Abstract: Disclosed herein are magnetotactic algae, such as algae cells that include magnetic nanoparticles. In some examples the magnetotactic algae express a nucleic acid molecule encoding a bacterial MagA ferrous transporter, a nucleic acid molecule encoding a bacterial Mms6 magnetite binding protein, or both. Also disclosed herein are methods for producing magnetotactic algae and methods of producing biofuel or magnetic nanoparticles utilizing magnetotactic algae. Further disclosed herein are methods of enriching a population of magnetotactic algae cells (for example, increasing the number of magnetotactic algae cells in a population of algae cells). In further embodiments, disclosed herein are methods of selecting a transformed algae cell.

Abstract: Permanent magnet assemblies include a central cylindrical magnet having a bore. The cylindrical magnet is magnetized along a selected radial direction and is enclosed within a ferromagnetic shim. A uniform magnetic field, field gradient, or other field distribution can be produced in the bore based on the bore cross-sectional shape.