College of Resources and Environment, Northeast Agricultural University, 150030, Harbin, China.
College of Geographical Science, Harbin Normal University, 150025, Harbin, China.
Ecotoxicology. 2020 Aug;29(6):801-813. doi: 10.1007/s10646-020-02230-3. Epub 2020 May 22.
Trichloroethylene (TCE) is the most ubiquitous halogenated organic pollutant in the environment, it is one of the 129 priority control pollutants. In order to clarify the influence of TCE on microorganisms and nitrogen transformation in Mollisol is the core purpose of this study. Results showed that 10 mg kg TCE is the concentration limit of ammonification in Mollisol. When the concentration of TCE reached 10 mg kg and the effect lasted for over 7 days, the process of ammonia oxidation to nitric acid in Mollisol will be affected. TCE affected the process of nitrate (NO) transformation into nitrite (NO) by affecting the activity of nitrate reductase, thereby affected the denitrification process in soil. When the concentration of TCE is more than 10 mg kg it reduced the ability of soil microorganisms to obtain nitrogen, thereby affecting soil nitrogen transformation. RDA (Redundancy analysis) showed that the activity of nitrate reductase and the number of nitrifying bacteria and denitrifying bacteria in soil was negatively correlated with the incubation of TCE. In addition, soil nitrate reductase, nitrite reductase, peroxidase activity, ammonifying bacteria, nitrifying bacteria and denitrifying bacteria were negatively correlated with TCE concentration. Beyond that PICRUSt (Phylogenetic Investigation of Communities by Reconstruction of Unobserved States) of functional gene structure depend on KEGG (Kyoto Encyclopedia of Genes and Genomes) showed that 20 mg kg TCE significantly inhibited the metabolism of energy and other substances in Mollisol. Based on the above, it is found that TCE significantly affected nitrification and denitrification in Mollisol, thus the nitrogen transformation in Mollisol was affected by TCE contamination.
三氯乙烯（TCE）是环境中最普遍存在的卤代有机污染物，它是 129 种优先控制污染物之一。为了阐明 TCE 对黑土中微生物和氮转化的影响，是本研究的核心目的。结果表明，10mg/kg TCE 是黑土氨化作用的浓度极限。当 TCE 浓度达到 10mg/kg 且作用持续超过 7 天时，黑土中氨氧化为硝酸的过程将受到影响。TCE 通过影响硝酸还原酶的活性来影响硝酸盐（NO）向亚硝酸盐（NO）的转化过程，从而影响土壤中的反硝化过程。当 TCE 浓度高于 10mg/kg 时，它降低了土壤微生物获取氮的能力，从而影响土壤氮转化。冗余分析（RDA）表明，土壤中硝酸盐还原酶和硝化细菌、反硝化细菌的活性与 TCE 孵育呈负相关。此外，土壤中硝酸盐还原酶、亚硝酸盐还原酶、过氧化物酶活性、氨化细菌、硝化细菌和反硝化细菌与 TCE 浓度呈负相关。除此之外，基于未观察状态重建的群落系统发育学分析（PICRUSt）的功能基因结构依赖于基因和基因组京都（KEGG）表明，20mg/kg TCE 显著抑制了黑土中能量和其他物质的代谢。基于以上结果，发现 TCE 显著影响黑土中的硝化和反硝化作用，从而影响了 TCE 污染对黑土中氮素转化的影响。
