EASTBIO: Microplastics as degraders of soil biological habitat

This fully funded, 4-year PhD project is part of a competition funded by the BBSRC EASTBIO Doctoral Training Partnership.

Microplastics are more prevalent in soils than any other ecosystem, with Europe alone applying more microplastics to land than affects all the world’s oceans in a year. Agricultural soils are particularly affected by plastic mulches or microplastics present in amendments such as compost. When plastics degrade, the fragments and fibres that develop into microplastics have different impacts on soil, including mechanical enmeshment that aggregate particles and hydrophobic surfaces that repel water. It may be that microplastics create weaker pathways for plant root growth in soil, creating hot spots of microbial activity where it may be less desirable. Microorganisms in soil close to microplastics form a ‘plastisphere’ where the changed physical habitat may have a bigger impact than direct toxicity. The diversity of microorganisms, and their capacity to stabilise soils or support plant growth by cycling nutrients, becomes impaired by microplastics, resulting in poorer quality soils. Microorganisms may also have a decreased capacity to adhere to soil particles, so more pathogens and antagonists may flow with pore water, with implications to microbial competition, plant diseases and human health.

This PhD project will explore how microplastics affect soil microbial habitat, linking changes to soil pore structure and surface properties to microbial communities. Novel approaches developed by the supervisory team will be applied to quantify how microplastics affect the interfacial properties of soil, including the affinity for water absorption, stability and microbial adhesion. Advanced molecular approaches such as high-throughput amplicon sequencing will be applied to quantify how microplastics change microbial communities and their functional capacity to cycle nutrients and stabilise soils.

Objectives:

1. To quantify microplastic impacts to soil pore structure, water dynamics and mechanical binding due to interfacial properties.
2. To quantify microplastic impacts to microbial community dynamics and their functional capacity to cycle nutrients and stabilise soils.
3. To bridge the understanding of how microplastics affect the biophysical properties of microbial habitats (Obj. 1) with the impacts to microorganisms (Obj. 2).

The project would include controlled laboratory experiments that amend soils with varying concentrations of different types and sizes of microplastics. This approach offers a range of potential variables to explore including microplastic distribution and location, different soils, and stresses such as drought, temperature or other emerging contaminants. Field investigations will explore microplastic experiments established by the James Hutton Institute and would include longer-term impacts, using microplastic gradients from compost and livestock waste amendment. 

For further project information please contact the lead project supervisor by selecting the first listed name at the top of this advert and sending your enquiry.

---------------------------------

ELIGIBILITY:

Applicants should hold a minimum of a 2:1 UK Honours degree (or international equivalent) in a relevant subject. Those with a 2:2 UK Honours degree (or international equivalent) may be considered, provided they have (or are expected to achieve) a Distinction or Commendation at master’s level.

We encourage applications from all backgrounds and communities, and are committed to having a diverse, inclusive team.

All students must meet the eligibility criteria as outlined in the UKRI guidance on funding for postgraduate training and development. This guidance should be read in conjunction with the Terms and conditions for training funding – UKRI.

---------------------------------

APPLICATION PROCEDURE:

• Please visit this page for full application information: https://biology.ed.ac.uk/eastbio/how-to-apply
• Please send your completed EASTBIO application form, along with academic transcripts and certificates to [Email Address Removed]
• Please ensure that two references are submitted by the deadline using the EASTBIO reference form (available here). If the references are not included with your application, they must be sent directly to [Email Address Removed] with the subject line: "EASTBIO Reference – [Your Name]".
• It is the applicant’s responsibility to ensure that references are submitted by the deadline (17^th January). We will not request academic references on your behalf.
• Please ensure you submit all the required information and documentation. Due to workload constraints, we are unable to follow up on missing documents or process incomplete applications.
• If you require any additional assistance in submitting your application or have any queries about the application process, please don't hesitate to contact us at [Email Address Removed]