Magnetic Field Modulation of Microbial Functional Specialization for Optimizing Environmental Bioprocesses: A Review
Microbial communities are the core functional units in environmental biotechnology. Magnetic field technology, as a non-invasive physical enhancement method, has shown application potential in wastewater treatment and waste resource recovery. Traditional ecological theory posits a positive correlation between species diversity and system function/stability. However, magnetic field enhancement often coincides with improved system performance and decreased microbial diversity, indicating a decoupling. This review systematically explains this phenomenon as the result of magnetic field-driven functional specialization of microbial communities. Magnetic fields act on paramagnetic targets in energy metabolism, including iron-sulfur clusters and cytochromes, alter cell surface physicochemical properties, impose oxidative stress, and select strains with high metabolic flexibility, thereby achieving targeted enrichment of key functional groups such as ammonia-oxidizing bacteria and electroactive bacteria within Proteobacteria. Although such functionally specialized communities have reduced species richness, they exhibit higher energy metabolism efficiency, enhanced electron transfer capacity, optimized interspecies cooperation networks, and strengthened system robustness. These advantages collectively support efficient and stable macroscopic bioprocess performance. This study also discusses potential limitations regarding ecosystem resilience and scenario dependence, and envisions future directions such as quantitative modeling and synergy with magnetic materials to advance magnetic field technology from empirical application to rational design.