Microbial hitch-hikers of marine plastics: the survival, persistence & ecology of microbial communities in the Plastisphere

Lead Research Organisation: Bangor University
Department Name: Sch of Natural Sciences

Abstract

The most abundant form of litter in the marine environment is plastic, and the negative and detrimental consequences of plastic debris on fish, reptiles, birds and mammals are well documented. The hard surface of waterborne plastic provides an ideal environment for the formation of biofilm for opportunistic microbial colonisers; however, our knowledge of how microorganisms interact with microplastics and alter the dispersal behaviour of marine plastics in the environment is a significant research gap. Biofilm at the interface between the plastic surface and the environment has been termed the 'Plastisphere', and although plastics are extremely resistant to decay, variability in composition determines their specific buoyancy and surface rugosity, which will dictate the extent of microbial colonisation and their ability for long distance dispersal. Furthermore, because plastic debris can persist in the marine environment longer than natural substrates, e.g. feathers and wood, it offers an opportunity for the wider dissemination of pathogenic and harmful microorganisms.

Microplastics from clothes, cosmetics and sanitary products are now common constituents of sewage systems and they frequently bypass the screening mechanisms designed to remove larger waste items from being exported to coastal waters. Microplastics entering aquatic systems from waste water treatment plants (WWTPs) come in close contact with human faeces, hence providing significant opportunity for colonisation by faecal indicator organisms (FIOs) and a range of human bacterial pathogens. Importantly however, there have never been any studies investigating the ability of enteric viruses binding to microplastics (or binding to the biofilm on the plastic surface), and this now needs critical evaluation in order to understand this potentially novel mechanism for the environmental dispersal of enteric viruses. Furthermore, there is growing evidence that the plastisphere can promote gene exchange, and so determining the potential of plastisphere biofilms for providing the surface for anti-microbial resistance (AMR) gene transfer is of the utmost importance. There is currently a lack of fundamental understanding about the mechanisms by which microorganisms, particularly pathogenic bacteria and viruses, can "hitchhike" on microplastic particles and be transported to beaches, bathing waters, shellfish harvesting waters and high benthic diversity zones. Consequently, it is not yet possible to determine the risk from these potential pathways, or establish environmental monitoring guidelines for informing future policy or environmental regulation. Therefore, the novelty of this project is to quantify the processes that are occurring within the plastisphere, and understand the potential for the vectoring of pathogenic viruses and bacteria.

Previous research on chemical co-pollutants present on plastics often fails to consider the likely impacts of plastisphere communities. Microplastics in the environment are potential vectors for these chemicals, which often desorb when ingested by marine species, and can accumulate in the food chain. Microbes in the plastisphere may either mitigate this problem through biodegradation, or enhance it by increased biofilm binding; however, most laboratory-based studies are carried out with pristine non-colonised plastics, and ignore the pivotal role the plastisphere plays on defining the risk of microplastics in the environment. By understanding the multi-pollutant and multi-scale effects of microplastics, the "Plastic Vectors Project" will help to establish a more accurate risk assessment of microplastics by taking into consideration the effects of harmful plastic-associated microbes together with chemical co-pollutants.
Therefore, the "Plastic Vectors Project" aims to quantify the significance and function of microbes in the 'plastisphere', and will deliver feasible solutions for reducing these multi-pollutant risks.

Planned Impact

This project addresses an issue of global relevance, and therefore the impact will be far-reaching. A range of key stakeholders have been actively engaged in the formulation and writing of this proposal to ensure that it directly meets their needs, complements existing research and is fit for purpose. Specifically, this proposal will be of benefit to policy makers and regulators, both national and international. The main UK beneficiaries will be Defra, Scottish Environmental Protection Agency, Environment Agency (and devolved equivalents), the NHS, and NGOs, e.g. Surfers Against Sewage, as well as UK academia. In addition, our research output will be of use to those water companies gearing up to significantly invest in measures to update wastewater infrastructure; our project offers a time-limited opportunity to prepare for the developing legislation aimed at mitigating the release of microplastics from WWTPs. The project will also benefit healthcare providers (e.g. NHS) by generating additional knowledge of the potential health impact of microplastics and the unknown dimension of how microplastics may in fact support other human health hazards and exposure pathways. Internationally, the work will directly inform the European Environment Agency, EU-DG MARE and EU-DG SANCO; additionally, data from this project will be significant for European legislation on the use of microplastics as ingredients in cosmetics and sanitary products.

