Department of Civil and Environmental Engineering, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea.
Department of Civil and Environmental Engineering, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea.
J Hazard Mater. 2014 Jun 15;274:24-31. doi: 10.1016/j.jhazmat.2014.04.002. Epub 2014 Apr 13.
The potential of riboflavin for the reductive degradation of a cyclic nitramine, hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), was investigated in the presence of lepidocrocite and/or Shewanella putrefaciens CN32. RDX reduction by CN32 alone or CN32 with lepidocrocite was insignificant, while 110 μM RDX was completely reduced by CN32 with riboflavin in 78 h. The transformation products identified included nitroso metabolites, formaldehyde, and ammonium, indicating the ring cleavage of RDX. UV and visible light analysis revealed that riboflavin was microbially reduced by CN32, and that the reduced riboflavin was linked to the complete degradation of RDX. In the presence of both CN32 and lepidocrocite (γ-FeOOH), 100 μM-riboflavin increased the rate and extent of Fe(II) production as well as RDX reduction. An abiotic study also showed that Fe(II)-riboflavin complex, and Fe(II) adsorbed on lepidocrocite, reduced RDX by 48% and 21%, respectively. The findings in this study suggest that riboflavin-mediated RDX degradation pathways in subsurface environments are diverse and complex. However, riboflavin, either from bacteria or exogenous sources, can significantly increase RDX degradation. This will provide a sustainable clean-up option for explosive-contaminated subsurface environments.
核黄素在针铁矿和/或腐败希瓦氏菌 CN32 存在下还原降解六氢-1,3,5-三硝基-1,3,5-三嗪（RDX）的潜力。单独使用 CN32 或 CN32 与针铁矿还原 RDX 的作用不明显，而在有核黄素存在的情况下，110 μM 的 RDX 在 78 h 内被完全还原。鉴定出的转化产物包括亚硝基代谢物、甲醛和铵，表明 RDX 的环断裂。UV 和可见光分析表明，核黄素被 CN32 微生物还原，而还原的核黄素与 RDX 的完全降解有关。在 CN32 和针铁矿（γ-FeOOH）的共同存在下，100 μM-核黄素增加了 Fe(II)生成和 RDX 还原的速率和程度。一项非生物研究还表明，Fe(II)-核黄素络合物和针铁矿上吸附的 Fe(II)分别将 RDX 还原了 48%和 21%。本研究的结果表明，地下环境中核黄素介导的 RDX 降解途径是多样且复杂的。然而，无论是来自细菌还是外源的核黄素都可以显著增加 RDX 的降解。这将为受爆炸物污染的地下环境提供一种可持续的清理选择。
