Harnessing Microbial Bioremediation and Wastewater Valorization for Production of (Methyl)muconates via Engineered Metabolic Pathways in Aromatic Pollutant Mixtures.

Industrial effluents, particularly (semi)coking wastewaters, pose significant environmental challenges due to their complex aromatic pollutants. This study introduces an innovative approach by engineering Pseudomonas putida BGR4, a robust biodegradative chassis, for the treatment and transformation of simulated aromatic pollutant mixtures of semicoking wastewater into high-value compounds such as (methyl)muconates. We integrated degradation pathways for benzene, toluene, (methyl)phenols, and naphthalene (∼30 kb) into the bacterial chromosome, and through adaptive laboratory evolution (ALE), developed strain BGCW, which can completely mineralize 68.57% by weight of the organic compounds in semicoking wastewater. Additionally, by disrupting the muconate utilization and catechol meta-cleavage pathways and overexpressing catechol ortho-cleavage genes, strain BGMA achieved a 48.50 ± 5.84% (mol/mol) production yield of (methyl)muconates from 20% (w/v) simulated aromatic pollutant mixtures. This study provides an innovative approach to efficiently treat aromatic pollutant mixtures of semicoking wastewater while converting pollutants into valuable chemicals, offering significant benefits for both environmental remediation and resource recovery.