The project team are well-placed to ensure that research findings are disseminated with highest impact given existing links to Defra, SEPA & other bodies. UK regulators will gain access to more complete and integrated understanding of how multiple hazards can interact in aquatic systems. Our results will provide more certainty with regard to the multi-pollutant and multi-scale effects of microplastics, and will deliver a more accurate risk assessment of microplastics by integrating the effects of harmful plastic-associated microbes together with chemical co-pollutants. Importantly, the "Plastic Vectors Project" will benefit from an advisory board of invited experts (see letters of support) who will enable critical evaluation of the direction of the project, and thus endorse our approach as 'fit-for-purpose' for a wide range of relevant stakeholders

We propose a multifaceted way of disseminating our project findings and realising impact. To engage with our stakeholders we will capitalise on our strengths of disseminating results to public, scientific, regulatory and policy audiences by using radio and TV interviews, public meetings (e.g. Café Scientifique), stakeholder and KE workshops, bespoke websites, social media, scientific and non-scientific publications. We aim to stimulate interest in the multi-pollutant impacts of microplastics covered in our project by targeting young people and children at science fairs and festivals (in Scotland, Wales and England), and inspiring change in the way we interact with plastics in our everyday lives.

Publications

10 25 50
 
Description In Frames of WP1 the Bangor team was developing a novel Particle Tracking Method (PTM) to predict and visualise the end-life of microplastic once it has entered the marine environment. This method will, for the first time, identify plastic sources, their pathways and sinks - taking into account different plastic types, behaviours, transformations and interactions. Comprehensive methods to simulate plastic dispersal are so far undeveloped across a range of scales and plastic compositions. We are currently leading the way in this field by developing new models that: (i) accurately simulate 3D integrated catchment-to-coast hydrodynamics suitable for plastic dispersal modelling - applied to two contrasting catchments and estuaries; (ii) incorporate a range of microplastics of different compositions and densities; (iii) simulate changes in plastic composition such as through biofilm development that include microbial communities, microplastic breakdown, aggregation, and changes in chemical composition; and (iv) boundary effects such as interactions with seabed sediment or surface wind drag. This will be the first time that these important parameters are incorporated in a single modelling framework across the freshwater-marine continuum.

In WP1, using microcosm studies, Bangor team has analysed the microbial colonisation of selected microplastics and plasticisers. Conwy river water was sampled at the effluent of wastewater treatment plant (Llanwrst), and 450 m upstream and downstream from the effluent. These water samples were placed in the flasks and subjected to six main treatments with five unique plastics added as substrates (in triplicates). Flasks were incubated under controlled conditions and were sampled at four different timepoints yielding 360 samples in total, in which we established microbial communities' compositions using barcoded Illumina amplicon sequencing. In these studies, Bangor team has produced important baseline data on microbial communities in Conwy River and adjusted methodologies for sampling, sample processing and analysis that are essential for our forthcoming (April 2020) scale-up (mesocosm) experiment.

Another research direction pursued at Bangor related to WP3 was mining for new microbial enzymes that are active towards so-called 'bio-based' polymers, which apparently are poorly biodegradable. We used three species of bio-based polymers, PLA, PHB and a commercial blend used to manufacture coffee cap lids for one of the leading coffee shops chain, to set up microbial enrichment cultures with four samples from hot vents of Ischia island. After incubation, we harvested microbial DNA and established two metagenomic gene libraries that have been screened with general substrates for esterases, the enzymes that may be active on synthetic polyesters. We have identified approx. 50 enzyme candidates, mostly from thermophilic bacteria (Thermus, Geobacillus, etc). These enzymes undergo expression, purification and biochemical characterisation to identify the most efficient ones that could potentially be used in industrial applications.


