My research interests involve understanding interactions between the microbial biosphere and the Earth’s geosphere and hydrosphere, particularly those influencing the form and fate of heavy metals in the environment. This work is multi-disciplinary, and has involved application of knowledge and techniques across mineralogy, electron microscopy, ion microscopy, aqueous geochemistry, x-ray and infrared spectroscopy, metagenomics and bioinformatics. My research group combines tools from the disciplines of geochemistry and microbiology to pursue questions along the interface of these fields (as most of the interesting geochemistry happening at or near the Earth’s surface involves microbiology). I have specialised and published extensively on the topics of microbial sulfur cycling and its impacts on metals from mining, microbial transformations of mercury, biomineralisation and bioremediation.
I moved my research program to Glasgow to take up a Readership at the University of Glasgow in July 2019, from an Associate Professorship at the School of Earth Sciences, The University of Melbourne (2008-2019). Prior to my appointment at Melbourne University, I held a U.S. National Research Council Fellowship at the U.S. Geological Survey (2006-2008). Before working at the USGS, I was a doctoral student in the Department of Earth and Planetary Sciences at the University of California-Berkeley.
Active research projects:
Exploring the mercury "chemiscape" of Scotland – Scotland has been receiving atmospherically deposited mercury for centuries, and today a significant amount of airborne mercury travelling over the UK derives from both local and continental fossil fuel combustion. This project seeks to establish the baseline distribution and speciation for mercury across Scotland, focusing on deposition to lake sediments, in order to predict the mobility and susceptibility to methylation of mercury under predicted climate change scenarios. Methylmercury is a neurotoxin that bioaccumulates through terrestrial and marine food webs, and should be of interest to the Scottish fisheries industry, as well as industries that utilise organic carbon (e.g., peat) that may contain some level of bioavailable mercury.
Developing catchment-scale lead remediation strategies for legacy tailings deposits in Scottish lead mining districts – Several lead mining districts across central Scotland have left a legacy of lead mining contamination to surface sediments and streams that remains to be addressed. These contaminant sources range from point-source to catchment scale, and the source-pathway-receptor model for potential lead ecotoxicity remains to be described in detail sufficient for developing useful remediation strategies. This project would characterise the speciation of lead in sediments, soils and waterways from source to sink along two key catchments southeast of Glasgow, with an aim to develop data-driven recommendations and strategies for long-term remediation.
Remediating the impacts of gold mining on groundwater – A long standing project in my lab, brought over from Australia, where gold mining forms a major sector of the Australian economy, involves using native consortia of autotrophic bacteria to biodegrade thiocyanate, a toxic waste product from gold ore processing. Although we have made much progress in learning how to optimise both the types of microorganisms involved in this process, and the conditions for optimal thiocyanate biodegradation efficiency, much work remains to be done still. This project would comparatively study different lab, field, batch and flow-through thiocyanate bioreactor systems, employing both geochemistry and bioinformatics, to unravel what key similarities and/or differences in microbial consortium composition and function might be exploited to optimise bioremediation efficiency.
Investigating the response of the deep subsurface microbial biosphere to anthropogenic perturbation – My group has investigated the response of deep subsurface microorganisms to anthropogenic perturbation such as injection of many tonnes of supercritical carbon dioxide in CO2 geosequestration experiments. In the UK, with its current interest in exploiting shallow geothermal energy, there is potential to widen this research area to include assessment of how groundwater microbes might affect well/borehole conditions and operations in the context of hydrothermal energy extraction.
Peer-reviewed publications ( *indicates directly supervised student or postdoc; note: I am last author on many of these papers because that is the convention in geomicrobiology for the supervising researcher):
Gionfriddo*, C.M., M.J. Stott, J. Power, J. Ogorek, D.P. Krabbenhoft, R. Wick, K.E. Holt, L.-X. Chen, B. Thomas, J.F. Banfield, and J.W. Moreau (2020, in press) Genome-resolved metagenomics and detailed geochemical speciation analyses yield new insights into microbial mercury cycling in geothermal springs, Applied and Environmental Microbiology.
Watts*, M.P., L.P. Spurr*, K.-A. Lê Cao, R. Wick, J.F. Banfield and J.W. Moreau (2019) Genome-resolved metagenomics of an autotrophic microbial thiocyanate-degrading bioreactor consortium. Water Research, 158, 106-117.
Cumberland*, S.A., B. Etschmann, J. Brugger, G. Douglas, K. Evans, L. Fisher, P. Kappen and J.W. Moreau (2018). Characterization of uranium redox state in organic-rich Eocene sediments. Chemosphere, 194, 602-613.
Watts*, M.P., H.M. Gan, L.Y. Peng, K.-A. Lê Cao and J.W. Moreau (2017). In situ stimulation of thiocyanate biodegradation through phosphate amendment in gold mine tailings water. Environmental Science & Technology, 51, pp. 13353-13362.
Gionfriddo*, C.M., M. Tate, R.R. Wick, M.B. Schultz, A. Zemla, M.P. Thelen, R. Schofield, D.P. Krabbenhoft, K.E. Holt and J.W. Moreau (2016) Microbial mercury methylation in Antarctic sea ice. Nature Microbiology, 1, article no. 16127, doi:10.1038/NMICROBIOL.2016.127.