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!
References:
[1]M icrobial degradation of m icrocystins in water environm ent: A review. KONG Yun, XU Xiang-yang, ZHU L iang, XU Jing, LIN H a-i zhuan (Departm ent of Environmental Engineering,Zhejiang University, H angzhou 310058, China ). -Chin. J. App l. E col. , 2011, 22( 6) : 1646- 1652
[2]Effects of Cyanobacteria Pollution and ControlMethods：ZHOU Guo-ding(Changzhou E cotechnology App lication R esearch Instn teti, Changzhou, J iang su 213022, China )
[3]Advances in Pollution of Cyanobacterial Blooms-Producing Microcystins and their Ecotoxicological Effects on Aquatic Organisms：Jiang Jinlin1 Song Rui1 Ren Jinghua2 Wang Xiaorong1Yang Liuyan1 (1. State Key Laboratory of Pollution Control and Resources Reuse，School of Environment，Nanjng University，Nanjing 210093，China; 2. College of Resource and Environment，Shaanxi University of Science and Technology，Xi′an 712081，China)
[4] Ho L, Meyn T, Keegan A,etal. Bacterial degradation of microcystin toxins within a biologically active sand filter. Water Research, 2006, 40: 768- 774
[ 5] Bourne DG, B lakeley RL, Riddles P, etal. Biodegradation of the cyanobacterial toxin microcystin LR innatural water and biologically active slow sand filters. Water Research, 2006, 40: 1294- 1302
[6] ChenW, Song LR, Peng L, etal. Reduction in microcystin concentrations in large and shallow lakes: Water and sediment interface contributions. Water Research,
2008, 42: 763- 773
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