Extensive model validation is essential for the modelling, and this important task will be carried out in both studied estuaries - the Firth of Forth and the Conwy. This fieldwork is planned to start March 2020 and incorporate data collection at key sites in the river/CSO pipes (microplastic sources) and in each estuary (microplastic sinks). Field campaigns have been designed to cover high temporal resolution, event sampling, and long term seasonal patterns. Fieldwork design is now complete. Data on plastic sources, pathways, sinks and types will be used to inform plastic settling behaviour within the PTM. Realistic simulated current-fields leading up to data collection will then be used to model microplastic transport (i.e. source ? sink). This approach will identify the plastic sinks, which will be cross-checked against the in-estuary data. Through an iterative sensitivity approach that tests parameters (i-iv) above, the simulations will be improved against the data. The validated modelling method will then be used to explore scenarios and storylines that capture the range of plastic dispersal under different environmental and human conditions that lead to human health risk from microbial viruses, identifying likely hotspots of microplastic/virus accumulation.
Exploitation Route to early to say (the project is in its eary stage, however the project results will benefit to policy makers and regulators, both nationally and internationally. The main UK beneficiaries will be, the NHS, Defra Natural Resources Wales, Scottish Environmental Protection Agency), water companies, and NGOs and UK academia.
Sectors Chemicals,Education,Environment,Healthcare,Manufacturing, including Industrial Biotechology

 
Description HEFCW Infrastructure Grant
Amount £163,000 (GBP)
Organisation Higher Education Funding Council for Wales (HEFCW) 
Sector Public
Country United Kingdom
Start 10/2019 
 
Title Model development for the Conwy 
Description Research Tools & Methods Model development for the Conwy We used a tidal model (Telemac Modelling System V7.2; www.opentelemac.org) to simulate circulation and water quality in the Conwy estuary and surrounding coast. The Telemac model was set-up in vertically-averaged mode. The model simulates in space and time the evolution of elevations, water depths, velocities, salinities, temperatures and dispersion of dissolved substances such as nutrients and viruses with or without die-off. Telemac uses an unstructured mesh, which in this case comprised 120,000 nodes connected on an unstructured triangular configuration (Fig. 1). This mesh was mapped on to observational bathymetry data, with varying resolution; being very high within the estuary (~20m) and coarser o?shore (50m-2km). Bathymetry for the Conwy estuary has been attained from the UK Government's ADMIRALTY Marine Data Portal (www.admiralty.co.uk/ukho), as well as in-house (Bangor) surveys within the estuary and LiDAR data from the Environment Agency. Additionally, bathymetry data in the outer estuary and surrounding coast has been attained from Admiralty data products at 200 m spatial resolution (digimap.edina.ac.uk/marine). The model is hydrostatic and based on the depth-averaged shallow water equations of momentum and continuity (Hervouet, 2007), with depth-averaged turbulent mixing (Rastogi and Rodi, 1978). For more information on the model parameterisation, see Robins et al. (2019). For information on model validation, please see Robins et al. (2014). 
Type Of Material Improvements to research infrastructure 
Year Produced 2019 
Provided To Others? Yes  
Impact The Telemac model is well suited to vertically-mixed coastal applications since the mesh can be optimised to adequately resolve coastal features and the model incorporates wetting/drying capabilities of inter-tidal regions. 
 
