Now, James Byrne and his colleagues from the University of Tübingen in Germany have discovered that an ordinary magnetic mineral, tiny magnetite grains, can act as both an electron acceptor and an electron donor, thus working as efficiently as a battery. . He let a community of Geobacteria and Rhodopseudomonas strains grow on the magnet, and then found that Geobacteria can "drop" electrons onto the crystal, and Rhodopseudomonas get electrons from the crystal .

      Byrne said that in the natural environment, these two reactions may occur according to the day and night cycle or the period of rising and falling tides, and each strain is active at different time points in this cycle. He also said that for the bacterial community, magnetite crystals act like natural rechargeable batteries: they are charged by Geobacteria and consume electricity by Rhodopseudomonas.

      Lars Peter Nielsen from Aarhus University in Denmark said the discovery was exciting and provided complete information about the multiple roles that magnets have as a mineral in geomicrobiology. According to the different needs of strains, magnets can be used as a conductor or a "storage box" and source of electrons.

      This is indeed shocking. Studies have found that strains grow on tiny particles of natural magnets. These strains of bacteria are a mixed community that can "swallow" and "breath" electrons from metals. In recent years, power generation bacteria have become a hot topic. Scientists have discovered that some strains of bacteria found on the ocean floor and riverbeds around the world can obtain electrons from tiny metal particles. By "donating" electrons to the strain, iron particles become an effective source of energy for cells. Other types of bacteria effectively breathe electrons by "dropping" excess electrons onto metal particles.