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John’s research is translational and cross-disciplinary in nature which encompasses microbiology, biochemistry, microbial ecology, metagenomics-metatranscriptomics, engineering, and chemistry.  Much of his research effort is devoted to understanding how microbial communities can be managed to remove and recycle value added products from waste, make renewable energy sustainable, and improve human health.  Specifically this work focuses on: 

1. The biogeochemistry of microbial phosphorus and organophosphorus cycling in the marine, freshwater, terrestrial, agri-food and engineered (anaerobic digestor and activated sludge) environments

2. Development of biological and chemical approaches for the removal and/or recovery of high-value compounds from waste eg. phosphorus, ammonia, volatile fatty acids, formaldehyde, herbicides etc)

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John welcomes applications from prospective PhD students on relevant subjects (see above, and publications section of fuller academic profile for relevant topics). John has to date supervised 15 successful PhDs and currently supervises 12 doctoral students.

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Professor John McGrath

School of Biological Sciences 

 Prof John McGrath Staff Profile


John McGrath is Professor of Environmental Microbiology within the School of Biological Sciences and IGFS and a Director of the Irish Nutrient Sustainability Platform. 


  • Member of International Advisory Panel for the Enterprise Ireland funded Dairy Processing Technology Centre (2018 – Present)
  • UK Microbiology Society Policy Committee Member (2016 -Present)
  • Editor of mSystems (Journal of the American Society for Microbiology: 2016 - Present)
  • UK Representative on United States National Science Foundation Sustainable Phosphorus Research Coordination Network
  • Member of European Sustainable Phosphorus Platform (ESPP) (2015 – Present
  • External Examiner (Undergraduate) University College Dublin – Microbiology (2016 – Present)
  • Chair Microbiology Society (Irish Division): 2009 - 2011
  • External reviewer for NUI-Galway’s Institutional Review of Research Performance (2012)
  • External assessor for lectureship positions at NUI-Galway (2010 and 2014)




Faculty of Medicine, Health and Life Sciences

School of Biological Sciences

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