Prior to joining Chemical Engineering, Dr Overton was a postdoctoral researcher in the School of Biosciences at the University of Birmingham, studying microbial physiology and gene regulation in both model organisms (Escherichia coli) and human pathogens (Neisseria gonorrhoeae and E. coli O157) in response to oxygen and reactive species using transcriptomic, proteomic and other molecular biology techniques. Using systems biology and other molecular approaches, he identified mechanisms for bacterial survival in adverse environments. 

Research became focused on bioprocessing topics during a BBSRC-EPSRC Bioprocessing Research Industry Club (BRIC) grant in collaboration with GSK, studying the production of difficult recombinant proteins in E. coli. Dr Overton was initially postdoctoral researcher on this project, and moved to a Co-I role upon taking up his position in the School of Chemical Engineering. 

He has since built a research group focused on three main areas: production of high-value products using microbial fermentation; bacterial biofilms and how to use them to produce useful products or to remove them from where they are not desired; and how microbes can be eliminated from various processing streams. Research areas are further detailed below.

Dr Overton is director of MSc programmes in the School of Chemical Engineering and chairs the School MSc and EngD board of examiners. He is a member of the University Advisory Group on Biological Hazards and is School GMO safety officer and a member of the School safety committee. He is a member of BBSRC research committee D, reviews for research councils (BBSRC, EPSRC, MRC) and other funding bodies (Carnegie Trust of Edinburgh, NSF, National Biofilms Innovation Centre) and journals.

Research is split into three main themes. Throughout each stream we are interested in applying microbial physiology to solve real-world problems and optimise processes. We work closely with industry to do this.

Fermentation for useful products

Microbes are used for the production of many high-value products in fermentation processes. We investigate how these processes might be improved and optimised, to increase yields, shorten development times and accelerate innovation in bioproduction. Research has focused on a variety of product types.

• Recombinant proteins for biopharmaceutical use, manufactured in E. coli as a host. Research focuses on hard-to-manufacture proteins, stress minimisation, fermentation intensification, analysis of physiology in real time and transport of proteins to the periplasm (funded by BBSRC / EPSRC / InnovateUK KTP and in collaboration with industry). 

• Biopolymers for replacement of petrochemically-derived plastics, made in C. necator. We are interested in improving polymer properties, measuring gene regulation during processes, and improving extraction of biopolymers using green approaches (funded by EU FP7 / BBSRC PhD studentship and in collaboration with industry). 

• Magnetic nanoparticles are naturally generated by magnetotactic bacteria and allow them to sense the earth’s magnetic field. We are interested in engineering and manufacturing these particles for use in biotechnology and bioprocessing applications (funded by ERA-IB / BBSRC and in collaboration with industry).

Bacterial biofilms

Bacteria form biofilms, communities of cells immobilised onto surfaces by secreted polymeric substances, in many settings. Biofilms are typically tough and resistant to both physical removal and chemical treatment. This causes a problem in clinical and industrial settings, but we are also interested in how biofilms can be used as tough biocatalysts for production of fine chemicals. Within this area we investigate several approaches to understand how biofilms form and how we can interact with them.

• We demonstrated that E. coli biofilms are tough and efficient biocatalysts for the production of pharmaceutical precursor molecules. We are interested in implementing biofilms as a platform for biocatalysis (funded by BBSRC). 

• There is growing evidence that mechanosensing is an important part of biofilm formation. We are studying how mechanosensing influences the formation and development of E. coli biofilms (funded by BBSRC PhD studentship). 

• The development of E. coli biofilms also relies upon sensing of physicochemical cues; understanding how these impact on biofilm formation and development is essential to understanding and preventing biofilm formation. 

• In collaboration with Procter & Gamble we are working on biofilms in industrial settings, how to prevent their formation and how to remove biofilms that have already formed (funded by EPSRC CDT scheme). 

• We are interested in novel approaches to biofilm formation, including using polymers to nucleate and drive biofilm generation (funded by BBSRC PhD studentship).

Microbes in processing streams   

Microbes are ubiquitous in nature, but it is essential that they are removed from the processing streams for a variety of products such as food and fast-moving consumer goods. We are interested in developing processes that remove microbes from these settings.

• In collaboration with Colgate-Palmolive we are studying production of formulated products to improve robustness of formulations (funded by EPSRC CDT scheme).

• Dairy processing requires removal of pathogens from milk to ensure product safety, but generates large quantities of waste materials. We developed methods to process waste streams to generate added value (funded by InnovateUK and in collaboration with industry).

• PGCert in Learning & Teaching in HE, University of Birmingham, 2012
• PhD in Biochemistry, University of Birmingham, 2003
• BSc (Hons) in Biochemistry with Molecular and Cell Biology, University of Birmingham, 1999