PhD Study : Ecological impacts of biological and chemical surfactants on aquatic biofilm growth metabolism and carbon cycling (EcoSurf)

Summary

Surfactants are chemicals that adsorb at the interface of a liquids, allowing it to foam or penetrate a solid. Surfactants such as sodium lauryl sulphate have a range of domestic and industrial applications, such as detergents. Consequently, surfactants represent a significant component of human wastewater, yet their removal by wastewater treatment plants is inefficient. In inland waters, microbial life is dominated by biofilms attached to surfaces and aggregates (“river snow”) suspended in the water column1.

Both are composed of microbial cells embedded within an extracellular polysaccharide (EPS) matrix. Biofilms and aggregates exist on a continuum, with aggregates formed through the erosion of streambed biofilms1, whilst biofilms trap aggregates regulating, their transport downstream2,3. Biofilm dwelling microorganisms produce biosurfactants, such as rhamnolipid and sophorolipids, to alter biofilm structure and permeability. Biosurfactants, thus, control a biofilm’s resistance to erosion, its ability to trap and retain particles and capacity for dissolved gas and nutrient exchange.

There is growing interest from the chemical industry regarding the potential of biosurfactants to provide environmentally friendly alternatives to chemical detergents. Biosurfactants are capable of being biologically degraded, and tend to have lower toxicity to aquatic fauna4. In addition, given their capacity to influence biofilm structure, biosurfactants exhibit potential as antifouling treatments for boat hulls and submerged structures5.

To accurately assess their potential benefits as industrial and domestic detergents, however, we must test how biosurfactants affect the structure and functioning of complex aquatic biofilms.

The EcoSurf project will seek to elucidate how chemical and biological surfactants affect

i)the formation and structure of streambed biofilms,

ii)interactions between streambed biofilms and suspended microbial aggregates within streamwater

iii)biofilm metabolism and carbon cycling.

This requires a multidisciplinary approach combining methods from aquatic ecology, eco-hydrology, microbial ecology and molecular biology. This requires a multidisciplinary approach combining methods from aquatic ecology, eco-hydrology, microbial ecology and molecular biology.

The student will be supervised by Dr Billy Hunter, from the School of Geography and Environmental Science who has specific expertise in investigating the impacts of environmental change upon aquatic biofilms; Professor Ibrahim Banat in the School of Biomedical Sciences, who has specific expertise in the production of microbial biosurfactants’ and their biotechnological and industrial application; and Dr Joerg Arnscheidt, a Senior Lecturer in Earth Systems Science from the School of Geography and Environmental Science with expertise in water quality monitoring and aquatic ecology.

The project will also include international collaboration with Dr Jakob Schelker at the University of Vienna’s Department of Limnology and Bio-Oceanography, University of Vienna.

Through this collaboration, the student will have access to the internationally excellent experimental mesocosm facilities at the Austrian Interuniversity Centre for Aquatic Ecosystem Research (WCL http://www.wasserkluster-lunz.ac.at) which is a globally recognised centre of excellence for water research. The WCL has supported research leading to over 200 publications in leading journals (including Nature; Nature Geoscience; ISME Journal; and the Proceedings of the National Academy of Sciences) over the past 10 years and is the partner in the pan-European Aquacosm network of environmental research facilities (www.aquacosm.eu).

References

¹Battin et al. (2003). Nature, 426: 439–442

²Hunter et al. (2016). Geophys. Res. Lett., 43, doi:10.1002/2016GL067719.

³Roche et al. (2017). Water Resour. Res., 53, doi:10.1002/2016WR019041.

⁴Banat et al.(2014). Applied Microbiology and Biotechnology, 98: 9915–9929. DOI: 10.1007/s00253-014-6169-6.

⁵Chebbi et al. (2017). Journal of Basic Microbiology  9999:1-12.  DOI 10.1002/jobm.201600658.

Essential criteria

Applicants should hold, or expect to obtain, a First or Upper Second Class Honours Degree in a subject relevant to the proposed area of study.

We may also consider applications from those who hold equivalent qualifications, for example, a Lower Second Class Honours Degree plus a Master’s Degree with Distinction.

In exceptional circumstances, the University may consider a portfolio of evidence from applicants who have appropriate professional experience which is equivalent to the learning outcomes of an Honours degree in lieu of academic qualifications.

• A comprehensive and articulate personal statement

Desirable Criteria

If the University receives a large number of applicants for the project, the following desirable criteria may be applied to shortlist applicants for interview.

• First Class Honours (1st) Degree
• Masters at 65%
• Research project completion within taught Masters degree or MRES
• Experience using research methods or other approaches relevant to the subject domain
• Work experience relevant to the proposed project
• Experience of presentation of research findings

Funding and eligibility

The University offers the following levels of support:

Vice Chancellors Research Studentship (VCRS)

The following scholarship options are available to applicants worldwide:

• Full Award: (full-time tuition fees + £19,000 (tbc))
• Part Award: (full-time tuition fees + £9,500)
• Fees Only Award: (full-time tuition fees)

These scholarships will cover full-time PhD tuition fees for three years (subject to satisfactory academic performance) and will provide a £900 per annum research training support grant (RTSG) to help support the PhD researcher.

Applicants who already hold a doctoral degree or who have been registered on a programme of research leading to the award of a doctoral degree on a full-time basis for more than one year (or part-time equivalent) are NOT eligible to apply for an award.

Please note: you will automatically be entered into the competition for the Full Award, unless you state otherwise in your application.

Department for the Economy (DFE)

The scholarship will cover tuition fees at the Home rate and a maintenance allowance of £19,000 (tbc) per annum for three years (subject to satisfactory academic performance).

This scholarship also comes with £900 per annum for three years as a research training support grant (RTSG) allocation to help support the PhD researcher.

• Candidates with pre-settled or settled status under the EU Settlement Scheme, who also satisfy a three year residency requirement in the UK prior to the start of the course for which a Studentship is held MAY receive a Studentship covering fees and maintenance.
• Republic of Ireland (ROI) nationals who satisfy three years’ residency in the UK prior to the start of the course MAY receive a Studentship covering fees and maintenance (ROI nationals don’t need to have pre-settled or settled status under the EU Settlement Scheme to qualify).
• Other non-ROI EU applicants are ‘International’ are not eligible for this source of funding.
• Applicants who already hold a doctoral degree or who have been registered on a programme of research leading to the award of a doctoral degree on a full-time basis for more than one year (or part-time equivalent) are NOT eligible to apply for an award.

Due consideration should be given to financing your studies. Further information on cost of living