Evidence for mechanosensitive transmembrane ion channels of small conductance in magnetotactic bacteria

To determine whether or not mechanosensitive (MS) ion channels are present in the magnetotactic bacterium Magnetospirillum magnetotacticum, techniques for spheroplast preparation in Escherichia coli were adapted for this bact erium. This resulted in the formation of 2-3-mu m spheroplasts, which were used for patch clamp analysis. Ion channel activity in M. magnetotacticum w as compared with that of the MS of small conductance (MscS) in E. coli. Thi s comparison reveals the presence of MscS-like channels in M. magnetotactic um and, as this bacterium produces intracellular magnetite (Fe3O4) particle s similar to those found in the human brain, provides a model for investiga tion of the effects of magnetic fields on MS ion channels in magnetite-bear ing cells.