Putative degraders of low-density polyethylene-derived compounds are ubiquitous members of plastic-associated bacterial communities in the marine environment.

Maria Pinto,Gerhard J Herndl,Teresa M Langer,Paula Polania Zenner,Jesse Harrison,Meinhard Simon,Marta M Varela

doi:10.1111/1462-2920.15232

Abstract

SummaryIt remains unknown whether and to what extent marine prokaryotic communities are capable of degrading plastic in the ocean. To address this knowledge gap, we combined enrichment experiments employing low‐density polyethylene (LDPE) as the sole carbon source with a comparison of bacterial communities on plastic debris in the Pacific, the North Atlantic and the northern Adriatic Sea. A total of 35 operational taxonomic units (OTUs) were enriched in the LDPE‐laboratory incubations after 1 year, of which 20 were present with relative abundances > 0.5% in at least one plastic sample collected from the environment. From these, OTUs classified as Cognatiyoonia, Psychrobacter, Roseovarius and Roseobacter were found in the communities of plastics collected at all oceanic sites. Additionally, OTUs classified as Roseobacter, Pseudophaeobacter, Phaeobacter, Marinovum and Cognatiyoonia, also enriched in the LDPE‐laboratory incubations, were enriched on LDPE communities compared to the ones associated to glass and polypropylene in in‐situ incubations in the northern Adriatic Sea after 1 month of incubation. Some of these enriched OTUs were also related to known alkane and hydrocarbon degraders. Collectively, these results demonstrate that there are prokaryotes capable of surviving with LDPE as the sole carbon source living on plastics in relatively high abundances in different water masses of the global ocean.

Highlights

Between 4.8 and 12.7 million metric tons of plastic are entering the ocean each year (Jambeck et al, 2015)
Classified as Roseobacter, Pseudophaeobacter, Phaeobacter, Marinovum and Cognatiyoonia, enriched in the lowdensity polyethylene (LDPE)-laboratory incubations, were enriched on LDPE communities compared to the ones associated to glass and polypropylene in in-situ incubations in the northern Adriatic Sea after 1 month of incubation
These results demonstrate that there are prokaryotes capable of surviving with LDPE as the sole carbon source living on plastics in relatively high abundances in different water masses of the global ocean

Summary

Introduction

Between 4.8 and 12.7 million metric tons of plastic are entering the ocean each year (Jambeck et al, 2015). Like all solid surfaces in the ocean, plastics are colonized by microbial communities referred to as the plastisphere (Zettler et al, 2013), which is different in its composition from the microbial communities found in the surrounding environment (Lobelle and Cunliffe, 2011) This has been shown for plastics collected in different locations (AmaralZettler et al, 2015; Oberbeckmann et al, 2015; De Tender et al, 2017; Kettner et al, 2017; C Dussud et al, 2018b; Harrison et al, 2018), and has been observed in both seawater (SW) (Amaral-Zettler et al, 2015) and sediment habitats (Harrison et al, 2014). The bacterium Ideonella sakaiensis produces enzymes capable of efficiently converting poly(ethyleneterephthalate) (PET) into benign monomers (Yoshida et al, 2016)

Results

Discussion

Conclusion