Department of Microbiology, Oregon State University, Corvallis, OR, USA.
FEMS Microbiol Lett. 2014 Jan;350(1):34-41. doi: 10.1111/1574-6968.12316. Epub 2013 Nov 19.
The ability of ruminal microorganisms to degrade octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (high melting explosive, HMX) as consortia from whole rumen fluid (WRF), and individually as 23 commercially available ruminal strains, was compared under anaerobic conditions. Compound degradation was monitored by high-performance liquid chromatography, followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) for delineation of the metabolic pathway. In WRF, 30 μM HMX was degraded to 5 μM HMX within 24 h. Metabolites consistent with m/z 149, 193 and 229 were present throughout the incubation period. We propose that peaks with an m/z of 149 and 193 are arrived at through reduction of HMX to nitroso or hydroxylamino intermediates, then direct enzymatic ring cleavage to produce these HMX derivatives. Possible structures of m/z 229 are still being investigated and require further LC-MS/MS analysis. None of the 23 ruminal strains tested were able to degrade HMX as a pure culture when grown in either a low carbon or low nitrogen basal medium over 120 h. We conclude that microorganisms from the rumen, while sometimes capable as individuals in the bioremediation of other explosives, excel as a community in the case of HMX breakdown.
研究人员比较了从整个瘤胃液（WRF）中提取的瘤胃微生物群落和 23 种市售瘤胃菌株单独作为厌氧条件下的联合体，以评估其降解八氢-1,3,5,7-四硝基-1,3,5,7-四嗪（高熔点爆炸物，HMX）的能力。采用高效液相色谱法监测化合物降解情况，然后采用液相色谱-串联质谱法（LC-MS/MS）确定代谢途径。在 WRF 中，30 μM 的 HMX 在 24 小时内降解为 5 μM 的 HMX。在整个孵育过程中都存在与 m/z 149、193 和 229 一致的代谢物。我们提出，m/z 149 和 193 的峰是通过将 HMX 还原为亚硝基或羟氨基中间体，然后直接酶促环裂解产生这些 HMX 衍生物而形成的。m/z 229 的可能结构仍在研究中，需要进一步的 LC-MS/MS 分析。在低碳或低碳氮基础培养基中培养的 23 种瘤胃菌株在 120 小时内均不能作为纯培养物降解 HMX。我们得出结论，虽然微生物在其他爆炸物的生物修复中有时能够单独作为个体发挥作用，但在 HMX 分解方面，它们作为一个群落表现出色。
