Triphenyl phosphate (TPHP) stress-induced bacterial community differentiation, succession and energy metabolism inhibition under distinct contamination histories.

Triphenyl phosphate (TPHP), a widely used organophosphate flame retardant, is increasingly detected in wastewater systems, landfill leachate-impacted environments, and receiving waters. However, the responses of microbial communities with different contamination histories to TPHP have remained poorly understood. Here, landfill soil and wastewater bacterial communities were subjected to a gradient of TPHP stress under controlled microcosm conditions to assess community, network, and functional responses. The results demonstrated that microbial responses to TPHP were strongly shaped by environmental history. In the landfill soil community, succession followed a consistent directional pattern, as evidenced by the progressive enrichment of Serratia with increasing TPHP concentration. Additionally, the interaction network remains less disrupted compared to the wastewater community, which loses 95.1 % of nodes at a concentration of 70 mg/L. In contrast, the wastewater bacterial community exhibits more pronounced successional shifts and greater simplification of network nodes in response to TPHP. Integrated metagenomic and metabolomic analyses further revealed that TPHP exposure induced broad metabolic reprogramming, particularly affecting amino acid metabolism, purine metabolism, and energy-related pathways. Although the two bacterial community types displayed distinct adaptive strategies, consistent decreases were observed in genes and metabolites associated with the TCA cycle, ATP synthesis, and nucleotide metabolism under TPHP stress. These findings indicated that TPHP not only disrupted the stability of bacterial functions by altering the structure and interaction networks of bacterial communities, but also likely impaired their energy metabolism, thereby weakening the ability of bacterial communities to cope with environmental stress, mediate nutrient transformations, and degrade pollutants.