Department of Chemical and Environmental Engineering, University of Arizona, Tucson, Arizona, USA.
Center for Environmental Diagnostics and Bioremediation, University of West Florida, Pensacola, Florida, USA.
Biotechnol Bioeng. 2022 Sep;119(9):2437-2446. doi: 10.1002/bit.28160. Epub 2022 Jun 27.
Insensitive munitions compounds (IMCs), such as 2,4-dinitroanisole (DNAN) and 3-nitro-1,2,4-triazol-5-one (NTO), are replacing conventional explosives in munitions formulations. Manufacture and use of IMCs generate waste streams in manufacturing plants and load/assemble/pack facilities. There is a lack of practical experience in executing biodegradation strategies to treat IMCs waste streams. This study establishes a proof-of-concept that bacterial consortia can be designed to mineralize IMCs and co-occurring nitroaromatics in waste streams. First, DNAN, 4-nitroanisole (4-NA), and 4-chloronitrobenzene (4-CNB) in a synthetic DNAN-manufacturing waste stream were biodegraded using an aerobic fluidized-bed reactor (FBR) inoculated with Nocardioides sp. JS 1661 (DNAN degrader), Rhodococcus sp. JS 3073 (4-NA degrader), and Comamonadaceae sp. LW1 (4-CNB degrader). No biodegradation was detected when the FBR was operated under anoxic conditions. Second, DNAN and NTO were biodegraded in a synthetic load/assemble/pack waste stream during a sequential treatment comprising: (i) aerobic DNAN biodegradation in the FBR; (ii) anaerobic NTO biotransformation to 3-amino-1,2,4-triazol-5-one (ATO) by an NTO-respiring enrichment; and (iii) aerobic ATO mineralization by an ATO-oxidizing enrichment. Complete biodegradation relied on switching redox conditions. The results provide the basis for designing consortia to treat mixtures of IMCs and related waste products by incorporating microbes with the required catabolic capabilities.
钝感弹药化合物（IMCs），如 2,4-二硝基苯甲醚（DNAN）和 3-硝基-1,2,4-三唑-5-酮（NTO），正在替代弹药配方中的传统炸药。IMCs 在制造工厂和装载/组装/包装设施中产生废物流。在执行生物降解策略处理 IMCs 废物流方面，缺乏实际经验。本研究证明了细菌群落可以设计用于矿化 IMCs 和废物流中的共存硝基芳烃。首先，在有氧流化床反应器（FBR）中，用 Nocardioides sp. JS 1661（DNAN 降解菌）、Rhodococcus sp. JS 3073（4-NA 降解菌）和 Comamonadaceae sp. LW1（4-CNB 降解菌）接种，对合成 DNAN 制造废物流中的 DNAN、4-硝基苯甲醚（4-NA）和 4-氯硝基苯（4-CNB）进行生物降解。当 FBR 在缺氧条件下运行时，未检测到生物降解。其次，在一个包括以下连续处理步骤的合成装载/组装/包装废物流中，DNAN 和 NTO 被生物降解：（i）在 FBR 中进行有氧 DNAN 生物降解；（ii）通过 NTO 呼吸富集物将 NTO 生物转化为 3-氨基-1,2,4-三唑-5-酮（ATO）；（iii）通过 ATO 氧化富集物将 ATO 有氧矿化。完全生物降解依赖于切换氧化还原条件。这些结果为设计通过合并具有所需代谢能力的微生物来处理 IMCs 和相关废物混合物的群落提供了基础。
