avon in Florida. The problem is that the algal can release a series of poisonous toxin called cyanotoxin, leading to serious diseases although they are not parasitic as other pathogenic bacteria.

And the microcystin is the most common one in these toxin which is very toxic and predominant. MC is a kind of intracellular toxin, released after the algal cells break down. It can do great damage to liver in the way of teratogenic, carcinogenic, mutagenic. In addition, MC is 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. In fact, some residues of MC can still be detected after processing of water plant chemically and physically. There is no doubt that an efficient method to deal with water polluted by MC is in urgent need. And that is exactly what our group would try to devote ourselves in.

After several days’discussion and skipping of many references,we were glad to find that in nature there are several germs can degrade MC efficiently, such as Sphingomonas, P seudomonas and Burkholderia. Further exploring these germs, we found that their ability to degrade MC is originated from several hydrolases(MlrA、MlrB and MlrC). These enzymes inspirited us a lot and finally our group decided to construct a genetically engineered bacteria based on these special enzymes,which can express these hydrolases efficiently to solve this kind of water pollution. And our work begins!