Isolation and Characterization of Magnetotactic Bacteria

A total of 53 sediment and soil samples were collected from a wide range of natural environments across China and Australia (Fig. 2a), including 13 sediment samples that have been described previously [41 (link), 88 ] (for details, see Supplementary Table 1). Each sample was examined for the presence of living MTB by light microscopy using the hanging-drop method [89 (link)]. MTB cells from sediments and peatland soils were enriched magnetically using a “MTB trap” and enriched MTB cells were then subjected to metagenomic analyses, the detailed procedures for which are described elsewhere [45 (link), 90 (link)]. The morphologies of enriched cells were examined using a JEM-2100 HR transmission electron microscope (JEOL, Japan) at 200 kV.