A simple light scattering method to assay magnetism in Magnetospirillum gryphiswaldense

Abstract A simple optical method was developed for assaying cellular magnetism in culture samples of magnetic spirilla. Cells are aligned parallel to the field lines in a magnetic field, resulting in a change in light scattering. The ratio of scattering intensities at different angles of magnetic field relative to the light beam ( C mag ) is used to characterize the average magnetic orientation of the cells. C mag was found to be well correlated with the average number of particles in different magnetic cell populations. Thus, estimations of magnetosome content can be made using magnetically induced differential light scattering. The method provides a fast and sensitive tool for monitoring the magnetite formation in growing cultures of Magnetospirillum gryphiswaldense .