Bioremediation of sites co-contaminated with organohalides and metal pollutants may have unsatisfactory performance, since metal ions can potentially inhibit organohalide respiration. To understand the detailed impact of metals on organohalide respiration, we tested the effects of four metal ions (i.e., Cu2+, Cd2+, Cr3+ and Pb2+), as well as their mixtures, on reductive dechlorination of perchloroethene (PCE) and polychlorinated biphenyls (PCBs) in three different cultures, including a pure culture of Dehalococcoides mccartyi CG1, a Dehalococcoides-containing microcosm and a Dehalococcoides-Geobacter coculture. Results showed that the inhibitive impact on organohalide respiration depended on both the type and concentration of metal ions. Interestingly, the metal ions might indirectly inhibit organohalide respiration through affecting non-dechlorinating populations in the Dehalococcoides-containing microcosm. Nonetheless, compared to the CG1 pure culture, the Dehalococcoides-containing microcosm had higher tolerance to the individual metal ions. In addition, no synergistic inhibition was observed for reductive dechlorination of PCE and PCBs in cultures amended with metal ion mixtures. These results provide insights into the impact of metal ions on organohalide respiration, which may be helpful for future in situ bioremediation of organohalide-metal co-contaminated sites.

中文翻译：

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金属离子对不同的可吸入有机卤化物的细菌中多氯联苯和全氯乙烯的还原脱氯的抑制作用。

由于金属离子可能会抑制有机卤化物的呼吸，因此对与有机卤化物和金属污染物共污染的场所进行生物修复可能无法令人满意。为了了解金属对有机卤化物呼吸的详细影响，我们测试了四种金属离子（即Cu2 +，Cd2 +，Cr3 +和Pb2 +）及其混合物对全氯乙烯（PCE）和多氯联苯（PCBs）还原脱氯的影响）在三种不同的培养物中进行培养，包括纯麦加德罗球菌CG1培养物，包含脱盐球菌的缩影和脱盐球菌-土壤杆菌共培养物。结果表明，对有机卤化物呼吸的抑制作用取决于金属离子的类型和浓度。有趣的是，金属离子可能会通过影响含Dehaloccocoides的微观世界中的非脱氯种群而间接抑制有机卤化物的呼吸。但是，与CG1纯培养物相比，含Dehaloccocoides的缩影对单个金属离子的耐受性更高。另外，在用金属离子混合物修正的培养物中，未观察到PCE和PCBs的还原性脱氯的协同抑制作用。这些结果提供了有关金属离子对有机卤化物呼吸作用影响的见解，这可能有助于将来对有机卤化物-金属共污染部位进行原位生物修复。在用金属离子混合物修正的培养物中，未观察到PCE和PCBs的还原性脱氯的协同抑制作用。这些结果提供了有关金属离子对有机卤化物呼吸作用影响的见解，这可能有助于将来对有机卤化物-金属共污染部位进行原位生物修复。在用金属离子混合物修正的培养物中，未观察到PCE和PCBs的还原性脱氯的协同抑制作用。这些结果提供了有关金属离子对有机卤化物呼吸作用影响的见解，这可能有助于将来对有机卤化物-金属共污染部位进行原位生物修复。