Magnetotactic bacteria were magnetically
collected the same day in the laboratory from eight bottles
after homogenisation of the samples by placing the south
pole of 0.4 T permanent magnets against the outer surface
of the bottles [4]. After 30 min, bacteria in the brownblackish
spots underneath the magnets were collected with
a pipette, counted and inspected using the hanging-drop
approach [4], and magnetically purified by the race-track
method using 0.4 T permanent magnets, as previously
described [24]. Purified MTB were used for microscope
observations and DGGE analyses