The regulation of rhamnolipid biosynthesis in Burkholderia thailandensis.

Summary

Microbial biosurfactants, such as the rhamnolipids produced by Burkholderia thailandensis, have been identified as surface active agents which may have extensive application in a wide range of consumer products. Some of these biosurfactants such as sophorolipids have already found their way to the market place, however, rhamnolipids have yet to make an impact since the best producer organism is a human pathogen. B. thailandensis is an alternative non-pathogenic producer which is being investigated. The key problem to be overcome with biosurfactant production is the low yield of product and the consequent poor economics of the process. A clear knowledge of the regulation of production is therefore essential to achieve high productivity and an economic process.

The focus of this project will therefore be to examine the genetic regulation of rhamnolipid production in B. thailandensis principally through the use of knockout mutants of the key production enzymes. This organism has two identical operons containing the relevant genes but the contribution and regulation of these two operons is not known. A library of knockout mutants is available, but some of the key mutants are not contained in the library, it will therefore be necessary to produce in-house additional mutants to complete the study. The availability of a complete genome sequence will facilitate this approach. QRT-PCR will be the initial tool to examine the expression of the two operons at different times and under different conditions during growth.

Applicants should note that bench fees of £2000.00 per year are required.

Related References:

S. Funston, K. Tsaousi, M. Rudden, TJ. Smyth, PS. Stevenson, R. Marchant and IM. Banat (2016).  Characterising rhamnolipid production in Burkholderia thailandensis E264,, a non-pathogenic producer. Appl. Microbiol & Biotechnol. 205: 1-6. 10.1007/s00253-016-7564-y

S. Funston, K. Tsaousi, T. J. Smyth, M. S. Twigg, R. Marchant and I.M. Banat (2017). Enhanced rhamnolipid production in Burkholderia thailandensis transposon knockout strains deficient in polyhydroxyalkanoate (PHA) synthesis. Applied Microbiology and Biotechnology, 101 (23), 8443-8454. DOI: 10.1007/s00253-017-8540-x

Essential criteria

• To hold, or expect to achieve by 15 August, an Upper Second Class Honours (2:1) Degree or equivalent from a UK institution (or overseas award deemed to be equivalent via UK NARIC) in a related or cognate field.

Funding

This is a self-funded PhD opportunity.