Polymer industry waste, can microbes degrade it?

Lead Research Organisation: University of Warwick
Department Name: School of Life Sciences

Abstract

Anthropogenic pollution by industrial waste is both ubiquitous and well-characterised. An area of this that has recently received increasing attention is ocean plastic pollution. Pollution of the oceans by synthetic polymers, such as plastics, is now widespread and current estimates put the annual input of plastic waste into the ocean at 4.8 to 12.7 million tons. Much of this plastic waste is known to exist as microplastics (plastics <5 mm). Microplastics may enter the ocean via a number of routes, for example: i) accidental release during the manufacturing process of larger plastics (plastic resin pellets); ii) plastics specifically manufactured to be small (i.e. in facial cleansers/exfoliators); or iii) breakdown of larger plastics.
Bacterial strains that are capable of the degradation of plastics have been isolated from environmental samples, however, it has been found previously that a bacterial consortia, or community, may be better at degrading plastic than an individual strain. Artificial selection - the application of a pressure on organisms to induce the expression of desirable traits - has been used to evolve bacterial communities that are better able to breakdown contaminants than their environmental counterparts.
The project will focus on evolving a microbial community for the degradation of synthetic polymers and characterising the communities that are evolved. The aim of this is to determine whether an artificially evolved microbial community may be better at degrading polymers than either the original environmental community or individual bacterial strains known to be capable of polymer degradation.

Studentship Projects

Project Reference Relationship Related To Start End Student Name
BB/M01116X/1 01/10/2015 30/09/2023
1643043 Studentship BB/M01116X/1 05/10/2015 30/09/2019 Robyn Wright
 
Description The aim of this project is to determine whether marine microorganisms can degrade polymer industry waste, such as plastics and also plasticisers. The method that has been applied for this is artificial selection of microbial communities for polymer degradation. An initial 'proof of concept' experiment has been carried out using the natural polymer, chitin. Chitin is already known to be degraded by a wide range of marine microorganisms, and high throughput enzyme activity assays already exist to test the potential for communities to degrade chitin. This experiment showed that it is possible to artificially select microbial communities for polymer degradation, but that microbial community structure must be taken into consideration; if left for too long, community succession leads to non-optimal communities. When this method was applied to the common packaging plastic, polyethylene terephthalate (PET), we found that the amount of time needed for growth of these microbial communities between selection events meant that this method was not feasible. We therefore instead characterised the microbial community that was growing with PET at different time points, finding that there were bacteria present that were potentially capable of PET degradation. I then moved on to identify the enzymes and pathways used by these bacteria for PET degradation, using a multi-OMIC approach. The third part of my PhD thesis was to identify bacteria capable of the degradation of plastic additives, plasticisers. I isolated 42 bacteria capable of growth with one or more plasticizer, and then used two of these bacteria to characterise the enzymes and pathways used by marine bacteria for plasticizer degradation for the first time. This revealed that different bacteria may use different pathways for this degradation, but the bacteria that are currently colonising marine plastics are capable of plasticizer degradation.
Exploitation Route The artificial selection method that I have used and developed has not previously been used for polymers, so others may use it for a wide range of polymers.
Sectors Aerospace, Defence and Marine,Environment,Manufacturing, including Industrial Biotechology

URL https://pubs-acs-org.ezproxy.library.dal.ca/doi/abs/10.1021/acs.est.9b05228
 
Description Findings were used to help inform a public science engagement evening aimed at increasing awareness of plastic pollution and strategies to help mitigate the impact of it.
First Year Of Impact 2018
Sector Education
Impact Types Cultural,Societal

 
Description Microbiology Society Travel Award
Amount £250 (GBP)
Organisation Microbiology Society 
Sector Learned Society
Country United Kingdom
Start 04/2019 
End 04/2019
 
Description Society Conference Grants
Amount £250 (GBP)
Funding ID SCG17/433 
Organisation Microbiology Society 
Sector Learned Society
Country United Kingdom
Start 04/2017 
End 04/2017
 
Title Genome sequence 
Description Genome sequence for Halomonas sp. ATBC28 
Type Of Material Database/Collection of data 
Year Produced 2019 
Provided To Others? Yes  
Impact N/A 
URL https://www.ncbi.nlm.nih.gov/bioproject/?term=PRJNA525098
 
Title Genome sequence 
Description Genome sequence for Mycobacterium sp. DBP42 
Type Of Material Database/Collection of data 
Year Produced 2019 
Provided To Others? Yes  
Impact N/A 
URL https://www.ncbi.nlm.nih.gov/bioproject/?term=PRJNA525197
 
Title Sequencing data 
Description Data to go with published study: Understanding Microbial Community Dynamics to Improve Optimal Microbiome Selection 
Type Of Material Database/Collection of data 
Year Produced 2018 
Provided To Others? Yes  
Impact N/A 
URL https://www.ncbi.nlm.nih.gov/bioproject/PRJNA499076
 
Description Article written for Biological Sciences Review 
Form Of Engagement Activity A magazine, newsletter or online publication
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Schools
Results and Impact Invited magazine article titled: Marine Bacteria and the Plastisphere for A Level Biology magazine the Biological Sciences Review. This has led several A Level Biology students to contact me, asking for help with their A Level Extended Project Qualification, university applications, finding summer research placements as well as invitations to talk at schools about marine plastic pollution (although I was unable to do this due to having moved to Canada, I was able to put this student in touch with someone else still in the UK).
Year(s) Of Engagement Activity 2019
URL https://www.hoddereducation.co.uk/biologicalsciencesreview
 
Description Oceans Open Evening 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact An oceans open evening was organised and advertised to the general public. This included approximately 45 minutes of presentations on the importance of the oceans, and in particular marine microorganisms, and then the dangers of plastic pollution. This was followed by approximately 1.5 hours of laboratory tours and informal discussion at interactive stands.
Year(s) Of Engagement Activity 2017