Distribution of magnetotactic bacteria in China and characterization of magnetosomes

摘要

Magnetotactic bacteria (MB), first discovered by Blakemore in 1975, have been constantly found in ponds, rivers, marine and damp grasslands. They all appear to be Gram-negative (G~-), polar or tuft flagella, microaerophilic and morphologically diverse(coccus, bacillus, spirillum and vibrio). In the northern hemisphere, these bacteria orient northward and will swim towards the geomagnetic south pole. The reverse is true of those in the southern hemisphere. At the geomagnetic equator, both southward and northward occur. This behaviour, called magnetotaxis, is possible because they contain magnetosonies which are arranged in chains or at random, and these magnetosonies may be of great value in applications. In the past decade, the research on MB appealed to many scientists, and aerobical MB was isolated by Tadashi et al. in 1991. Until now, however, there have been a few studies on MB in China; and few reports on MB appear in soil in the world. We report here the distribution of MB in the freshwaterand soil in China and characterization of magnetosonies.