[Microinterface-scale insights into TBBPA-induced microbial community succession and its coupled migration-metabolism...

Tetrabromobisphenol A (TBBPA), a widely distributed emerging contaminant, exerts stress on microorganisms and undergoes transformation primarily at microinterface regions within soil environments. To systematically elucidate TBBPA migration at the millimeter-scale microinterface and its driving effects on soil microbial communities and metabolic pathways, a millimeter-scale microinterface soil system was constructed and subjected to spatially resolved multi-omics analyses. Results revealed that owing to its pronounced hydrophobicity, TBBPA was strongly enriched within the 0-10 mm surface horizon. By increasing pore abundance and loosening soil aggregates, TBBPA restructured the soil microarchitecture and reshaped microbial ecological niches, leading to a marked decline in α-diversity of bacterial communities within contamination hotspots (decreasing Ace/Chao indices by >42%), with Methylotenera exhibiting the most pronounced shift. Furthermore, TBBPA drove a clear spatial successional gradient: proximal zones were enriched with tolerant and dehalogenating taxa (Micromonospora and Bacillus), whereas distal zones were enriched with ring-cleaving and mineralizing assemblages (Pseudomonas and Methylotenera). Co-occurrence network analysis revealed strong microbial synergism along the vertical axis, characterized by a high proportion of positive correlations (>89%). In contrast, lateral heterogeneity promoted the formation of a compartmentalized network architecture with high modularity (modularity=0.552), which indicated functional differentiation across microenvironments. Metabolomic profiling unveiled a substantial upregulation of key metabolic signatures, including membrane phospholipids, aromatic intermediates, and metal-chelating compounds, in response to TBBPA exposure, alongside a concurrent downregulation of sulfur-related metabolites and signaling molecules. Notably, critical intermediates associated with debromination, ring-opening, and β-oxidation were identified, confirming a multi-enzymatic, stepwise catabolic pathway. This degradation cascade was coupled with the reprogramming of sulfur metabolism, suggesting a metabolic trade-off strategy adopted by soil microbiota during TBBPA detoxification. This study, from a soil remediation perspective, elucidates the microinterface-scale interactions between microorganisms and pollutants, providing a theoretical basis for optimizing microbial consortia and interfacial modifications to enhance the targeted degradation of TBBPA and other hydrophobic organic contaminants.