Edaphic factors mediate the response of nitrogen cycling and related enzymatic activities and functional genes to heavy metals: A review

作者：Tracy Opande, Mengru Kong, Di Feng, YuHong Wen, Nathan Okoth, Ali Mohd Yatoo, Fatma Mohamed Ameen Khalil, Ahmed S. Elrys, Lei Meng, Jinbo Zhang · 发表于：Ecotoxicology and Environmental Safety · 年份：2025 · DOI：10.1016/j.ecoenv.2025.117766 · 被引用次数：32 · 研究领域：Chromium effects and bioremediation、Adsorption and biosorption for pollutant removal、Heavy metals in environment

Soil nitrogen (N) transformations control N availability and plant production and pose environmental concerns when N is lost, raising issues such as soil acidification, water contamination, and climate change. Former studies suggested that soil N cycling is chiefly regulated by microbial activity; however, emerging evidence indicates that this regulation is disrupted by heavy metal (HM) contamination, which alters microbial communities and enzyme functions critical to N transformations. Environmental factors like soil organic carbon, soil texture, water content, temperature, soil pH, N fertilization, and redox status play significant roles in modulating the response of soil N cycling to HM contamination. This review examines how different HMs affect soil N processes, including N fixation, mineralization, nitrification, denitrification, dissimilatory nitrate reduction to ammonium (DNRA), and immobilization, as well as microbial activities and functional genes related to soil N transformations. The review additionally outlines the impact of HMs on environmental degradation, including the risk of soil N losses (e.g., leaching, runoff, and gaseous emissions) and depletion of soil fertility, thus threatening the sustainability of the ecosystem. The effect of edaphic factors and fertilization on soil N cycling response to HM contamination was also examined. The effect of phytoremediation, a sustainable approach to remediate HM polluted soils, on N cycling was also reviewed. Thus, t...