What comes to your mind when you think about lanthanides aka rare earth elements? We all carry them around in our smartphones, and you might know that industry needs them for numerous high-tech products. Maybe you have also heard that China produces most of them - demands are high and global production is limited.
While it was hypothesized for years that lanthanides would be powerful enzymatic co-factors due to their strong Lewis acidity, lanthanide-dependent enzymes were only discovered a few years ago in methylotrophic bacteria. The biological relevance of lanthanides goes beyond microbiology as positive effects of lanthanides on crop growing and livestock are known for a long time, while the underlying mechanisms are not understood.
In methylotrophic bacteria, lanthanides function as co-factors in methanol dehydrogenase, the key enzyme of methanol oxidation. Taking into account the ecological role of methylotrophs as a sink for diverse C1-compounds, lanthanides are of importance with respect to microbial carbon cycling.
Research dedicated to lanthanide-dependent metabolism is severely limited to a few model organisms that do not adequately cover the taxonomic and expected functional diversity of microbes utilizing lanthanides. We are using recently characterized methylotrophs of the family Beijerinckiaceae to win a more comprehensive understanding about lanthanide-dependent metabolism, including lanthanide uptake, storage and functional roles beyond methylotrophy.