Description Collabration with the Italian project "Emergence of virulence and antibiotic-resistance vectors in coastal and deep sea marine environments and analysis of the mechanisms and conditions underlying their spread and evolution." 
Organisation Marche Polytechnic University
Country Italy 
Sector Academic/University 
PI Contribution The Italian project was funded in February 2020, in category PRIN: PROGETTI DI RICERCA DI RILEVANTE INTERESSE NAZIONALE by the Italian Ministry of Education, Universities and Research (MINISTERO DELL'ISTRUZIONE, DELL'UNIVERSITA E DELLA RICERCA PROGRAMMI DI RICERCA - ANNO 2020) and will start in March 2020. Expected contibutions are: coordination/synchronisation of sampling campaigns, access to sampling sites and samples' exchange, sharing materials (e.g. plastics blends), coordination on the use of uniform/standartised methodologies in both projects. Co-ordinator, Prof Michail M Yakimov, Institute of Marine Resources and Biotechnology-CNR, Messina
Collaborator Contribution Project is about to start in March 2020. Expected contibutions are: coordination/synchronisation of sampling campaigns, access to sampling sites and samples' exchange, sharing materials (e.g. plastics blends), coordination on the use of uniform/standartised methodologies in both projects
Impact no outputs yet (starts in March 2020)
Start Year 2020
 
Description Collabration with the Italian project "Emergence of virulence and antibiotic-resistance vectors in coastal and deep sea marine environments and analysis of the mechanisms and conditions underlying their spread and evolution." 
Organisation National Research Council
Department Institute for Biological Resources and Marine Biotechnology
Country Italy 
Sector Public 
PI Contribution The Italian project was funded in February 2020, in category PRIN: PROGETTI DI RICERCA DI RILEVANTE INTERESSE NAZIONALE by the Italian Ministry of Education, Universities and Research (MINISTERO DELL'ISTRUZIONE, DELL'UNIVERSITA E DELLA RICERCA PROGRAMMI DI RICERCA - ANNO 2020) and will start in March 2020. Expected contibutions are: coordination/synchronisation of sampling campaigns, access to sampling sites and samples' exchange, sharing materials (e.g. plastics blends), coordination on the use of uniform/standartised methodologies in both projects. Co-ordinator, Prof Michail M Yakimov, Institute of Marine Resources and Biotechnology-CNR, Messina
Collaborator Contribution Project is about to start in March 2020. Expected contibutions are: coordination/synchronisation of sampling campaigns, access to sampling sites and samples' exchange, sharing materials (e.g. plastics blends), coordination on the use of uniform/standartised methodologies in both projects
Impact no outputs yet (starts in March 2020)
Start Year 2020
 
Description Collabration with the Italian project "Emergence of virulence and antibiotic-resistance vectors in coastal and deep sea marine environments and analysis of the mechanisms and conditions underlying their spread and evolution." 
Organisation National Research Council
Department Institute of Marine Sciences
Country Italy 
Sector Public 
PI Contribution The Italian project was funded in February 2020, in category PRIN: PROGETTI DI RICERCA DI RILEVANTE INTERESSE NAZIONALE by the Italian Ministry of Education, Universities and Research (MINISTERO DELL'ISTRUZIONE, DELL'UNIVERSITA E DELLA RICERCA PROGRAMMI DI RICERCA - ANNO 2020) and will start in March 2020. Expected contibutions are: coordination/synchronisation of sampling campaigns, access to sampling sites and samples' exchange, sharing materials (e.g. plastics blends), coordination on the use of uniform/standartised methodologies in both projects. Co-ordinator, Prof Michail M Yakimov, Institute of Marine Resources and Biotechnology-CNR, Messina
Collaborator Contribution Project is about to start in March 2020. Expected contibutions are: coordination/synchronisation of sampling campaigns, access to sampling sites and samples' exchange, sharing materials (e.g. plastics blends), coordination on the use of uniform/standartised methodologies in both projects
Impact no outputs yet (starts in March 2020)
Start Year 2020
 
