Summary: Lanthanides, key components of sustainable energy technologies, can be separated using microorganisms with selective biosorption capabilities that sometimes rival traditional solvent extraction methods. Recent discoveries show that single genetic mutations in Shewanella oneidensis can improve lanthanide biosorption selectivity, while larger genomic modifications in Vibrio natriegens yield greater improvements. To evaluate whether these enhancements are sufficient for industrial implementation, we developed three theoretical models of lanthanide separation by biosorption and desorption. Model 1 suggests that single-locus genetic changes could reduce separation time by 25%, while multi-locus modifications could achieve up to 90% reduction. Model 2 indicates that with multiple binding sites, larger genetic modifications would be necessary for high-purity separation. Model 3 proposes an alternative approach using multiple microbes with modest selectivity improvements: initial microbes enrich the target lanthanide, while subsequent ones remove contaminants.