Review: Indigenous peatland bacteria and their role in heavy metal detoxification under extreme biogeochemical constraints

Abstract. Wibowo CNP, Azizah CKG, Risdian DA, Fathurrohman DTA, Tsurayya DA, Rizka DR, Renaldi DR, Saleh DA, Ridwan M, Setyawan AD. 2025. Review: Indigenous peatland bacteria and their role in heavy metal detoxification under extreme biogeochemical constraints. Cell Biol Dev 9: 113-128. Peatlands are among the most efficient natural carbon sinks on Earth, yet their unique physicochemical properties also render them vulnerable to heavy metal accumulation from mining, agriculture, and atmospheric deposition. High organic matter content, persistent acidity, and dynamic redox conditions position peatlands as extreme biogeochemical filters that both immobilize and intermittently remobilize metals, posing complex ecological and restoration challenges. This review synthesizes current knowledge on the role of indigenous peatland bacteria in heavy metal detoxification, emphasizing mechanistic pathways, ecological constraints, and implications for peatland management. We examine how peatland-specific conditions regulate microbial processes such as biosorption, redox transformation, intracellular sequestration, and extracellular polymeric substance production, emphasizing differences between boreal, temperate, and tropical peatlands. Heavy metal detoxification emerges from the integration of multiple mechanisms, such as biosorption, EPS-mediated binding, intracellular sequestration, bioprecipitation, redox transformation, and genetically regulated adaptive networks. The effectiveness of these mechanisms is highly context-dependent and tightly coupled to peatland carbon dynamics, influencing organic matter decomposition and methane fluxes. This review further examines why laboratory-validated microbial processes often fail under field conditions, highlighting the roles of environmental heterogeneity, hydrological fluctuation, scale effects, and ecological mismatch in limiting remediation success. Rather than technology- or strain-centric solutions, evidence supports remediation frameworks that prioritize indigenous microbial consortia, biostimulation, and hydrologically aligned in situ and ex situ pathways. Emerging technologies, including molecular tools, bioelectrochemical systems, and biosensors, are evaluated as enablers that support, but do not replace, ecological processes. By integrating microbial mechanisms with peatland biogeochemistry and restoration science, this review provides a conceptual framework for developing sustainable heavy metal remediation strategies that stabilize contaminants while preserving peatland carbon storage and ecosystem resilience.