Biotechnology Research Institute, National Research Council Canada, Montréal, Québec, Canada.
J Appl Microbiol. 2009 Dec 1;107(6):1799-808. doi: 10.1111/j.1365-2672.2009.04366.x. Epub 2009 May 5.
To study the impact of added 2,4-dinitrotoluene (DNT) on the anaerobic bacterial community in marine sediment collected from an unexploded ordnance dumping site in Halifax Harbour.
Marine sediment was spiked with 2,4-DNT and incubated under anaerobic conditions in the presence and absence of lactate. Indigenous bacteria in the sediment removed 2,4-DNT with subsequent formation of its mono- and diamino-derivatives under both conditions. PCR-DGGE and nucleotide sequencing were used to monitor the change in the bacterial population in sediment caused by the presence of 2,4-DNT. The results showed that denaturing gradient gel electrophoresis banding patterns of sediment microcosms treated with 2,4-DNT were different from controls that did not receive 2,4-DNT. Bacteroidetes, Firmicutes and delta-Proteobacteria were present in sediment incubated in the absence of 2,4-DNT. However, several gamma-Proteobacteria became dominant in sediment in the presence of 2,4-DNT, two of which were 99% similar to Shewanella canadensis and Shewanella sediminis. In the presence of both 2,4-DNT and lactate, two additional delta-Proteobacteria were enriched, one closely related (98% similarity) to Desulfofrigus fragile and the other affiliated (96% similarity) to Desulfovibrio sp. In contrast, none of the above four Proteobacteria were enriched in sediment incubated with lactate alone.
Presence of 2,4-DNT led to a significant change in bacterial population of marine sediment with the enrichment of several gamma- and delta-Proteobacteria.
Our results provided the first evidence on the impact of the pollutant 2,4-DNT on the indigenous bacterial community in marine sediment, and provided an insight into the composition of bacterial community that degrade 2,4-DNT.
研究添加 2,4-二硝基甲苯（DNT）对哈利法克斯港未爆炸弹药倾倒场采集的海洋沉积物中厌氧细菌群落的影响。
将海洋沉积物与 2,4-DNT 混合，并在存在和不存在乳酸盐的情况下在厌氧条件下孵育。沉积物中的土著细菌在两种条件下都去除了 2,4-DNT，随后形成了其单氨基和二氨基衍生物。PCR-DGGE 和核苷酸测序用于监测 2,4-DNT 存在引起的沉积物中细菌种群的变化。结果表明，用 2,4-DNT 处理的沉积物微宇宙的变性梯度凝胶电泳带型与未接受 2,4-DNT 的对照不同。在不存在 2,4-DNT 的情况下，在沉积物中培养时存在拟杆菌门、厚壁菌门和δ-变形菌门。然而，在存在 2,4-DNT 的情况下，几种γ-变形菌门成为优势菌，其中两种与加拿大希瓦氏菌和 Sediminis 希瓦氏菌相似度达到 99%。在 2,4-DNT 和乳酸盐的存在下，两种额外的δ-变形菌门被富集，一种与脆弱脱硫弧菌密切相关（相似度为 98%），另一种与脱硫弧菌属相关（相似度为 96%）。相比之下，在单独用乳酸盐孵育的沉积物中，没有上述四种变形菌门被富集。
2,4-DNT 的存在导致海洋沉积物中细菌种群发生显著变化，几种γ-和δ-变形菌门得到富集。
我们的研究结果首次提供了关于污染物 2,4-DNT 对海洋沉积物中土著细菌群落影响的证据，并深入了解了降解 2,4-DNT 的细菌群落的组成。
