Global advances in magnetotactic bacteria: ecology, evolution and biotechnological applications of BioMagnets with a focus on magnetic hyperthermia

Magnetotactic bacteria (MTB) are an ecologically and physiologically diverse group that synthesizes intracellular nanoparticles, known as magnetosomes (biomagnetic minerals), enabling them to navigate along geomagnetic field lines through microbial magnetoreception. This review provides a comprehensive overview of MTB research from 1979 to 2024, encompassing (i) the cultivation approach, (ii) diverse ecosystems, such as: volcanic lakes, coral reefs, paleosols, acidic peatland, and deep-sea hydrothermal fields, and (iii) ecological and evolutionary studies. To date only two phyla, Pseudomonadota (specifically Alphaproteobacteria, Desulfobacterota, and Gammaproteobacteria) and Nitrospirota have been reported for magnetosomes based biomineralization. Recent advancements in methodologies, including: cultivation-independent approach to survey Magnetosome Gene Cluster (MGCs), 16S rRNA gene characterization, and Cultivation dependent approach for successful isolation of an axenic culture/s of novel MTB strains from diverse ecosystems. The review also highlights the significance of MTB-derived Magnetofossils from paleoenvironmental sediments and emphasizes the importance of Cultivation-independent approach using group-specific primers and alphaproteobacterial sets of primers for direct detection of MTB from the environmental samples. Furthermore, the expanding application of magnetosomes in biotechnology, such as: magnetic hyperthermia for cancer treatment, targeted drug delivery, MTB-based microrobots for isolation of pathogens, and environmental remediation (e.g., pollutant and heavy metal removal from waste water), are discussed.