This news release is available in German.
Rare earths are among the most precious raw materials of all. These metals are used in mobile telephones, display screens and computers. And they are apparently indispensable for some organisms as well. A team of researchers, including scientists from the Max Planck Institute for Medical Research in Heidelberg, has discovered a bacterium which needs rare earths to grow - in a hot spring. Methylacidiphilum fumariolicum requires lanthanum, cerium, praseodymium or neodymium as co-factor for the enzyme methanol dehydrogenase, with which the microbes produce their energy. The use of rare earths is possibly more widespread among bacteria than previously thought.
In reality, the 17 metals that belong to the group of rare earths are not rare at all. The Earth's crust contains larger quantities of rare earths than of gold or platinum, for example. The problem is that the elements have a relatively even distribution, so that mining is economical in only a few places.
In living organisms, the rare earths really are rare, on the other hand. As they dissolve hardly at all in water, most organisms cannot use them for their metabolism. This makes their discovery in a mudpot of volcanic origin in the Solfatara crater in Italy all the more surprising. Microbiologists from the Radboud University in Nijmegen, the Netherlands, have found a microbe which cannot live without some of the rare earths.
Methylacidiphilum fumariolicum belongs to a group of bacteria which have chosen an extremely inhospitable habitat: They thrive best at a pH value of between 2 and 5 and temperatures of between 50 and 60 degrees - conditions which are lethal for other organisms. Methylacidiphilum even tolerates pH values below 1, which
|Contact: Dr. Thomas Barends|