A magneto-optical microscopic control system for analysis of magnetotaxis and phototaxis sensing in magnetotactic bacteria.

A magneto-optical microscopic control system (MO-MCS) was developed for analyzing the magnetotaxis and phototaxis sensing in magnetotactic bacteria (MTB). The system includes a microscopic image acquisition device, a planar magnetic field generator, a multi-wavelength illumination device, and a host computer control system. The MO-MCS can accurately adjust parameters such as the magnetic field intensity, direction, and the duration and intensity of illumination. Using the system, we analyzed the motion characteristics of Magnetospirillum magneticum AMB-1 wild-type and corresponding mutant strains under various illumination conditions when the magnetic field was reversed. The experiments indicated that the photoreceptor protein Amb2291 and the magnetosensitive protein Amb0994 play complementary roles in the motion behavior of bacteria in response to magnetic field changes under blue light. The MO-MCS provides a valuable tool for investigating the response mechanisms of micro-organisms to environmental physical factors.