Chen Jing, Zhao Shuo, Gan Yating, Wu Jing, Dai Jingcheng, Chao Hong-Jun, Yan Dazhong
College of Life Science and Technology, Wuhan Polytechnic University, Wuhan, 430023, China.
University of Chinese Academy of Sciences, Beijing, 100049, China.
Environ Pollut. 2023 Sep 15;333:122063. doi: 10.1016/j.envpol.2023.122063. Epub 2023 Jun 15.
Dichlorodiphenyltrichloroethane (DDT), a persistent organic pollutant, has known effects on natural microbes. However, its effects on soil ammonia-oxidizing microbes, significant contributors to soil ammoxidation, remain unexplored. To address this, we conducted a 30-day microcosm experiment to systematically study the effects of DDT contamination on soil ammonia oxidation and the communities of ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB). Our findings revealed that DDT inhibited soil ammonia oxidation in the early stage (0-6 days), but it gradually recovered after 16 days. The copy numbers of amoA gene of AOA decreased in all DDT-treated groups from 2 to 10 days, while that of AOB decreased from 2 to 6 days but increased from 6 to 10 days. DDT influenced the diversity and community composition of AOA but had no significant effect on AOB. Further, the dominant AOA communities comprised uncultured_ammonia-oxidizing_crenarchaeote and Nitrososphaera sp. JG1: while the abundance of the latter significantly and negatively correlated with NH -N (P ≤ 0.001), DDT (0.001 < P ≤ 0.01), and DDD (0.01 < P ≤ 0.05) and positively correlated with NO-N (P ≤ 0.001), that of the former significantly and positively correlated with DDT (P ≤ 0.001), DDD (P ≤ 0.001), and NH -N (0.01 < P ≤ 0.05) and negatively correlated with NO-N (P ≤ 0.001). Among AOB, the dominant group was the unclassified Nitrosomonadales in Proteobacteria, which showed significant negative correlation with NH -N (0.01 < P ≤ 0.05) and significant positive correlation with NO-N (0.001 < P ≤ 0.01). Notably, among AOB, only Nitrosospira sp. III7 exhibited significant negative correlations with DDE (0.001 < P ≤ 0.01), DDT (0.01 < P ≤ 0.05), and DDD (0.01 < P ≤ 0.05). These results indicate that DDT and its metabolites affect soil AOA and AOB, consequently affecting soil ammonia oxidation.
滴滴涕（DDT）是一种持久性有机污染物，已知其会对天然微生物产生影响。然而，其对土壤氨氧化微生物（土壤氨氧化的重要贡献者）的影响仍未得到探索。为解决这一问题，我们进行了一项为期30天的微观实验，以系统研究滴滴涕污染对土壤氨氧化以及氨氧化古菌（AOA）和氨氧化细菌（AOB）群落的影响。我们的研究结果表明，滴滴涕在早期（0 - 6天）抑制土壤氨氧化，但在16天后逐渐恢复。在所有滴滴涕处理组中，AOA的amoA基因拷贝数在2至10天减少，而AOB的amoA基因拷贝数在2至6天减少，但在6至10天增加。滴滴涕影响AOA的多样性和群落组成，但对AOB没有显著影响。此外，优势AOA群落包括未培养的氨氧化泉古菌和亚硝化球形菌属JG1：虽然后者的丰度与NH₄⁺-N（P≤0.001）、滴滴涕（0.001＜P≤0.01）和滴滴滴（0.01＜P≤0.05）显著负相关，与NO₃⁻-N（P≤0.001）显著正相关，但前者的丰度与滴滴涕（P≤0.001）、滴滴滴（P≤0.001）和NH₄⁺-N（0.01＜P≤0.05）显著正相关，与NO₃⁻-N（P≤0.001）显著负相关。在AOB中，优势菌群是变形菌门中未分类的亚硝化单胞菌目，其与NH₄⁺-N（0.01＜P≤0.05）显著负相关，与NO₃⁻-N（0.001＜P≤0.01）显著正相关。值得注意的是，在AOB中，只有亚硝化螺菌属III7与滴滴伊（0.001＜P≤0.01）、滴滴涕（0.01＜P≤0.05）和滴滴滴（0.01＜P≤0.05）表现出显著负相关。这些结果表明，滴滴涕及其代谢产物影响土壤AOA和AOB，进而影响土壤氨氧化。
