The qualitative and quantitative composition of biofilms on microplastic surfaces is widely unknown. A previous study (Zettler et al., 2013; EST) reports the presence of potentially pathogenic bacteria (Vibrio spp.) on floating microplastic particles. Hence microplastics could function as vectors for the dispersal of microorganisms to new habitats. Several Vibrio species are serious human pathogens. Contact with contaminated water and consumption of raw seafood are the main infection factors for Vibrio associated diseases. On research cruises to the North- and Baltic Sea, microplastic particles were collected and subjected to APW (alkaline peptone water) enrichment. Growth on selective CHROMagar™ Vibrio and further identification of isolates by MALDI-TOF (matrix assisted laser desorption/ionization time-of-flight) clearly indicate the presence of potentially pathogenic Vibrio spp. on microplastics. Our results highlight the urgent need for detailed microbiological analyses of floating microplastic particles in the future.

Dangerous hitchhikers? evidence for potentially pathogenic vibrio spp. on microplastic particles

To understand the ecological impacts of the “Plastisphere”, those microbes need to be identified that preferentially colonize and interact with synthetic polymer surfaces, as opposed to general surface colonizers. It was hypothesized that the microbial biofilm composition varies distinctly between different substrates. A long-term incubation experiment was conducted (15month) with nine different synthetic polymer films as substrate as well as glass using a natural seawater flow-through system. To identify colonizing microorganisms, 16S and 18SrRNA gene tag sequencing was performed. The microbial biofilms of these diverse artificial surfaces were visualized via scanning electron microscopy. Biofilm communities attached to synthetic polymers are distinct from glass associated biofilms; apparently a more general marine biofilm core community serves as shared core among all synthetic polymers rather than a specific synthetic polymer community. Nevertheless, characteristic and discriminatory taxa of significantly different biofilm communities were identified, indicating their specificity to a given substrate.

Mature biofilm communities on synthetic polymers in seawater - Specific or general?By: Kirstein, Inga V.; Wichels, Antje; Krohne, Georg; et al.

Marine plastic debris serve as substrates for the colonization of a variety of prokaryote and eukaryote organisms. Of particular interest are the microorganisms that have adapted to thrive on plastic as they may contain genes, enzymes or pathways involved in the adhesion or metabolism of plastics. We implemented DNA metabarcoding with nanopore MinION sequencing to compare the 1-month-old biomes of hydrolyzable (polyethylene terephthalate) and non-hydrolyzable (polyethylene) plastics surfaces vs. those of glass and the surrounding water in a Mediterranean Sea marina. We sequenced longer 16S rRNA, 18S rRNA, and ITS barcode loci for a more comprehensive taxonomic profiling of the bacterial, protist, and fungal communities, respectively. Long read sequencing enabled high-resolution mapping to genera and species. Using previously established methods we performed differential abundance screening and identified 30 bacteria and five eukaryotic species, that were differentially abundant on plastic compared to glass. This approach will allow future studies to characterize the plastisphere communities and to screen for microorganisms with a plastic-metabolism potential.

/pdf/high-resolution-screening-for-marine-prokaryotes-and-2e8sx3ds.pdf

High-Resolution Screening for Marine Prokaryotes and Eukaryotes With Selective Preference for Polyethylene and Polyethylene Terephthalate Surfaces

The microbial colonisers of plastics – the ‘plastisphere’ – can affect all interactions that plastics have with their surrounding environments. While only specifically characterised within the last 10 years, at the beginning of 2021 there were 140 primary research and 65 review articles that investigate at least one aspect of the plastisphere. We gathered information on the locations and methodologies used by each of the primary research articles, highlighting several aspects of plastisphere research that remain understudied: (i) the non-bacterial plastisphere constituents; (ii) the mechanisms used to degrade plastics by marine isolates or communities; (iii) the capacity for plastisphere members to be pathogenic or carry antimicrobial resistance genes; and (iv) meta-OMIC characterisations of the plastisphere. We have also summarised the topics covered by the existing plastisphere review articles, identifying areas that have received less attention to date – most of which are in line with the areas that have fewer primary research articles. Therefore, in addition to providing an overview of some fundamental topics such as biodegradation and community assembly, we discuss the importance of eukaryotes in shaping the plastisphere, potential pathogens carried by plastics and the impact of the plastisphere on plastic transport and biogeochemical cycling. Finally, we summarise the future directions suggested by the reviews that we have evaluated and suggest other key research questions.

/pdf/current-research-on-microbe-plastic-interactions-in-the-23oynxqsn4.pdf

Latva M

Papers

Current Research on Microbe-Plastic Interactions in the Marine Environment