除草剂阿特拉津生物降解研究进展  

Advance on the Studies of Biodegradation of Herbicide Atrazine

作　　者：蔡宝立[1] 黄今勇[1] 

机构地区：[1]南开大学分子生物学研究所

出　　处：《生物工程进展》1999年第3期7-11,共5页Progress in Biotechnology

摘　　要：阿特拉津（Ａｔｒａｚｉｎｅ）又称氯乙异丙嗪［２－氯－４（乙基）－６－（异丙氨基）－１，３，５－三嗪］，商品名莠去津，是一种广泛使用的三嗪类除草剂，用于阔叶杂草和禾草的防除，如玉米、高梁、甘蔗和库区杂草等。阿特拉津虽然是一种低毒除草剂，但由于它被微生物矿化的过程十分缓慢，在土壤中的半存留期长达４—５７周，所以在施用过这种除草剂的土壤中以及地下水和表面水中，其浓度远远超过３ｐｐｂ的最大允许值，造成对环境的污染［１］。阿特拉津在世界范围内已经使用了近４０年，其在环境中的扩散引起广泛重视，因此研究这种化合物的生物降解机理十分必要。虽然自１９８２年以来先后在诺卡氏菌属（Ｎｏｃａｒｄｉａ）［２，３］、红球菌属（Ｒｈｏｄｏｃｏｃｕｓ）［４，５］、不动杆菌属（Ａｃｉｎｅｔｏｂａｃｔｅｒ）［６］、土壤杆菌属（Ａｇｒｏｂａｃｔｅｒｉｕｍ）［７］和假单胞菌属（Ｐｓｅｕｄｏｍｏｎａｓ）［１，８，９］等多个细菌属中分离到降解阿特拉津的菌株，但直到９０年代中期，对这一生物降解过程所涉及到的基因、酶和中间代谢物仍知之甚少。自１９９５年Ｗａｃｋｅｔ实验室从施用过阿特拉津的土壤中分离到假单胞菌ＡＤＰ菌株以后［１］，阿特拉津的生物降解机理研究?In soil, atrazine is primarilly degraded biologically.As candidates for use in biodegradation, a variety of pure microbial strains that degrade atrazine have been isolated and characterized. These include strains of Rhodococcus,Pseudomonas,Nocardia,Acinetobacter,Agrobacterium,Rhizobium,Ralstonia,Clavibacter, and Alcaligens. Most of our current understanding of the genes and enzymes involved in atrazine degradation derives from studies using Pseudomonas strain ADP, in which the first three enzymatic steps in atrazine degradation have been defined. The genes atzA,-B, and -C ,which encode these enzymes, have been cloned and sequenced. Atrazine chlorohydrolase (AtzA),hydroxyatrazing ethylaminohydrolase (AtzB), and N isopropylammelide isopropylaminohydrolase (AtzC) sequentially convert atrazine to cyanuric acid. Cyanuric acid and related compounds are catabolized by Pseudomonas sp. ADP to carbon dioxide and ammonia. The atzA,-B,and -C genes in Pseudomonas sp.strain ADP,have been located on a 96 kb self transmissible plasmid. These understanding can be used to enhance the use of genetic and protein engineering to biodegrade atrazine pollutant.

关 键 词：阿拉特津 除草剂 生物降解 氯水解酶 

分 类 号：S482.49[农业科学—农药学]