Fundamental aspects of practical applications of magnetotactic bacteria (abstract)

Recently, we reported the possibility to apply magnetotactic bacteria for domain studies.1 The high field sensitivity (≊30 A/m) yields effective orientations in the stray field of domains and thus their visualization. Here, we discuss fundamental aspects of broader applications including the collection of bacteria. For it, by means of numerical analysis, a magnetic trap was developed in order to guide bacteria in concentration vessels. With respect to the low active velocity (100 μm/s), also possibilities of passive guidance by means of gradient fields were studied, which, however, yielded minimum intensities of more than 1 kA/m. Roughly, this is consistent with results of susceptibility measurements showing magnetic moments of only 10−14 Am2 for bacteria of 1 μm diameter. Still, passive guidance could enable rapid concentration and translocation procedures, e.g., using the bacterium as a drug carrier. Future applications could include the use of genetically manipulated bacteria in biotechnology. As a pil...