Unveiling phthalate esters biodegradation from microbial community to Pseudarthrobacter scleromae HL-1: Kinetics, genomic insights, pathways, toxicity assessment and environmental remediation.

Phthalate esters (PAEs) are ubiquitous synthetic plasticizer pollutants posing severe ecological and human health risks. This study compared microbial community structures and dibutyl phthalate (DBP) degradation kinetics of two consortia: 7-day enriched MC1 (50 mg/L DBP) and 6-cycle acclimated MC7 (50-1000 mg/L DBP), demonstrating directional DBP stress selection generated a low-diversity, highly specialized degradative community with a 25.4 mg/L/h maximum degradation rate (Vmax), 1.68-fold higher than MC1. Four dominant DBP-degrading strains were isolated from MC7; Pseudarthrobacter scleromae HL-1 showed the highest efficiency with 17.1 mg/L/h Vmax and complete 500 mg/L DBP removal within 72 h, broad substrate spectrum, and strong adaptability after optimization. Whole-genome sequencing and GC-MS/MS elucidated a dual-parallel DBP mineralization pathway, first reported in Pseudarthrobacter, integrating ester hydrolysis and side-chain β-oxidation. ECOSAR and Chlorella vulgaris bioassays confirmed progressive toxicity attenuation, with > 99% relative toxicity reduction after 72 h and no toxic intermediate accumulation. Natural lake water trials with trace background PAEs showed HL-1 successfully colonized aquatic environments, reshaped indigenous communities into synergistic degradative consortia, and achieved 99.2% DBP removal in 84 h. This work provides comprehensive insights into PAE biodegradation mechanisms from community to single strain and highlights HL-1 as a promising candidate for remediating PAE-polluted aquatic ecosystems.