高效菌株S对TNT的降解条件和机理初探

Study on the Conditions of TNT Biodegradation by Strain S and Preliminaryexploration of the Biodegradation Mechanism

确立了筛选菌株S对TNT的降解条件并初步探讨了TNT的降解机理。研究表明,葡萄糖的加入显著促进了TNT的生物降解,培养16h后100mg/L的TNT去除率达100%;但不加入葡萄糖时TNT仍有12%的去除,S菌也有微量生长。硝酸钾的加入同样促进了TNT的完全降解,而不加入硝酸钾时TNT有80%的去除。TNT浓度的增加并没有影响其去除效果,高达200 mg/L的TNT仍可完全降解。TNT的降解过程包括TNT生物转化为缩合产物A和A物质的开环分解。生物催化体系中硝基还原酶、甲苯双加氧酶和邻苯二酚双加氧酶的检出为这一降解途径的存在提供了有力的酶学支持。

The conditions and preliminary mechanism of TNT biodegradation by strain S was investigated.The results showed that glucose addition greatly enhances the biodegradation of TNT by strain S,and the removal efficiency of TNT reaches 100%after 16h culture;while the removal efficiency of TNT is only 12%when no glucose addition,leading to S growth slightly.KNO_3 addition also promotes TNT biodegradation and 100%TNT removal is attained,more than the 80%removal when no KNO_3 addition.Increase in TNT concentration has no evident adverse effect on its degradation,the strain S can completely biodegrade TNT even at 200 mg/L.The biodegradation of TNT involves that TNT was transformed into condensation product A and then A was degraded through ring cleavage. The existence of nitroreductase,toluene dioxygenase,catchpoll dioxygenase in the S biological catalyst system supplies enzyme basis for TNT degradation.