球形红细菌降解RDX的动力学及其机理研究

Study on Degradation Kinetics and Mechanism of Explosive Hexahydro-1,3,5-trinitro-1,3,5-triazine(RDX)by Rhodobacter Sphaeroides

为了探索球形红细菌对黑索今（RDX）的降解动力学及机理,研究了该菌株生长与降解RDX 的关系,并对降解的动力学方程进行了拟合分析.采用气相色谱-质谱联用仪（GC-MS）分析了该菌株降解RDX 的中间代谢产物,并推测了其可能的降解途径.结果表明,RDX 质量浓度为2.5～30mg/L 时,该菌株对RDX 的降解符合一级动力学方程.培养4d时,用GC-MS检测到两种中间产物：六氢-1-亚硝基-3,5-二硝基-1,3,5-三嗪（MNX）和次甲基二硝胺（MEDINA）,其母离子的质荷比（m/z）分别为207和135,其可能的降解途径为：RDX 首先还原为MNX,再进行一系列还原反应生成产物MEDINA,最终降解为小分子物质,并认为硝基还原酶为该降解过程中的重要酶.

To explore the degradation kinetics and mechanism of explosive hexahydro-1,3,5-trinitro-1,3,5-triazine(RDX)by Rhodobacter sphaeroides,the relationship between the growth of Rhodobacter sphaeroides and RDX degradation was studied,and the fitting analysis of the degradation kinetic equation of RDX was performed.The intermediates of RDX metabolized by the strain were analyzed by gas chromatograph-mass spectrometer(GC-MS),and the possible pathway of RDX degradation was deduced.The results show that the RDX degradation by the strain is in accordance with the first-order kinetic model for RDX with initial mass concentration of 2.5-30mg/L.Cultivating for 4d,two intermediates hexahydro-1-nitroso-3,5-dinitro-1,3,5-triazine(MNX)and methylenedinitramine(MEDINA)were detected by GC-MS,and the ratios of mass to charge(m/z)of its parention were 207 and 135,respectively.The possible degradation pathway is that RDX is first reduced to MNX and the latter undergoes further reduction to finally produce MEDINA,which was finally degraded to smaller molecular compounds,considering that nitro reductase is an important enzyme in the degradation process.