Genomic and proteomic profiles of biofilms on microplastics are decoupled from artificial surface properties

Abstract

Microplastics in marine ecosystems are colonized by diverse prokaryotic and eukaryotic communities. How these communities and their functional profiles are shaped by the artificial surfaces remains broadly unknown. In order to close this knowledge gap, we set up an in situ experiment with pellets of the polyolefin polymer polyethylene (PE), the aromatic hydrocarbon polymer polystyrene (PS), and wooden beads along a coastal to estuarine gradient in the Baltic Sea, Germany. We used an integrated metagenomics/ metaproteomics approach to evaluate the genomic potential as well as protein expression levels of aquatic plastic biofilms. Our results suggest that material properties had a minor influence on the plastic-associated assemblages, as genomic and proteomic profiles of communities associated with the structurally different polymers PE and PS were highly similar, hence polymer-unspecific. Instead, it seemed that these communities were shaped by biogeographic factors. Wood, on the other hand, induced the formation of substrate-specific biofilms and served as nutrient source itself. Our study indicates that, while PE and PS microplastics may be relevant in the photic zone as opportunistic colonization grounds for phototrophic microorganisms, they appear not to be subject to biodegradation or serve as vectors for pathogenic microorganisms in marine habitats.

Microalgae colonization of different microplastic polymers in experimental mesocosms across an environmental gradient

“…Previous research from marine environments showed similar results to those observed in this study, reporting that geography is likely to be a stronger predictor of plastisphere community composition at the scale of ocean basins (Harrison et al, 2018 ; Oberbeckmann et al, 2021 ). However, this is still under debate with several studies suggesting substrate‐driven selection, with differences reported not only when comparing inert control material to plastic substrates (e.g., Miao et al, 2019 ; Ogonowski et al, 2018 ) but also when colonization on different plastic polymers was evaluated (e.g., Li et al, 2019 ; Pinto et al, 2019 ).…”

Into the Plastisphere, Where Only the Generalists Thrive: Early Insights in Plastisphere Microbial Community Succession

“…Omitting the need for PCR and its associated biases, future investigations into the metagenomes or metatranscriptomes of these microbes and communities may reveal additional taxonomic details. Using genomics and proteomic profiling, Oberbeckmann et al (2021) reported that the properties of polyethylene and polystyrene pellets had little influence on their associated microbial communities, they were similar on both substrate types. Future community-based assessments, including from metagenomics and proteomics data, as used by Oberbeckmann et al (2021), may further help to identify appropriate sites for the later enrichment and isolation of potential plastic biodegrading organisms.…”

“…Using genomics and proteomic profiling, Oberbeckmann et al (2021) reported that the properties of polyethylene and polystyrene pellets had little influence on their associated microbial communities, they were similar on both substrate types. Future community-based assessments, including from metagenomics and proteomics data, as used by Oberbeckmann et al (2021), may further help to identify appropriate sites for the later enrichment and isolation of potential plastic biodegrading organisms. In particular, confirmation of the presence of complete plastic biodegradation pathways, along with their corresponding regulatory mechanisms could help to identify environments and sites for the mining of novel plastic degrading genes and taxa.…”

Rapid Degradation of Cellulose Diacetate by Marine Microbes

“…As positive controls, we tracked Kraft paper film and cotton fabric, both cellulosic in nature. As negative controls, − we tracked a polyethylene (LDPE) film and polyethylene terephthalate (PETE) fabric. Time-lapse photography and mass loss measurements documented the disintegration of these materials.…”