Hyphomicrobium spp. thriving at lanthanide-enriched sites can complement biomining alternatives

Abstract Current biomining alternatives focus on exploiting metal-binding proteins with an exceptional affinity for lanthanides (Ln3+). Herein, we developed an in-silico competition model for ionic binding indicating the α-proteobacterium, Hyphomicrobium methylovorum, possesses a protein that potentially binds Ln3+ more efficiently than previous homologous protein studies demonstrate. Data regarding microbial receptors mediating acquisition of Ln3+ for intracellular transport, however, remain scarce. We therefore determined the in-silico binding capacity of an H. methylovorum outer membrane receptor for a chelating siderophore of Ln3+. These in-silico results directed us to examine the microbiome of a former coal mine, now metal-polluted lake in Czechia, where we identified twelve distinct Hyphomicrobium spp. indigenous to the bottom ferruginous waters. As consortia members of Fe(II)-/Mn(II)-oxidizers within waters often enriched in Ln3+, our findings suggest that select Hyphomicrobium possess a sufficient molecular armament for scavenging Ln3+. Hyphomicrobium scavenging capacity of Ln3+ can complement and diversify current alternatives implementing biotechnological mining methods.