Cross-feeding drives degradation of phthalate ester plasticizers in a bacterial consortium.

Reports of plastic pollution across diverse ecosystems continue to emphasize the environmental risks associated with the increasing consumption of synthetic polymers. Plastics frequently contain additives such as phthalic acid esters, which are extensively employed as plasticizers to enhance flexibility in plastic materials and as constituents of numerous consumer products. These compounds are not chemically bound to polymers, allowing them to leach into the environment and have been implicated as potential endocrine disruptors in animals. In the present study, the bacterial degradation of selected phthalate esters was examined, with diethyl phthalate (DEP) utilized as a model compound. A bacterial consortium capable of degrading DEP was enriched from a biofilm of a polyurethane tubing. The consortium was capable to mineralize DEP as the sole carbon and energy source at concentrations of up to 4 mM, whereas concentrations above 6 mM inhibited its activity due to DEP toxicity. This degradation was only possible by the whole consortium and not by single isolates. The degradation of DEP as well as the timely occurrence of monoethyl phthalate as degradation intermediate was confirmed by UPLC analysis. Metagenomic sequencing identified the consortium as comprising a