PhD Study : An Investigation of The Bacteriostatic and Bacteriocidal Modes of Action of Biosurfactants on Various Bacteria.

Summary

Microbial biosurfactants have been investigated extensively in the last few years as alternatives to chemical surfactants in a wide range of commercial products including personal care products, such as toothpaste, shampoos, skin cleansers and detergent products. These biosurfactants as well as possessing surface activity have been shown to have other bioactivity including anti-cancer properties and importantly antibacterial activity against a range of bacterial species.

These effects include growth inhibition (bacteriostatic) and killing (bacteriocidal) activities against various bacteria. There has been little investigation of the mode of action of microbial biosurfactants against other organisms with the assumption being made that the effects are produced by direct interaction of the surfactants with the cell membrane. In this project the aim will be to elucidate the mechanism(s) of action of several microbial low molecular weight biosurfactants on a range of different bacterial species, both Gram negative and Gram positive.

The objectives of the project will be:

1.To define how the bacteriostatic and bacteriocidal properties of biosurfactants are expressed against different types of bacteria.

2.To investigate whether the effects are due to a direct interaction with the cell membrane leading to cell damage and leakage of materials from the cell.

3.To determine whether susceptible bacterial species are affected uniformly throughout their growth cycle or whether the stage of growth determines the extent of the effect.

4.To examine, through the use of molecular biology techniques, whether the biosurfactants have any direct effect on the metabolism of the cells through changes in gene expression.

The investigative methods to be used in this study will involve the use of standard microbial culture methods, to demonstrate growth and killing effects. These methods will be supplemented with specific staining methods and various analytical methods to determine the damage caused to the cells.

Direct microscopic observation will also play an important role. The effect of the surfactants on the metabolism of the cells will be examined through the use of qRT PCR to quantify the expression of key regulated metabolic genes which will give us indications into key metabolic functions impairments or inhibitions.

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.

• Sound understanding of subject area as evidenced by a comprehensive research proposal

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
• Practice-based research experience and/or dissemination
• Experience using research methods or other approaches relevant to the subject domain
• Work experience relevant to the proposed project
• Publications - peer-reviewed
• Experience of presentation of research findings
• A comprehensive and articulate personal statement
• Relevant professional qualification and/or a Degree in a Health or Health related area

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