PhD Research Project: Tailored biopolymer production from waste streams: low-cost value added biopr

United Kingdom
Jan 16, 2018
Apr 09, 2018
Organization Type
University and College
Full Time

Biopolymers are a growing research area, required due to the increasing problems posed by petrochemically-derived plastics. One such class of biopolymers, polyhydroxyalkanoates (PHAs), are naturally generated by many species of bacteria as a carbon and energy store. PHAs can be generated from a range of naturally-occurring non-petrochemical feedstocks and are readily biodegradable.

However, PHAs currently face several problems before they can be implemented as a replacement for conventional plastics in manufacturing processes. The most commonly-found PHA, poly-3-hydroxybutyrate (P(3HB)) is brittle and becomes more brittle over time, a phenomenon caused by high crystallinity. PHAs are also expensive to produce when compared to oil-based plastics, and their processing typically requires large quantities of environmentally harmful organic and halogenated solvents.

In order to solve these three problem areas and allow PHAs to be used commercially, this project will aim to:

  1. Investigate methods by which crystallinity can be decreased. Previous work in Birmingham has focused on supply of alternative monomer feedstocks for PHA production; this project will continue this approach while also exploring strain engineering to specify PHA structure and functionality.
  2. Generate PHAs from waste feedstocks such as waste glycerol from biodiesel manufacture. Waste glycerol is very cheap (or free) and available in large quantities; biodiesel companies currently pay for its disposal, so biorefinery of this waste stream would represent added value and decrease environmental impact.
  3. A novel method of PHA extraction and purification has been developed in Birmingham. This will be refined and complemented by wholly aqueous, mechanical and enzyme-based extraction technologies. In each case, the mechanism of PHA release will be determined at the bacterial scale and the impact of release method on PHA properties will be tested.

The project will straddle industrial microbiology and materials science research, in order to generate a relatively high-value product from low-value waste materials. The project will combine molecular microbiology (strain engineering), industrial microbiology (fermentation, cell harvest and disruption, PHA isolation and purification) and material science (polymer testing using differential scanning calorimetry, size exclusion chromatography and NMR).

Excellent students are invited to apply, with an Undergraduate Honours degree with a minimum classification of a 1st or equivalent and an English Language qualification for international students. Applicants should have a biosciences, chemical engineering, bioengineering, biotechnology or chemistry background and be interested in interdisciplinary research.

Please contact Dr Tim Overton with your CV by email:


Funding Notes

Details on funding opportunities are available through the PG Funding Database:



Verlinden, R.A., Hill, D.J., Kenward, M.A., Williams, C.D. and Radecka, I.: Bacterial synthesis of biodegradable polyhydroxyalkanoates, J. Appl. Microbiol., 102, 1437-49 (2007).
Chen (2010) Plastics Completely Synthesized by Bacteria: Polyhydroxyalkanoates. In Plastics from Bacteria: Natural Functions and Applications, Chen (ed.). Microbiology Monographs 14: 17-37

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