Yang_2026_J.Environ.Manage_404_129555

This study investigated the enzymatic degradation and proteomic mechanisms of four complex organophosphate flame retardants (OPFRs) by screened Bacillus pacificus strains L2. Under optimal conditions (30 degreesC, 1 mg L(-1) mixed pollutants), the enzymes exhibited remarkable degradation performance: 90% degradation rate for TCP within 24h, 54% for TPhP, and approximately 20% for two chlorinated OPFRs. Cu(2+), Ca(2+) and Fe(3+) inhibited OPFRs degradation, whereas Zn(2+) and Mg(2+) significantly enhanced TCEP and TCPP degradation to 33% and 53% respectively. The results demonstrated that OPFRs-degrading enzymes were primarily intracellularly distributed, with degradation efficiency influenced by initial pollutant concentration, reaction temperature, and metal ions. Proteomic analysis revealed key enzymes involved in OPFRs biodegradation, including inorganic pyrophosphatase, phosphoesterase, carboxylesterase, laccase, and oxidoreductase, which facilitated pollutant dechlorination and decomposition through hydrolysis and hydroxylation. Notably, superoxide dismutase (SOD), catalase (CAT), ribonuclease (RNase) and ribosomal proteins were upregulated during OPFRs biodegradation, indicating strain L2's adaptive responses through antioxidant defense and genetic stability maintenance under OPFRs stress.