球形红细菌降解2,4-二硝基甲苯的途径及酶学性质  

Degradation Pathway and Properties of Enzyme of 2,4-Dinitrotoluene by Rhodobacter Sphaeroides

作　　者：白红娟 王寿艳 梁芳楠 赵婷婷 康鹏洲 

机构地区：[1]中北大学环境与安全工程学院,山西太原030051

出　　处：《火炸药学报》2017年第5期82-87,共6页Chinese Journal of Explosives & Propellants

基　　金：山西省回国留学人员科研资助项目(No.2016-084)

摘　　要：采用气相色谱-质谱联用仪(GC-MS)分析了球形红细菌降解2,4-二硝基甲苯(2,4-DNT)的中间代谢产物,分析了可能的降解途径,讨论了培养基中2,4-DNT的初始质量浓度、溶液pH值及反应温度对3种酶的酶比活力影响。结果表明,当2,4-DNT的初始质量浓度为40 mg/L时,培养72h后,可以检测到5种物质:2,4-二硝基甲苯、4-氨基-2硝基甲苯、2-氨基-4硝基甲苯、4-硝基-1,2-二(三甲基硅烷)苯、1,2,4-三(三甲基硅烷)苯,其可能的降解途径为2,4-DNT首先还原为4-氨基-2-硝基甲苯和2-氨基4-硝基甲苯,再进一步转化为4-硝基-1,2-羟基苯,然后氧化为1,2,4-三羟基苯,之后开环生成β-酮己二酸,最终降解为小分子物质。硝基还原酶、邻苯二酚2,3-双加氧酶和邻苯二酚1,2-双加氧酶的酶比活力最适宜温度分别为35、30、35℃,最适宜pH值分别为7.0、8.0、7.0,最适宜培养基初始2,4-DNT质量浓度均为40mg/L。The intermediates of 2,4-dinitrotoluene（2,4-DNT）metabolized by rhodobacter sphaeroides were analyzed by the gas chromatograph-mass spectrometer（GC-MS）,the possible degradation pathway was analyzed,and the effect of initial mass concentration of 2,4-DNT in culture medium,pH value of solution and reaction temperature on the enzyme specific activity of three kinds of enzymes was discussed.The results show that five intermediates including 2,4-dinitrotoluene,4-amino-2-nitrotoluene,2-amino-4-nitrotoluene,4-nitro-1,2-di（TMS）benzene and 1,2,4-tri（TMS）benzene were detected when initial mass concentration of 2,4-DNT is 40 mg/L after cultivating for 72 h.The possible degradation pathway is that 2,4-DNT is first reduced to 4-amino-2-nitrotoluene and 2-amino-4-nitrotoluene and further transformed into 4-nitro-1,2-hydroquinone,then is oxidized to 1,2,4-trihydroxybenzene,finally1,2,4-trihydroxybenzene ring is cleaved to formβ-ketoadipic acid,which was finally degraded to smaller molecular compounds.For enzyme specific actiyity of nitroreductase,catechol 2,3-dioxygenase and catechol 1,2-dioxygenase,the optimal temperature is 35,30 and 35℃,respectively,the optimal pH value is 7.0,8.0 and 7.0,respectively and the optimal initial mass concentration of 2,4-DNT in culture medium is 40 mg/L.

关 键 词：球形红细菌 2 4-二硝基甲苯 2 4-DNT 硝基还原酶 邻苯二酚1 2-双加氧酶 邻苯二酚2 3-双加氧酶 

分 类 号：TJ55[兵器科学与技术—军事化学与烟火技术] TQ464.8[化学工程—制药化工]