Temperature-dependent biofilm and sublancin production arrest soil arsenic and antibiotic resistance gene mobility

Climate change-induced warming and arsenic soil contamination synergistically threaten agricultural sustainability by restructuring microbial communities and accelerating antimicrobial resistance dissemination. Here, through integrated greenhouse and field trials, we demonstrate that Bacillus subtilis 168-derived biofilm and sublancin, a glycosylated antimicrobial peptide, simultaneously immobilise rhizospheric arsenic and suppress horizontal transfer of antibiotic resistance genes (ARGs). Temperature-dependent biofilm formation (25-35°C) enhanced arsenic sequestration within the extracellular polymeric substance matrix, with SEM-EDX revealing a 74% increase in arsenic weight percentage at 35°C and ToF-SIMS confirming ∼14-fold and ∼9-fold increases in root-associated arsenic on biofilm-colonised surfaces in greenhouse and field trials, respectively. Sublancin production peaked at 30°C (129.72 mg L⁻¹), selectively suppressing all 12 tested pathogenic Gram-positive species by 74-86% while preserving Gram-negative communities. Bio-amendment reduced horizontal gene transfer frequency by 74.7% (p < 0.001) across all temperature regimes. Transcriptomic profiling revealed coordinated upregulation of exopolysaccharide biosynthesis (FDR ∼1.0 × 10⁻²⁷) and sublancin machinery (sunA: +3.5 log₂), alongside downregulation of conventional ARGs (vanA, blaTEM: -2.5 to -4.0 log₂). These findings establish sublancin as a dual-function, climate-adaptive soil bio-amendment simultaneously addressing arsenic bioaccumulation and antibiotic resistance gene dissemination under warming scenarios.