Research Trends in Microbial Remediation of Heavy Metal-Contaminated Soils: A Bibliometric Analysis

Heavy metal contamination in soils threatens ecosystem stability, agricultural productivity, and human health due to its persistence, toxicity, and ecological risks. Microbial remediation has emerged as a sustainable and cost-effective strategy, but the knowledge structure and research trends in this field remain insufficiently summarized. This study conducted a bibliometric analysis of publications on microbial remediation of heavy metal-contaminated soils retrieved from the Web of Science Core Collection from 2000 to 2025. VOSviewer (version 1.6.20), CiteSpace (version 7.0.R0), and the bibliometrix package (version 4.5.0) were used to analyze publication trends, major contributors, influential journals, and keyword evolution. The results showed that the number of publications increased continuously, with rapid growth after 2020. China, India, and the United States were the leading contributors, while Poland, Spain, and the United States played important bridging roles in international collaboration. Ravi Naidu was the most cited author, and Journal of Hazardous Materials was the most productive journal. Keyword analysis revealed a shift from pollutant degradation and microbial screening toward plant-microbe synergistic remediation, co-contaminated soil treatment, microbial community responses, and ecological risk assessment. Future research should emphasize multi-omics-based mechanisms, long-term in situ applications, and integrated evaluation frameworks.