Di(2-ethylhexyl) phthalate and dibutyl phthalate have a negative competitive effect on the nitrification of black soil
Di(2-ethylhexyl) phthalate and dibutyl phthalate have a negative competitive effect on the nitrification of black soil
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邻苯二甲酸二(2-乙基己基)酯和邻苯二甲酸二丁酯对黑土硝化有负竞争作用
DOI：
10.1016/j.chemosphere.2022.133554
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发表时间：
2022
期刊：
影响因子：
8.8
通讯作者：
Ying Zhang
中科院分区：
文献类型：
--
作者：
Yue Tao;Chong Feng;Jiaming Xu;Lu Shen;Jianhua Qu;Hanxun Ju;Lilong Yan;Weichang Chen;Ying Zhang
邻苯二甲酸二（2-乙基己基）酯（DEHP）和邻苯二甲酸二丁酯（DBP）是农用地膜中使用最广泛的增塑剂，也是黑土中最常见的有机污染物之一。然而，很少有人知道这两种污染物对黑土硝化作用的影响。研究了20 mg/kg DEHP和DBP对硝化微生物群落多样性、氨氧化细菌（AOB）和亚硝酸盐氧化细菌（NOB）相关基因丰度以及硝化关键酶活性的影响。在氨氧化过程中，DEHP和DBP对脲酶具有非竞争性抑制作用，减少了amoA基因的拷贝数，微生物（固氮菌属、链霉菌属和柄杆菌属）会利用无机氮作为氮源进行生理生长。在亚硝酸盐氧化过程中，nxrA基因的拷贝数减少，化能自养硝化细菌（亚硝化单胞菌和硝化杆菌）的相对丰度降低。通径分析结果表明，DEHP和DBP主要通过3种途径直接或间接影响AOB和NOB。这些结果有助于更好地理解DEHP和DBP对黑土中AOB和NOB的生态毒理效应。
Di (2-ethylhexyl) phthalate (DEHP) and dibutyl phthalate (DBP) are the most widely used plasticizers for agricultural mulching films and one of the most common organic pollutants in black soil. However, little is known about the effect of these two contaminants on nitrification in black soil. This study investigated the changes of 20 mg/kg DEHP and DBP on the diversity of nitrification microbial communities, the abundance of ammonia oxidizing bacteria (AOB) and nitrite oxidizing bacteria (NOB) related genes, and the activities of key enzymes involved in nitrification. During ammonia oxidation, DEHP and DBP had uncompetitive inhibition of urease, reducing the copy number ofamoAgene, and microorganisms (Azoarcus,StreptomycesandCaulobacter) would use inorganic nitrogen as a nitrogen source for physiological growth. During nitrite oxidation, the copy number ofnxrAgene also reduced, and the relative abundance of chemoautotrophic nitrifying bacteria (NitrosomonasandNitrobacter) decreased. Moreover, the path analysis results showed that DEHP and DBP mainly directly or indirectly affect AOB and NOB through three ways. These results help better understand the ecotoxicological effects of DEHP and DBP on AOB and NOB in black soil.