Description Collabration with the Italian project "Emergence of virulence and antibiotic-resistance vectors in coastal and deep sea marine environments and analysis of the mechanisms and conditions underlying their spread and evolution." 
Organisation University of Genoa
Country Italy 
Sector Academic/University 
PI Contribution The Italian project was funded in February 2020, in category PRIN: PROGETTI DI RICERCA DI RILEVANTE INTERESSE NAZIONALE by the Italian Ministry of Education, Universities and Research (MINISTERO DELL'ISTRUZIONE, DELL'UNIVERSITA E DELLA RICERCA PROGRAMMI DI RICERCA - ANNO 2020) and will start in March 2020. Expected contibutions are: coordination/synchronisation of sampling campaigns, access to sampling sites and samples' exchange, sharing materials (e.g. plastics blends), coordination on the use of uniform/standartised methodologies in both projects. Co-ordinator, Prof Michail M Yakimov, Institute of Marine Resources and Biotechnology-CNR, Messina
Collaborator Contribution Project is about to start in March 2020. Expected contibutions are: coordination/synchronisation of sampling campaigns, access to sampling sites and samples' exchange, sharing materials (e.g. plastics blends), coordination on the use of uniform/standartised methodologies in both projects
Impact no outputs yet (starts in March 2020)
Start Year 2020
 
Description "Activity-Based Bioprospecting for Hydrolases In Enrichment Cultures from Thermal Vents of Ischia Island (Italy)" Oral presentation 15th International Congress on Thermophiles, "Thermophiles-2019" Fukuoka, Japan, September 2-6, 2019. 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Oral presentation at a very important International Congress, attended by approx 300 researchers from across the world. Few important links established (e.g. with researchers from Institute Pasteur and Unis of Fukuoka, Naples and Tokyo), existing collaborations fostered (e.g. NCBI/NLM/NIH, Universities of Bergen, Vienna and Copenhagen).
Year(s) Of Engagement Activity 2019
URL http://www.acplan.jp/thermophiles2019/
 
Description "Bioprospecting for new enzymes in petroleum-degrading microorganisms", Oral presentation at the Environmental Biotechnology Network (EBNet) Research Colloquium Edinburgh, January 22-23, 2020 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact Oral presentation at the event organised by Environmental Biotechnology Network (EBNet, BBSRC-funded) Colloquium Edinburgh, attended by >60 academics, industry and science-funding bodies. Important discussions on harnessing microbial processes to mitigate petroleum and plastics pollution in marine environment
Year(s) Of Engagement Activity 2020
URL https://ebnet.ac.uk/ebnetrc2020/
 
Description "Marine petroleum-degrading microorganisms, their ecology and applications", Keynote presentation at the Seminar, Biodiversity and applications of marine microorganisms and their enzymes, Catholic University of Valencia, March 5, 2019 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Postgraduate students
Results and Impact Keynote presentation at the Seminar, Biodiversity and applications of marine microorganisms and their enzymes, Catholic University of Valencia, attended by approx 90 masters and teaching staff, students, promoted lively discussion on various applications of enzymes from petroleum-degraading microorganisms, including plastics conversion
Year(s) Of Engagement Activity 2019
 
Description School of Natural Sciences, Bangor University Open Days for perspective undergraduate students (three times per semester) 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Other audiences
Results and Impact The Open Days are organised by Bangor University to attract prospective students (and their family members) to enthuse with environmental and biotech research. In our laboratories, we demonstrated research facilities and explain our ongoing projects. Approximately 20 students and their family members (per visit) take part in conversations and express their interest in our science (approx 120 p.a.)
Year(s) Of Engagement Activity 2019,2020
 
Description Visit of Agilent Technologies Centre in Didcot 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Industry/Business
Results and Impact Profs Davey Jones and Peter Golyshin visited Agilent Technologies campus in Didcot to acquire knowledge on and having a demonstration of the new plastics analysis platform, Agilent LDIR 8700
Year(s) Of Engagement Activity 2019
 
Description visit of Tecan campus in Reading 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Study participants or study members
Results and Impact Two team members visited the Tecan campus in Reading to learn and expand their skills in programming and operating the liquid handling/colony picking robot Tecan Freedom Evo
Year(s) Of Engagement Activity 2019