Fassbinder J W, Stanjek H, Vali H
Institut für Allgemeine und Angewandte Geophysik, Ludwig-Maximilians-Universität München, FRG.
Nature. 1990 Jan 11;343(6254):161-3. doi: 10.1038/343161a0.
Enrichment of the ferrimagnetic minerals magnetite and maghemite is frequently observed in the top layer of soil horizons. Although both inorganic and organic processes are known to produce magnetite, magnetite in soils has been ascribed to an inorganic origin. We report here the discovery of living magnetic bacteria, similar to those found in salt- and fresh-water sediments, in the A horizon of a well developed soil profile in a typical meadow environment in southern Bavaria. The bacteria were detected in fresh samples using an optical microscope equipped with a rotating magnetic field and a volumetrically calibrated depression slide, permitting accurate counts of the volume density of the organisms. We suggest that magnetic bacteria and their magnetofossils can contribute to the magnetic properties of soils.
在土壤层的顶层经常观察到亚铁磁性矿物磁铁矿和磁赤铁矿的富集。尽管已知无机和有机过程都会产生磁铁矿，但土壤中的磁铁矿一直被认为是无机来源。我们在此报告，在巴伐利亚南部典型草甸环境中一个发育良好的土壤剖面的A层中发现了活的磁性细菌，类似于在咸水和淡水沉积物中发现的那些。使用配备旋转磁场和体积校准凹陷载玻片的光学显微镜在新鲜样品中检测到了这些细菌，从而能够准确计数生物体的体积密度。我们认为磁性细菌及其磁化石可能对土壤的磁性特性有贡献。
