Looking for plastic biodegraders in submarine hydrothermal ecosystems
This research project is in competition for funding with one or more projects available across the NERC GW4 Doctoral Training Partnership (DTP). Usually the projects which receive the best applicants will be awarded the funding. Find out more information about the DTP and how to apply.
Application deadline: 7 January 2019
Start date: October 2019
DTP research theme: Living World, Changing Planet
Do hydrothermal microorganisms and their enzymatic machineries hold the capacity to promote complete plastic biodegradation? If so, who are they and how efficient are their activities compared to previously investigated microbial systems?
These questions remain essentially unanswered because much work on the potential for microorganisms to biodegrade plastics has focused mainly on the soil microbiota. In addition to the fact that there exists little or no research on the ability of hydrothermal microorganisms to degrade plastics, their capacity to thrive under the vast geochemical gradients, high temperatures and extreme pH that characterise hydrothermal ecosystems, may benefit the selection of efficient plastic biodegraders.
Moreover, potential abiological breakdown of plastics by oxidative processes, partial depolymerisation and the catalytic activity of metal oxides plentiful in hydrothermal ecosystems towards plastics is an unknown. Combined with the elevated temperatures associated with the growth of thermophiles and hyperthermophiles, these processes may naturally generate smaller and easily metabolized products that will benefit the enrichment of efficient plastic degrading microorganisms in hydrothermal habitats.
The proposed study is part of an international collaboration initiative between the School of Earth and Ocean Sciences, Cardiff University and the Department of Geosciences and Natural Resource Management, University of Copenhagen, Denmark. It is linked to the new plastisphere project run by Dr Nicole Posth at Copenhagen University.
Project aims and methods
The proposed project will screen a range of hydrothermal microorganisms existing in the German and American type culture collections for their potential to biodegrade a variety of plastics with different compositions and applications.
Microorganisms will be cultured and their ability to degrade plastics from various commercial suppliers evaluated by investigating gene activity levels and identifying the key genes and proteins involved, linked to physical and chemical environmental factors, their metabolisms and nutrient sources.
These data will be used to assess the prevalence and activity of such genes in near-shore active shallow submarine hydrothermal sediments collected at a maximum depth of 12 m below sea level. The shallow submarine ecosystems on the shores of Milos Island, Greece are vulnerable to plastic contamination because of close proximity to intense summer recreational beaches.
They will be studied by “omics” methods for whole microbial community and genetic composition, related to in situ gene activity levels. Specific goals are to unravel the genetic factors and metabolic pathways involved in plastic biodegradation that can be adopted and transformed for biotechnological applications. These include the biodegradation of plastics before they are released into the environment and bioremediation of plastic contaminated sites.
We seek a candidate with interest in developing the next generation biotechnology applications for a green Earth. This individual should have a proven background or interest in biology, microbiology or biotechnology, with a readiness to undertake interdisciplinary research linking these aspects.
The research will be conducted as an international collaboration between Cardiff University and Dr Nicole Posth at the University of Copenhagen, Denmark
You will acquire skills in cutting edge environmental molecular biology techniques, including instrument and data analyses skills for gene quantification and identification. Experience will be gained in aerobic and anaerobic culturing of microorganisms using different equipment and the analysis of metabolic biopolymers as proxies.
Opportunities are available for attending and presenting work at international conferences, workshops and training at summer schools. You will interact with an international research team working on plastic biodegradation at the University of Copenhagen, where they will gain new real-world experiences and skills in the design of new methods and instrumentations for testing biogeochemical processes associated with water column and sediment biodegradation of plastics.
References and background reading list
- Shah AA et al., 2008. Biological degradation of plastics: A comprehensive review. Biotechnology Advances, 26:246-265.
- Sivan A. 2011. New perspectives in plastic biogradation. Current Opinion in Biotechnology, 22:422-426.
- Emadian SM, Onay TT, Demirel B. 2017. Biodegradation of bioplastics in natural environments. Waste Management 59:526-536.
- Gewart B, Plassmann MM, MacLeod M. 2015. Pathways for degradation of plastic polymers floating in the marine environment. Environmental Science Processes & Impacts, 17;1512, doi:10.1039/c5em00207a.
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