Bacterial degradation of polymer plasticizers on the example of diethyl phthalate (DEP)

The continuing reports of plastic pollution in various ecosystems highlight the threat posed by the ever-increasing consumption of synthetic polymers. Plastics are frequently associated with additives such as phthalic acid esters. Such compounds are used as plasticizers to provide flexibility to plastic products and as common additives in various consumer products, and suspect to cause endocrine disruption in animals.

The bacterial degradation of diethyl phthalate (DEP) as a model compound for plasticizers was studied. In order to isolate bacterial DEP degraders, samples from biofilm on a polyurethane tubing were taken. A bacterial isolate from this biofilm was able to grow in mineral medium with DEP as sole carbon and energy source. The complete degradation of up to 4 mM DEP was confirmed by UPLC analysis. Furthermore, the substrate spectrum of the bacterial culture was assessed by testing different carbon source like trihydroxybenzene, phthalic acid and other aromatics. The bacterial isolate was taxonomically characterized and probably contains at least two bacterial species. In depth 16S rRNA gene sequencing and genome sequencing were conducted to identify the bacterial composition of the DEP degrading culture.