© H. Singer
As well as being a useful material in all kinds of key technologies, lanthanides are important for bacteria, which use the rare earth metals in their metabolism. It turns out, however, that they are not as irreplaceable as previously thought, as an international and interdisciplinary team led by Professor Lena Daumann from the Department of Chemistry at LMU has demonstrated: Certain bacteria can use the radioactive elements americium and curium instead of the lanthanides – and even prefer them sometimes.
Bacteria that use lanthanides are widespread in the environment. They belong to the so-called methylotrophs, which can use methanol or methane as carbon and energy sources. To do this, they take up lanthanides and incorporate them into an important metabolic enzyme, a lanthanide-dependent methanol dehydrogenase. The elements americium and curium, members of the radioactive actinides, are very similar to the lanthanides when it comes to key chemical properties such as size and charge. “And so we asked ourselves whether the bacteria can use actinides instead of their essential lanthanides,” says Daumann.
