the capacity of plants and microorganisms to react to the presence of a particular metal by growing toward (positive metallotropism) or away (negative metallotropism) from it.
The positive metallotropism of the mucoraceous fungus Phycomyces nitens to iron was discovered in 1892 by the Finnish botanist P. Elving. Negative metallotropism to copper and positive metallotropism to iron and aluminum were discovered in the same fungus by the Russian botanist A. G. Genkel’ in 1905. Metals which, under the influence of radioactivity of the environment (air, soil), emit insignificant secondary radiation (for example, aluminum) produce positive metallotropism; metals that are intensely radioactive, such as copper, produce negative metallotropism. The distant negative effect of metals on bacteria and mustard sprouts was established by the Russian microbiologists G. A. Nadson and E. A. Shtern in 1937.