Metabolomics and structural modeling reveal the mechanism of broad-spectrum phthalate degradation by an enriched microbial consortium.

Abstract

Di-n-butyl phthalate (DBP) pollution poses significant ecological risks, necessitating effective green remediation strategies. This study constructed a robust microbial consortium (DBP-Micro-con) and systematically elucidated its degradation mechanism using an integrated multi-omics approach. Community analysis provided that enrichment culture shifted the dominant phylum from Pseudomonadota, Acidobacteriota and Actinomycetota to Bacillota. The consortium achieved 99.07% DBP removal within 120 h, significantly outperforming isolated single strains. It exhibited remarkable environmental robustness across pH 5-10 and temperatures 20-38 °C, alongside broad-spectrum degradation capabilities against di-n-octyl phthalate (DOP) and various strobilurin fungicides. Non-targeted metabolomics identified mono-butyl phthalate (MBP) as intermediate and show metabolic profile changes, particularly in nucleotide and glycerolipid pathways. Furthermore, homology modeling and molecular docking of the key carboxylesterase CES1281, despite moderate sequence similarity, provided structural insights into the catalytic mechanism. This identified a conserved catalytic triad (Ser113-Asp166-His197) and critical hydrophobic interactions stabilizing substrate binding. Collectively, these findings advance the theoretical understanding of PAE biodegradation and offer a promising microbial resource and mechanistic framework for remediation of composite pollution.