Biotechnology Research Institute, National Research Council Canada, 6100 Royalmount Ave., Montreal, QC, H4P 2R2, Canada.
Biodegradation. 2012 Apr;23(2):287-95. doi: 10.1007/s10532-011-9508-7. Epub 2011 Sep 1.
2,4-Dinitroanisole (DNAN) is a low sensitive melt-cast chemical being tested by the Military Industry as a replacement for 2,4,6-trinitrotoluene (TNT) in explosive formulations. Little is known about the fate of DNAN and its transformation products in the natural environment. Here we report aerobic biotransformation of DNAN in artificially contaminated soil microcosms. DNAN was completely transformed in 8 days in soil slurries supplemented with carbon and nitrogen sources. DNAN was completely transformed in 34 days in slurries supplemented with carbons alone and persisted in unamended microcosms. A strain of Bacillus (named 13G) that transformed DNAN by co-metabolism was isolated from the soil. HPLC and LC-MS analyses of cell-free and resting cell assays of Bacillus 13G with DNAN showed the formation of 2-amino-4-nitroanisole as the major end-product via the intermediary formation of the arylnitroso (ArNO) and arylhydroxylamino (ArNHOH) derivatives, indicating regioselective reduction of the ortho-nitro group. A series of secondary reactions involving ArNO and ArNHOH gave the corresponding azoxy- and azo-dimers. Acetylated and demethylated products were identified. Overall, this paper provides the evidence of fast DNAN transformation by the indigenous microbial populations of an amended soil with no history of contamination with explosives and a first insight into the aerobic metabolism of DNAN by the soil isolate Bacillus 13G.
2,4-二硝基苯甲醚（DNAN）是一种低敏感度的熔铸化学品，正被军工行业测试，以替代爆炸物配方中的 2,4,6-三硝基甲苯（TNT）。关于 DNAN 及其在自然环境中的转化产物的命运，人们知之甚少。在这里，我们报告了在人为污染的土壤微宇宙中 DNAN 的好氧生物转化。在补充了碳源和氮源的土壤悬浮液中，DNAN 在 8 天内完全转化；在单独补充碳源的悬浮液中，DNAN 在 34 天内完全转化，并在未改良的微宇宙中得以维持。从土壤中分离到一株通过共代谢转化 DNAN 的芽孢杆菌（命名为 13G）。通过高效液相色谱（HPLC）和 LC-MS 分析，发现 Bacillus 13G 细胞游离和静止细胞试验中，DNAN 形成了 2-氨基-4-硝基苯甲醚，这是主要的终产物，其通过芳基亚硝（ArNO）和芳基羟胺（ArNHOH）衍生物的中间形成，表明邻硝基基团的选择性还原。一系列涉及 ArNO 和 ArNHOH 的次级反应生成了相应的偶氮氧基和偶氮二聚体。鉴定出乙酰化和脱甲基产物。总的来说，本文提供了证据表明，在没有爆炸物污染历史的土壤中，土著微生物种群可以快速转化 DNAN，并且首次深入了解了土壤分离菌 Bacillus 13G 对 DNAN 的好氧代谢。
