Microbial bioleaching of rare earth elements from phosphate minerals: a biotechnology-driven systematic review of mechanisms, bioprocess determinants, and opportunities for sustainable recovery

Microbial bioleaching is a promising biotechnological platform for REE recovery from phosphate minerals, driven by metabolically diverse acidogenic, chelating, enzymatic, and redox mechanisms. However, advancements remain constrained by heterogeneous methodologies, limited integration of mechanistic studies, and minimal use of engineered strains or controlled bioreactor systems. Future progress requires standardized experimental frameworks, improved mechanistic understanding of organism-specific roles, and rational design of optimized microbial systems. This review offers a biotechnology-centered foundation to guide next-generation research on sustainable REE mobilization from phosphate resources.