多氯联苯的生物降解研究

PCBs的氧化反应是通过加氧酶的作用,分子氧在PCBs的无氯环或带较少氯原子环的2,3位发生反应,形成顺二氢醇混合物PCBs的完全降解需要不同系列微生物的协同作用,这些微生物可以利用不同的PCBs降解产物。另外氯原子的位置和数量也影响着微生物氧化攻击的效率。UNTERMAN等假设出A.eutrophus sp.,P. putida和Corynebacterium sp.对于PCBs的氧化机制。Alcalegenes eutrophus和P.putida sp.等微生物是对多氯联苯2,3-位的亲核攻击发生作用。对于Corynebacteriun降解混合物的反应则是对污染物3,4位的亲核攻击。

Study on Biodegradation of Polychlorinated Biphenyls

Molecular oxygen was introduced at 2,3 position of nonchlorinated or lesser chlorinated ring of PCB to form cis-dihydrodiol compounds by action of oxygenase. The complete degradation of PCBs requires various microbial strains with specific congener preference. In addition,the position and number of chlorines on molecule can affect the rate of the first oxygenase attack. UNTERMAN proposed a mechanism for oxidation of PCBs by A. eutrophus sp,P. putida and Corynebacterium sp. Alcalegenes eutrophus and P. putida sp strains degraded tetrachlorobiphenyl via 2,3-attack while Corynebacterium degraded the compound via 3,4-attack.