Dr Tim Overton BSc PhD

Dr Tim W Overton

School of Chemical Engineering
Reader in Microbial Biotechnology

Contact details

School of Chemical Engineering
University of Birmingham
B15 2TT

Dr Tim Overton is a biochemist and molecular microbiologist who is interested in applying molecular biology and single-cell techniques to understand and develop bioprocesses. He is active in microbial flow cytometry research and collaborates widely with bioprocess engineers, molecular microbiologists, cell biologists and environmental microbiologists to develop new methods of answering fundamental questions on a single-cell level.

His research also focuses on using bacteria to make useful products such as protein drugs and small molecules, and the bacterial responses to stress encountered in such processes. Current and recent research funding has come from the BBSRC, TSB and EU FP7. 


  • 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


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.


Teaching topics include basic biology and molecular biology, systems and synthetic biology, genomic technologies, fermentation and cell culture and analysis of microbial physiology. Dr Overton also supervises fermentation practicals at laboratory and pilot scale (~100 litres).

Postgraduate supervision

We are interested in using information about the molecular microbiology and physiology of bacteria to develop processes. We focus on three main areas:

- Development of bioprocesses that generate high-value products (for example recombinant protein biopharmaceuticals, polymers, small molecules);
- Understanding biofilms and they ways in which their structure and function are regulated and might be modulated; and
- Developing processes that are designed to eliminate contaminating bacteria from product streams (for example foods and waste streams).


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). 
  • Recycling of vehicle batteries using bioleaching approaches. As part of the Faraday Institution-funded ReLiB project, we are interested in using microbes to selectively release metals from spent batteries so that they might be recovered and reused in a green manner. 
  • 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).

Other activities

  • Member of the European Federation of Biotechnology executive board
  • Co-chair of the European Federation of Biotechnology Bioengineering & Bioprocessing section
  • Organiser of Applied Synthetic Biology in Europe conference series
  • Editorial board member for Biotechnology Letters
  • Refereeing for BMC Microbiology, FEMS Microbiology Letters, DNA Sequence, Powder Technology and the MRC and National Science Foundation
  • Peer review for FEBS Letters, Biotechnology Letters, BMC Microbiology, BMC Research Notes, FEMS Microbiology Letters, Powder Technology and DNA Sequence.
  • Grant application review for BBSRC, MRC and the National Science Foundation


Recent publications


Fernández-Castané, A, Li, H, Joseph, S, Ebeler, M, Franzreb, M, Bracewell, D, Overton, T & Thomas, O 2021, 'Nanoparticle tracking analysis as a process analytical tool for characterising magnetosome preparations', Food and Bioproducts Processing, vol. 127, pp. 426-434. https://doi.org/10.1016/j.fbp.2021.03.013

Golub, S & Overton, T 2021, 'Pellicle formation by Escherichia coli K-12: role of adhesins and motility', Journal of Bioscience and Bioengineering, vol. 131, no. 4, pp. 381-389. https://doi.org/10.1016/j.jbiosc.2020.12.002

Hothersall, J, Godfrey, R, Fanitsios, C, Overton, T, Busby, S & Browning, D 2021, 'The PAR promoter expression system: modified lac promoters for controlled recombinant protein production in Escherichia coli', New Biotechnology, vol. 64, pp. 1-8. https://doi.org/10.1016/j.nbt.2021.05.001

Fernández-Castané, A, Li, H, Joseph, S, Ebeler, M, Franzreb, M, Bracewell, D, Overton, T & Thomas, O 2020, 'Nanoparticle Tracking Analysis: A powerful tool for characterizing magnetosome preparations', bioRkiv. https://doi.org/10.1101/2020.06.23.166587

Leech, J, Golub, S, Allan, W, Simmons, M & Overton, T 2020, 'Non-pathogenic Escherichia coli biofilms: effects of growth conditions and surface properties on structure and curli gene expression', Archives of Microbiology, vol. 202, no. 6, pp. 1517–1527. https://doi.org/10.1007/s00203-020-01864-5

Masoura, M, Passaretti, P, Overton, T, Lund, P & Gkatzionis, K 2020, 'Use of a model to understand the synergies underlying the antibacterial mechanism of H2O2-producing honeys', Scientific Reports, vol. 10, no. 1, 17692. https://doi.org/10.1038/s41598-020-74937-6

Fallatah, H, Elhaneid, M, Ali-Boucetta, H, Overton, T, El Kadri, H & Gkatzionis, K 2019, 'Antibacterial effect of graphene oxide (GO) nano-particles against Pseudomonas putida biofilm of variable age', Environmental Science and Pollution Research, vol. 26, no. 24, pp. 25057–25070. https://doi.org/10.1007/s11356-019-05688-9

Whittle, EE, Legood, SW, Alav, I, Dulyayangkul, P, Overton, TW & Blair, JMA 2019, 'Flow cytometric analysis of efflux by dye accumulation', Frontiers in Microbiology, vol. 10, 2319. https://doi.org/10.3389/fmicb.2019.02319

Anvarian, A, Smith, M & Overton, T 2019, 'Flow cytometry and growth-based analysis of the effects of fruit sanitation on the physiology of Escherichia coli in orange juice', Food Science and Nutrition, vol. 7, no. 3, pp. 1072-1083. https://doi.org/10.1002/fsn3.947

Omajali, J, Mikheenko, I, Overton, T, Merroun, ML & Macaskie, L 2019, 'Probing the viability of palladium-challenged bacterial cells using flow cytometry', Journal of Chemical Technology and Biotechnology, vol. 94, no. 1, pp. 295-301. https://doi.org/10.1002/jctb.5775

Kasli, I, Thomas, O & Overton, T 2019, 'Use of a Design of Experiments approach to optimise production of a recombinant antibody fragment in the periplasm of Escherichia coli: selection of signal peptide and optimal growth conditions', AMB Express, vol. 9, 5. https://doi.org/10.1186/s13568-018-0727-8

Kubota, A, Kalnins, R & Overton, T 2018, 'A biorefinery approach for fractionation of Miscanthus lignocellulose using subcritical water extraction and a modified organosolv process.', Biomass and Bioenergy, vol. 111, pp. 52-59. https://doi.org/10.1016/j.biombioe.2018.01.019

Selas Castineiras, T, Williams, S, Hitchcock, A, Cole, J, Smith, D & Overton, T 2018, 'Development of a generic β-lactamase screening system for improved signal peptides for periplasmic targeting of recombinant proteins in Escherichia coli', Scientific Reports, vol. 8, 6986. https://doi.org/10.1038/s41598-018-25192-3

Fernández-Castané, A, Li, H, Thomas, O & Overton, T 2018, 'Development of a simple intensified fermentation strategy for growth of Magnetospirillum gryphiswaldense MSR-1: physiological responses to changing environmental conditions', New Biotechnology, vol. 46, pp. 22-30. https://doi.org/10.1016/j.nbt.2018.05.1201


Kelly, C, Overton, T & Jenkins, M 2019, Synthesis of biodegradable polyhydroxyalkanoates from soil bacteria. in BB Mishra & SK Nayak (eds), Frontiers in Soil and Environmental Microbiology. 1 edn, CRC Press, Boca Raton.

View all publications in research portal


Industrial microbiology, bioprocessing and biochemical engineering; recombinant protein production, biofilms and their uses; flow cytometry and FACS.