This study provides 16S amplicon sequencing data on PCLD-polymer-attached microbiomes vs free-living fraction in different WWTPs located in the metropolitan area of Barcelona (Catalonia, Spain). Biodegradation of polycaprolactonediol (PCLD) polymer probes

AbstractThe worldwide growth in the production of plastics together with indiscriminate use and lack of appropriate waste management has led to unsustainable environmental pollution of global concern. The replacement of persistent plastics by degradable polymers is thus of major interest. Hence, determining the key drivers characterizing the degradation of polymers is a rising topic. Here we propose a workflow based on advanced analytical and data treatment methods for the simultaneous identification of the degradation products of polymers exposed to an aquatic environment, as well as, the associated consortia of potential microbial consumers. To test this approach, polycaprolactonediol (PCLD) polymer probes were exposed to different wastewater environments (influent, aerobic, and anaerobic denitrifying reactors) in four different wastewater treatment plants (WWTP). Probes were analyzed by non-target liquid chromatography-high resolution mass spectrometry (LC-HRMS) and the acquired data were processed using advanced chemometric tools (Regions of Interest-Multivariate Curve Resolution-Alternate Least Squares, ROIMCR-ALS). Up to 26 components explaining ca. 69% of the variance were resolved, and 20 of these were further identified. Degradation was dominated by two processes: (a) hydrolysis of the ester groups present in PCLD and (b) formation of cyclic polycaprolactone oligomers. These transformation pathways occurred irrespectively of what were the WWTPs and the treatment stages. Further, the composition of the microbial communities attached to the polymer and free-living in the surrounding water was characterized by 16S rDNA amplicon sequencing analysis. The two communities showed taxonomic differences and, contrastingly with the chemical degradation pathways, they were unique in each WWTP treatment stage.