PhD Study : Investigation of the diversity and role of rhamnosyltransferase enzymes in rhamnolipid synthesis in bacteria.

Summary

Rhamnolipids have been identified as microbial biosurfactants with huge potential for industrial exploitation, however, the best known producer, Pseudomonas aeruginosa is a human pathogen and therefore unacceptable as an industrial organism. A number of other non-pathogenic bacterial producers of rhamnolipid have been identified and these are currently being intensively researched.  All these bacteria yield a mixture of mono-rhamnolipids and di-rhamnolipids in different proportions since the mono form provides the substrate for a second rhamnosyltransferase to add the second sugar molecule to produce the di form.

It is this second rhamnosyltransferase that will form the focus for this project since it controls the proportion of mono to di-rhamnolipid in the final product. The approach in this project will be to use our existing knowledge of the gene sequences of this enzyme from different organisms to give heterologous expression in E.coli  of a his-tagged protein which can then be purified. Having a purified enzyme will allow protein sequencing to be carried out by mass spectrometry and the development of a cell free enzyme assay to determine the kinetics of each of the rhamnosyltransferases.

Applicants should note that Bench fees of £2000.00 are required.

Related references:

V. U. Irorere, L. Tripathi, R. Marchant, S. McClean and I. M. Banat (2017). Microbial Rhamnolipid Production: A Critical Re-evaluation of Published Data and Suggested Future Publication Criteria. Applied Microbiology & Biotechnology. 101:3941–3951.   DOI 10.1007/s00253-017-8262-0

Dulcey, Carlos Eduardo; de los Santos, Yossef Lopez); Deziel, Eric ; Doucet, Nicolas. (2017). Semi-rational evolution of the Pseudomonas aeruginosa Rhamnosyltransferase 1 subunit A (RhlA) for the synthesis of industrially relevant rhamnolipids. Protein Science,  26:  68-68.

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.

Funding and eligibility