Prof Andy Mitchell

Prof Andy Mitchell

Professor in Microbial Geochemistry

Department of Geography and Earth Sciences

Contact Details


Andy's interests are in the importance of microbes in regulating many common chemical reactions at the Earth's surface and in the deep subsurface, specifically through the interaction with mineral surfaces. He is particularly interested in how such processes allow microorganisms to survive in cold and icy environments and potentially on other planets. Andy also undertakes applied research into manipulating these biogeochemical processes for environmental engineering purposes, including metal and radionuclide pacification and geologic carbon capture and storage. Before coming to Aberystwyth, he was at Montana State University where he was an Assistant Research Professor in the Faculty of Chemical and Biological Engineering. Prior to this, Andy was a EU Marie Curie Fellow at the NanoGeoScience Centre, University of Copenhagen, a Postdoctoral Fellow in the Department of Microbiology, Montana State University, and a Postdoctoral Fellow in the Department of Geology, University of Toronto. Andy has travelled and worked all over the world, and is particularly drawn to mountainous areas and mountain sports.

Additional Information

Prospective postgraduate students

Very interested to hear from any students with interests in microbe-mineral interactions, mineral formation and stability, metal and radionuclide pacification, carbon capture and storage, glacial biogeochemistry and microbiology. Possible sources of funding available.

Current PhD Students:

  • Andre Soares
  • Ian Stevens
  • Melanie Hay
  • Sarah Easter
  • Keegan Burrows
  • Joe Dean
  • Guglielmo Persiani

Current Postdoctoral fellows:

  • Dr. Sara Rassner (NRN-LCEE)
  • Dr. Pallavee Srivastara (Royal Society)
  • Dr. Karina Sand (EU Horizon 2020 COFUND)


Lab and field based Microbial Geochemistry:

  • Microbe-metal-sediment interaction, transport and deposition
    • Biogeochemistry in glacierised and snow covered environments
    • Environmental engineering - Bioremediation in surface and groundwater; Subsurface geologic carbon sequestration, enhanced oil recovery

Recent Grants and funding:

  • NERC Standard Grant (2021 – 2024) Cryo365: Are There Perennial and Light-Independent Microbial Processes on Supraglacial Ecosystems? Co-Principal investigator (£624,675).
  • NERC Subglacial Lake CECs in Antarctica (2021-2025) Subglacial Lake Exploration: Diversity, Geochemistry, Ecology (SLEDGE) - Lake CECs Microbiology. Co-Principal investigator (£599,000).
  • Aberystwyth University Research Fund (2019-2020) Quantitative analysis of biologically synthesized selenium for application in Photovoltaics. Principal investigator (£9000).
  • HEFCW research capital investment grant. Chemical and Biological Interface Imaging facility. TEM-EDX and SEM-EDX facility development. Principal investigator (£405,000).
  • NERC Standard Grant (2019 – 2022) MicroMelt: How will glacial meltwater microbes come in from the cold in this “Peak Melt” century? Co-Principal investigator, Aberystwyth University (£723,000).
  • EDRF KESS PhD Studentship – 2020 – 2023 (PI and Host). The geomicrobiology and biogeochemistry of heat production and biofouling in mine water geothermal energy recovery. Partner. British Geological Survey (£52,400).
  • Royal Society Newton – SERB Postdoctoral Fellowship 2018 2020 (PI and Host). New insight into the microbial transformation of selenium for bio-remediation and bio-recovery – Dr. Pallavee Srivastara (£64,000).
  • Ser Cymru National Research Network for Low Carbon Energy and Environment PI and organizer. Ser Cymru Distinguished Visiting Experts Scheme. Subsurface Biotechnology Workshop. Aberystwyth University. June 5th - 7th 2018. £9000.
  • EDRF KESS PhD Studentship – 2018 – 2021 (PI and Host). Metal recovery and CO2 sequestration with steel production waste materials. Partner. TATA Steel (£52,400).
  • EU Marie Curie COFUND postdoctoral fellowship 2017-2020 (PI and Host). KAT-TRAP: Kinetic And Thermodynamic controls on calcium carbonate formation during geologic carbon TRAPping project - Dr. Karina Sand (£198,000).
  • EU Innovative Training Networks (ITN). 2016-2020. ‘MicroArctic’. Microorganisms in Warming Arctic Environments. No. 675546. £3.8M. Work Package Leader and Co-Investigator.
  • Sêr Cymru National Research Network award for Low Carbon, Energy and the Environment 2015-2019. 'Geo-Carb-Cymru' The potential of low carbon subsurface energy in Wales. Manager / Principal investigator. Partners Cardiff University, British Geological Survey, The 'Big Pit' National Coal Museum of Wales. (£771,000).
  • HEFCW research capital investment 2013-16. Ex2EL Extreme Experimental Environments Laboratory. Manager / Principal investigator. (£350,000).

Prospective postgraduate students

Very interested to hear from any students with interests in microbe-mineral interactions, mineral formation and stability, metal and radionuclide pacification, carbon capture and storage, glacial biogeochemistry and microbiology. Possible sources of funding available.


2016 - present. Co-Director - Interdisciplinary Centre for Environmental Microbiology

2019 - present. Director of Postgraduate Studies, Department of Geography and Earth Sciences. 

2017-2019. Director of Research (Science). Department of Geography and Earth Sciences. 

2013 - present. Manager - Extreme Experimental Environments Laboratory (Ex2El)

2017 - present. Associate Editor  - Frontiers in Geochemistry

2018 - present. UK Geo microbiology Society Committee Member

Research Groups


Chen, M, Masum, SA, Sadasivam, S, Thomas, HR & Mitchell, AC 2023, 'Modeling Gas Adsorption–Desorption Hysteresis in Energetically Heterogeneous Coal and Shale', Energy and Fuels, vol. 37, no. 3, pp. 2149-2163. 10.1021/acs.energyfuels.2c03441
Almolliyeh, M, Tripathy, S, Sadasivam, S, Masum, S, Rassner, SE, Mitchell, A & Thomas, HR 2023, 'Subcritical CO2 adsorption on geomaterials of coal-bearing strata in the context of geological carbon sequestration', International Journal of Coal Geology, vol. 277, 104340. 10.1016/j.coal.2023.104340
Turetta, C, Barbaro, E, Skidmore, ML, Gambaro, A, Michaud, AB, Mitchell, AC, Vick-Majors, TJ, Priscu, JC & Barbante, C 2023, 'Trace element, rare earth element and trace carbon compounds in Subglacial Lake Whillans, West Antarctica', Science of the Total Environment, vol. 892, 164480. 10.1016/j.scitotenv.2023.164480
Stevens, IT, Irvine-Fynn, TDL, Edwards, A, Mitchell, AC, Cook, JM, Porter, PR, Holt, TO, Huss, M, Fettweis, X, Moorman, BJ, Sattler, B & Hodson, AJ 2022, 'Spatially consistent microbial biomass and future cellular carbon release from melting Northern Hemisphere glacier surfaces', Communications Earth & Environment, vol. 3, no. 1, 275. 10.1038/s43247-022-00609-0
Irvine-Fynn, T, Edwards, A, Stevens, IT, Mitchell, A, Bunting, P, Box, J, Cameron, K, Cook, J, Naegeli, K, Rassner, SME, Ryan, J, Stibal, M, Williamson, C & Hubbard, A 2021, 'Storage and export of microbial biomass across the western Greenland Ice Sheet', Nature Communications, vol. 12, no. 1, 3960. 10.1038/s41467-021-24040-9
More publications on the Research Portal