Convergent GenX biodegradation by genomically designed and functionally screened synthetic bacterial consortia

GenX (hexafluoropropylene oxide dimer acid) has been introduced as a replacement for legacy polyfluoroalkyl substances (PFASs) compounds; however, accumulating evidence indicates this C6 ether-PFAS may exhibit comparable toxicity to PFOA while persisting in contaminated water supplies. Biological remediation offers genuine mineralization potential but has been constrained by the exceptional stability of carbon-fluorine bonds. Here, we demonstrate that synthetic bacterial consortia assembled through rational genomic design (GENIA) or microfluidic selection (Community G) achieve rapid GenX biodegradation through metabolic complementarity among functionally specialized taxa. Both consortia removed >80% of GenX within 3 days (GENIA: 94.6%; Community G: 80.6%), with defluorination confirmed by fluoride release (82.6 and 69.6%, respectively). First-order kinetic modeling yielded rate constants of k = 0.87 day^-1 (GENIA) and k = 0.64 day^-1 (Community G), corresponding to half-lives under 1.1 days. Despite pronounced taxonomic divergence, GENIA maintained a stable composition, whereas Community G underwent dramatic restructuring, enriching for specialists of Salmonella, Pseudomonas, and Stenotrophomonas. Comparative genomic analysis revealed functional equivalence, with no significant differences in PFAS-degrading gene content (p = 0.844). Multi-guild community architecture emerged wherein primary degraders (40%-60% abundance) harboring haloacid dehalogenases performed initial C-F bond cleavage, detoxification specialists possessing glutathione S-transferases and fluoride exporters (>90% universal distribution) processed toxic intermediates, and metabolic support taxa enhanced resilience. Molecular docking simulations predicted favorable binding of GenX across phylogenetically diverse dehalogenases (ΔG = -7.0 to -8.1 kcal/mol), suggesting thermodynamic compatibility with enzymatic catalysis. These results are predictive and computational; docking cannot confirm enzymatic activity or substrate turnover. Experimental validation (enzyme kinetics, purified protein assays) is required. Critically, GENIA activity did not disrupt indigenous soil microbiomes. The data support that GENIA does not cause detectable diversity loss, a necessary but not sufficient condition for ecological compatibility. These findings establish that functional gene diversity, distributed across metabolically complementary taxa through either rational design or adaptive selection, enables efficient PFAS bioremediation, converting recalcitrant "forever chemicals" into biodegradable substrates through engineered microbial complexity.