Intracellular Magneto-Spatial Organization of Magnetic Organelles Inside Intact Bacterial Cells

Magnetotactic bacteria naturally produce magnetosomes, i.e., biological membrane bound nano-magnets, at ambient conditions. It is important to understand simultaneously the possible size variations and the magnetic behavior of nano-magnets inside intact bacterial cells for both appli-cational purposes as well as to enhance the basic understanding of biomineralization leading to intracellular nano-magnet synthesis. In this work, we utilize High-resolution Transmission Electron Microscopy and Near-field Scanning Optical Microscopy based measurements on intact non-fixed single cells to rigorously and quantitatively understand the intra-cellular magneto-spatial distribu-tion of nano-magnets synthesized by Magnetospirillum gryphiswaldense. We demonstrate that it is possible to measure the relative magnetic moments along the intracellular magnetosomal chains for intact and non-fixed bacterial cells. Using our in vivo measurements on several single cells, we report that magnetic behavior of intracellular nano-magnets synthesized by magnetotactic bacteria depend on their relative location in the magnetosomal chains. Our work opens promising avenues in the direction of measuring the magnetic behavior of nano-magnets inside living systems by utilizing an operationally straight-forward approach