Knowledge for a sustainable world

PhD, MPhil, BSc

Dr John Milledge is a member of Algal Biotechnology Research Group at the University of Greenwich which he joined in 2013. He returned to research 13 years ago after a long spell in company management and has worked on several projects, both macro and microalgal, over the past 13 years for Pure Energy Fuels and the Universities of Southampton & Greenwich.

Dr Milledge’s current primary interest is in potential exploitation of the genus Sargassum for biofuel and other products. Sargassum is a broad genus or family of brown seaweed consisting of around 300 species Sargassum muticum is an invasive species to the coasts of the British Isles. Holopelagic or floating Sargassum (S. natans and S. fluitans) in the open ocean, is a tremendous ecological and climate resource. However, enormous beach inundations, or golden tides, in the last ten years are causing economic and environmental challenges.

Commercial exploration could encourage Sargassum harvesting and control. Macroalgae may be a potential source of fuel.  However, practical yields of biogas from the anaerobic digestion of macroalgae are substantially below the theoretical maximum. Sargassum has a naturally high content of antioxidants, carotenoids, sulphated compounds, halogenated compounds and phenols, making this genus also a potential source of a range of pharmaceutically relevant materials.  Can we change these golden tides into a golden opportunity?

John’s other interests include anaerobic digestion, algal biotechnology and the energy balance of algal biofuels.

The focus of John’s research at National College of Food Technology in the late 1970s and early 1980s with Unilever was on the hygienic design of food plant and the cleanability of stainless steel in particular.  He still keeps a ‘weather-eye’ on the topic, although, it is not the primary focus of his work.

It has been said that a curious mind cannot be satisfied. We all come into the world with curiosity. John is still curious and fascinated with science, and his interest in his areas of research will continue long after his retirement.

Dr Milledge teaches on the following:

  • BIOT-1013-Natural Product Biotechnology
  • CIVI-1131- Water Engineering
  • CHEE-1003- Reactor Engineering
  • GEEN-1148- Water and Wastewater Engineering 
  • John has also made contributions to:
  • BIOC-1017- MSc Biomedical Science Projects
  • BIOC-1025- Bioanalytical Techniques
  • COMP-1730- Information Technologies for Environmental Engineering 
  • ENVI-1164- Energy, Life and Resources
  • FOOD-1036- Marketing, Innovation and Management
  • GEEN-1147- Development Engineering for Water and Sanitation 
  • NUTR-1028-Human Nutrition 2
  • RESE-1132- Research and Professional Skills in Life Science

Dr Milledge is currently working on a Darwin Plus Project- Sustainable Solutions for Sargassum Inundations in Turks & Caicos. His past experience of the food industry with Unilever Research, University of Reading and others is also of value in his involvement with an INTERREG V 2 Seas project, Valgorize, that looks towards the valorisation of seaweed and microalgae as food on the European market.

John’s past project involvement at Greenwich includes:

  • MacroBiocrude funded by EPSRC
  • D-Factory - The Microalgae Biorefinery funded by EU FP7
  • Glycerol Fuel Supply Chain - Interreg IVA Channel Project Ecotec21
  • Novel application of brown seaweed as an antibacterial coating for interdental drug delivery funded by the High Value Chemicals from Plants Network (HVfCP) and Mirage Health Group.
  • Road Map for the use of the Seaweed Sargassum muticum in High Value Bioactive Compound Discovery funded by HVfCP and IOTA Phamaceuticals

Dr Milledge is currently supervising the following PhD students and projects:

2nd supervisor
Enhancing Biogas Production from Anaerobic Digestion of Seaweed - Supattra Maneein
Effect of iodine on methanogenesis - Md Mahmud Al Farid

