A fractured basalt aquifer at the Idaho National Engineering and Environmental Laboratory-Test Area North (INEEL-TAN) in southeast Idaho is the site of a nearly two-mile long trichloroethylene (TCE) contaminant plume. As part of an effort to evaluate the feasibility of applying bioremediation techniques at TAN, organisms potentially responsible for naturally attenuating or remediating the site were identified. Culture-based and molecular biology methods were used to investigate planktonic and attached anaerobic subsurface microbial communities. Many organisms were identified representing twenty-two different genera, ten by culture-based methods and twelve by direct identification using molecular biology methods. These results confirmed the presence of a diverse eubacteria community within this oligotrophic, but contaminated subsurface system. One of the identified organisms, Pantoea agglomerans, was capable of partially degrading 0.2 mM of PCE or 0.5 mM of TCE in about 7 days. Many attempts were made to achieve complete degradation of TCE by adjusting the medium. Although some increases in TCE degradation were observed, most of the increases were not significantly different from the baseline performance. We were unable to ascertain why only partial TCE degradation occurred.; Molecular biology techniques were used to observe changes in the microbial community during a field scale application of enhanced in situ bioremediation of a TCE contaminated groundwater plume located INEEL-TAN. Dramatic shifts in the dominant microbial species following sodium lactate injection into the TCE plume were observed and were attributed to the onset of reducing conditions, which were induced by the presence of lactate and its fermentation products (propionate and acetate). Although reductive dehalogenation of TCE was observed during the in-situ study, none of the organisms identified have been documented as capable of reductive dechlorination.
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机译：爱达荷州东南部爱达荷州国家工程和环境实验室测试区北部（INEEL-TAN）处的一条断裂玄武岩含水层是长约两英里的三氯乙烯（TCE）污染物羽流的所在地。作为评估在TAN上应用生物修复技术可行性的努力的一部分，确定了潜在负责自然衰减或修复该部位的生物。基于文化和分子生物学方法被用来调查浮游生物和附着的厌氧地下微生物群落。已鉴定出代表22个不同属的许多生物，其中10种通过基于培养的方法，十二种通过使用分子生物学方法直接鉴定。这些结果证实了在这种贫营养但受污染的地下系统中存在着不同的真细菌群落。鉴定出的一种生物体 Pantoea agloglomerans 能够在大约7天的时间内部分降解0.2 mM PCE或0.5 mM TCE。通过调整培养基，进行了许多尝试以实现TCE的完全降解。尽管观察到TCE降解有所增加，但大多数增加与基准性能没有显着差异。我们无法确定为什么仅发生部分TCE降解。分子生物学技术被用来观察在现场大规模应用对被TCE污染的地下水羽状流INEEL-TAN的增强的原位生物修复过程中微生物群落的变化。观察到将乳酸钠注入TCE羽流后，优势微生物物种发生了剧烈变化，这归因于还原条件的发生，还原条件的发生是由于乳酸及其发酵产物（丙酸盐和乙酸盐）的存在引起的。尽管在就地研究中观察到了TCE的还原性脱卤作用，但是没有发现任何鉴定出的生物具有还原性脱氯能力。
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