Editorial on the Research Topic
Critical metals, ranging from rare earth elements (REEs) to cobalt, nickel, vanadium, and gallium, are indispensable to modern infrastructure and the global energy transition. Their low natural abundance and geographic concentration create significant supply risks, while conventional extraction methods are energy-intensive and environmentally damaging. At the same time, anthropogenic deposits such as industrial residues, mine tailings, spent catalysts, and waste electrical and electronic equipment contain substantial quantities of these valuable elements. Recovering metals from these secondary resources offers an opportunity to reduce waste, enhance resource circularity, and strengthen strategic metal security.
However, secondary recovery is not without challenges: extraction processes must avoid secondary pollution, minimize chemical inputs, and maintain low energy consumption. Within this context, biotechnology has emerged as a powerful and versatile tool capable of addressing these limitations. Bioleaching, biosorption, biomineralization, enzymatic processes, and protein-based metal binding collectively provide selective, low-impact, and adaptable routes for metal recovery from complex matrices.
The compiled Research Topic illustrates the breadth and maturity of biotechnological innovations applied to the recovery of critical metals, focusing on targeted valorisation of key industrial and urban waste streams. These studies present innovative bio-strategies ranging from bioleaching to biosorption, demonstrating significant advances in sustainable, efficient recovery methods that contribute to the circular economy and the sustainable management of critical raw materials.
Industrial residues such as bauxite residue, iron ore concentrates, coal fly ash, and electronic waste, once considered environmental liabilities, are now recognized as valuable reservoirs of critical metals. The comprehensive review on bauxite residue valorisation highlights microbial bioleaching approaches to extract rare earth elements, gallium, vanadium, and titanium by leveraging optimal microorganisms and metabolic pathway optimization to enhance recovery efficiency, reinforcing circular economy principles (
Advancing molecular and protein-based recovery strategies,
Finally, waste-derived biosorbents employing abundant and low-cost biomasses reveal promising selective recovery of multiple metals from complex electronic waste leachates.
Collectively, these studies represent a continuum of biological innovation, from microbial desulfurization and bioleaching to advanced peptide engineering and biomass-based sorption, illustrating how biotechnology can intervene at every stage of the metal life cycle. They also highlight the dynamism of the field and the growing integration of omics, artificial intelligence, combinatorial biotechnology, and adaptive evolution to design next-generation bioprocesses.
Realising the full potential of biological metal recovery will require interdisciplinary collaboration, methodological innovation, and pilot-scale validation. Hybrid systems that combine biological selectivity with industrial throughput, along with deeper exploration of alkaline residues and underutilized waste streams, will be essential to transforming waste management into resource generation. Continued exchange across microbiology, bioprocess engineering, materials science, and industrial ecology will help overcome remaining challenges and accelerate the deployment of environmentally benign, scalable recovery technologies.
The contributions assembled in
DV: Writing – review and editing, Writing – original draft. EH: Writing – review and editing, Writing – original draft. AP: Writing – original draft, Writing – review and editing. IN: Writing – review and editing.
The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
The authors declare that Generative AI was used in the creation of this manuscript. AI was used only for grammar check and edition of the manuscript.
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