Zhao J-S, Paquet L, Halasz A, Hawari J
Biotechnology Research Institute, National Research Council of Canada, 6100 Royalmount Avenue, Montreal, Quebec, H4P 2R2, Canada.
Appl Microbiol Biotechnol. 2003 Dec;63(2):187-93. doi: 10.1007/s00253-003-1364-x. Epub 2003 Jun 24.
A fast hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX)-degrading [28.1 micromol h(-1) g (dry weight) cells(-1); biomass, 0.16 g (dry weight) cells(-1)] and strictly anaerobic bacterial strain, HAW-1, was isolated and identified as Clostridium bifermentans using a 16S-rRNA-based method. Based on initial rates, strain HAW-1 transformed RDX to hexahydro-1-nitroso-3,5-dinitro-1,3,5-triazine (MNX), hexahydro-1,3-dinitroso-5-nitro-1,3,5-triazine (DNX), and hexahydro-1,3,5-trinitroso-1,3,5-triazine (TNX) with yields of 56, 7.3 and 0.2%, respectively. Complete removal of RDX and its nitroso metabolites produced (%, of total C or N) methanol (MeOH, 23%), formaldehyde (HCHO, 7.4%), carbon dioxide (CO2, 3.0%) and nitrous oxide (N2O, 29.5%) as end products. Under the same conditions, strain HAW-1 transformed MNX separately at a rate of 16.9 micromol h(-1) g (dry weight) cells(-1) and produced DNX (25%) and TNX (0.4%) as transient products. Final MNX transformation products were (%, of total C or N) MeOH (21%), HCHO (2.9%), and N2O (17%). Likewise strain HAW-1 degraded TNX at a rate of 7.5 micromol h(-1) g (dry weight) cells(-1 )to MeOH and HCHO. Furthermore, removal of both RDX and MNX produced nitrite (NO2-) as a transient product, but the nitrite release rate from MNX was quicker than from RDX. Thus, the predominant pathway for RDX degradation is based on initial reduction to MNX followed by denitration and decomposition. The continued sequential reduction to DNX and TNX is only a minor route.
分离出一株快速降解六氢-1,3,5-三硝基-1,3,5-三嗪（RDX）的严格厌氧细菌菌株HAW-1，其降解速率为[28.1微摩尔·小时⁻¹·克（干重）细胞⁻¹]，生物量为0.16克（干重）细胞⁻¹，并通过基于16S-rRNA的方法鉴定为双发酵梭菌。根据初始速率，菌株HAW-1将RDX转化为六氢-1-亚硝基-3,5-二硝基-1,3,5-三嗪（MNX）、六氢-1,3-二亚硝基-5-硝基-1,3,5-三嗪（DNX）和六氢-1,3,5-三亚硝基-1,3,5-三嗪（TNX），产率分别为56%、7.3%和0.2%。RDX及其产生的亚硝基代谢产物的完全去除（占总碳或氮的百分比）产生甲醇（MeOH，23%）、甲醛（HCHO，7.4%）、二氧化碳（CO₂，3.0%）和一氧化二氮（N₂O，29.5%）作为终产物。在相同条件下，菌株HAW-1以16.9微摩尔·小时⁻¹·克（干重）细胞⁻¹的速率分别转化MNX，并产生DNX（25%）和TNX（0.4%）作为瞬时产物。MNX的最终转化产物为（占总碳或氮的百分比）MeOH（21%）、HCHO（2.9%）和N₂O（17%）。同样，菌株HAW-1以7.5微摩尔·小时⁻¹·克（干重）细胞⁻¹的速率将TNX降解为MeOH和HCHO。此外，RDX和MNX的去除均产生亚硝酸盐（NO₂⁻）作为瞬时产物，但MNX的亚硝酸盐释放速率比RDX快。因此，RDX降解的主要途径是先还原为MNX，然后进行脱硝和分解。持续依次还原为DNX和TNX只是一条次要途径。
