Chemical activation of native cytochrome P450s in soil-derived bacteria by external molecules enables biodegradation of aromatic pollutants

Abstract

The use of genetically engineered microorganisms for pollutant degradation is strictly regulated, limiting their deployment in open environments. To address this challenge, we introduce a non-genetic strategy that activates native soil bacteria to degrade otherwise inert aromatic pollutants. This approach employs small molecules, termed decoy molecules, which mimic native ligands and bind within the active-site cavity of cytochrome P450 enzymes. By partially occupying the substrate-binding pocket, they redirect the enzyme's catalytic activity toward non-native substrates. Using whole-cell biotransformation assays with Priestia megaterium JCM 2506^T (CYP102A1) and Bacillus subtilis JCM 1465^T (CYP102A3), we show that decoy molecules enable hydroxylation of benzene, toluene, xylenes, naphthalene, and halobenzenes. Remarkably, in the presence of decoy molecules, B. subtilis achieved complete degradation of 2-chlorinated dibenzo-p-dioxin within 2 hours at 45 °C. These findings demonstrate an externally controllable, non-genetic means of repurposing native soil bacteria as biocatalysts, offering a promising basis for environmentally compatible bioremediation strategies.