Bacterial community drives soil organic carbon transformation in vanadium titanium magnetite tailings through remediation using Pongamia pinnata

Lan Zeng; Zhuo Tian; Xia Kang; Yueyue Xu; Bing Zhao; Qiang Chen; Yunfu Gu; Quanju Xiang; Ke Zhao; Likou Zou; Menggen Ma; Petri Penttinen; Xiumei Yu

doi:10.1016/j.jenvman.2024.121156

Bacterial community drives soil organic carbon transformation in vanadium titanium magnetite tailings through remediation using Pongamia pinnata

J Environ Manage. 2024 May 13:360:121156. doi: 10.1016/j.jenvman.2024.121156. Online ahead of print.

Authors

Lan Zeng¹, Zhuo Tian¹, Xia Kang², Yueyue Xu¹, Bing Zhao¹, Qiang Chen³, Yunfu Gu¹, Quanju Xiang¹, Ke Zhao¹, Likou Zou¹, Menggen Ma¹, Petri Penttinen¹, Xiumei Yu⁴

Affiliations

¹ College of Resources, Sichuan Agricultural University, Chengdu, 611130, China.
² Sichuan Institute of Edible Fungi, Sichuan Academy of Agricultural Sciences, Chengdu, 610066, China.
³ College of Resources, Sichuan Agricultural University, Chengdu, 611130, China; Key Laboratory of Investigation and Monitoring, Protection and Utilization for Cultivated Land Resources, Ministry of Natural Resources, Chengdu, 611130, China.
⁴ College of Resources, Sichuan Agricultural University, Chengdu, 611130, China; Key Laboratory of Investigation and Monitoring, Protection and Utilization for Cultivated Land Resources, Ministry of Natural Resources, Chengdu, 611130, China. Electronic address: xiumeiyu@sicau.edu.cn.

PMID: 38744211
DOI: 10.1016/j.jenvman.2024.121156

Abstract

With continuous mine exploitation, regional ecosystems have been damaged, resulting in a decline in the carbon sink capacity of mining areas. There is a global shortage of effective soil ecological restoration techniques for mining areas, especially for vanadium (V) and titanium (Ti) magnetite tailings, and the impact of phytoremediation techniques on the soil carbon cycle remains unclear. Therefore, this study aimed to explore the effects of long-term Pongamia pinnata remediation on soil organic carbon transformation of V-Ti magnetite tailing to reveal the bacterial community driving mechanism. In this study, it was found that four soil active organic carbon components (ROC, POC, DOC, and MBC) and three carbon transformation related enzymes (S-CL, S-SC, and S-PPO) in vanadium titanium magnetite tailings significantly (P < 0.05) increased with P. pinnata remediation. The abundance of carbon transformation functional genes such as carbon degradation, carbon fixation, and methane oxidation were also significantly (P < 0.05) enriched. The network nodes, links, and modularity of the microbial community, carbon components, and carbon transformation genes were enhanced, indicating stronger connections among the soil microbes, carbon components, and carbon transformation functional genes. Structural equation model (SEM) analysis revealed that the bacterial communities indirectly affected the soil organic carbon fraction and enzyme activity to regulate the soil total organic carbon after P. pinnata remediation. The soil active organic carbon fraction and free light fraction carbon also directly regulated the soil carbon and nitrogen ratio by directly affecting the soil total organic carbon content. These results provide a theoretical reference for the use of phytoremediation to drive soil carbon transformation for carbon sequestration enhancement through the remediation of degraded ecosystems in mining areas.

Keywords: Bacterial community; Mine tailings; Organic carbon transformation; Phytoremediation; Pongamia pinnata; Soil.