Environmental Science and Engineering Seminar

Since the discovery of the first rare earth element (REE)-dependent enzyme, XoxF, just over a decade ago, REEs—particularly the lanthanides—have emerged as a new class of biologically relevant metals. In this work, we investigate the diverse strategies employed by environmental microbes, including Methylobacterium and Bradyrhizobium to mobilize and utilize lanthanides. We describe the characterization of lanthanide-binding chelators with unique chemical moieties that facilitate REE solubilization and uptake under environmentally relevant conditions, and examine the crosstalk between REEs and other metal ions within microbial metabolic networks.

We further elucidate the molecular machinery required for lanthanide trafficking and utilization, including the identification of novel peptides and transport pathways that enable discrimination between light and heavy lanthanides. In addition, we examine the role of lanthanides in shaping microbe–microbe and microbe–plant interactions, highlighting their broader ecological significance.

As global demand for lanthanides—critical components in clean energy technologies—continues to rise, there is increasing interest in sustainable recovery strategies. We demonstrate that Methylobacterium extorquens represents a promising green chassis for REE biorecovery, with the capacity to extract and concentrate lanthanides from diverse and complex waste streams.