  • 2020, Milledge, J.J.; Maneein, S.; Arribas López, E.; Bartlett, D. Sargassum Inundations in Turks and Caicos: Methane Potential and Proximate, Ultimate, Lipid, Amino Acid, Metal and Metalloid Analyses. Energies, 13, 1523.
  • 2020, Milledge, J.J.; Maneein, S. Chapter 6 - Storage of seaweed for biofuel production: Ensilage. In Sustainable Seaweed Technologies, Torres, M.D., Kraan, S., Dominguez, H., Eds. Elsevier: 155-167.
  • 2020, Nielsen, B.V.; Maneein, S.; Al Farid, M.M.; Milledge, J.J. The Effects of Halogenated Compounds on the Anaerobic Digestion of Macroalgae. Fermentation, 6,
  • 2019, Milledge, J.J.; Nielsen, B.V.; Maneein, S.; Harvey, P.J. A Brief Review of Anaerobic Digestion of Algae for Bioenergy. Energies, 12, 1166.
  • 2019, Milledge, J.J.; Thompson, E.P.; Sauvêtre, A.; Schroeder, P.; Harvey, P.J. Novel developments in biological technologies for wastewater processing. In Sustainable Water and Wastewater Processing, Galanakis, C.M., Agrafioti, E., Eds. Elsevier.
  • 2018, Milledge, J.J.; Harvey, P. Anaerobic digestion and gasification of seaweed. In Grand Challenges in Marine Biotechnology, Rampelotto, P.H.; Trincone, A., Eds. Springer Cham.
  • 2018, Milledge, J.J.; Nielsen, B.V.; Harvey, P.J. The inhibition of anaerobic digestion by model phenolic compounds representative of those from Sargassum muticum. J. Appl. Phycol.
  • 2018, Milledge, J.; Nielsen, B.; Sadek, M.; Harvey, P. Effect of Freshwater Washing Pretreatment on Sargassum muticum as a Feedstock for Biogas Production. Energies, 11, 1771.
  • 2018, Maneein, S.; Milledge, J.J.; Nielsen, B.V.; Harvey, P.J. A Review of Seaweed Pre-Treatment Methods for Enhanced Biofuel Production by Anaerobic Digestion or Fermentation. Fermentation, 4, 100.
  • 2017, Milledge, J.; Heaven, S. Energy balance of biogas production from microalgae: Effect of harvesting method, multiple raceways, scale of plant and combined heat and power generation. J of Marine Sci and Eng, 5, 9.
  • 2016, Milledge, J.J.; Harvey, P. Golden tides: Problem or golden opportunity? The valorisation of Sargassum from beach inundations. Journal of Marine Science and Engineering, 4, 60.
  • 2016, Milledge, J.J.; Harvey, P.J. Potential process ‘hurdles’ in the use of macroalgae as feedstock for biofuel production in the British Isles. Journal of Chemical Technology & Biotechnology, 91, 2221-2234
  • 2016, Milledge JJ, Harvey PJ Ensilage and anaerobic digestion of Sargassum muticum J Appl Phycol, 28, 3021-3030
  • 2016, Redden, H.; Milledge, J.J.; Greenwell, H.C.; Dyer, P.W.; Harvey, P.J. Changes in higher heating value and ash content of seaweed during ensiling. J Appl Phycol, 1-10.
  • 2015, Milledge JJ, Nielsen B, and Bailey D High-value products from macroalgae: The potential uses of the invasive brown seaweed, Sargassum muticum. Reviews in Environmental Science and Bio/Technology, 1-22.
  • 2015, Milledge JJ and Heaven S Energy Balance of Biogas Production from Microalgae: Development of an Energy and Mass Balance Model. Current Biotechnology 4, (4) 554-567.
  • 2015, Milledge JJ, Staple A, and Harvey P Slow Pyrolysis as a Method for the Destruction of Japanese Wireweed, Sargassum muticum. Environment and Natural Resources Research, 5, (1)
  • 2015, Xu Y, Milledge JJ, Abubakar A, Swamy R, Bailey D, and Harvey PJ Effects of centrifugal stress on cell disruption and glycerol leakage from Dunaliella salina. Microalgae Biotechnology, 1, 20-27
  • 2014, Milledge JJ, Smith B, Dyer P, and Harvey P Macroalgae-Derived Biofuel: A Review of Methods of Energy Extraction from Seaweed Biomass. Energies, 7, 7194-222.

Lead for the Nutrition and Food Group

  • Guest Editor Algal Biotechnology and Biofuels Special Edition of Energies.
  • Guest Editor Algal Biofuels Special Edition of Journal of Marine Science and Engineering
  • Former Editor in Chief of Environment and Natural Resources Research (ENRR) 2011-2017
  • Former Member Mid-Kent College Advisor Committee
  • Former Member Engineering Panel North West Kent College
  • John has also been an external PhD examiner for both the University of Sheffield and University of Karachi.


Community Activities

  • Member Kent Society of Rugby Union Football Referees                                                               
  • Past President Gravesend & Meopham Rotary Club
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