Overview
Background
Professor Southam is a Professor in Geomicrobiology. He is an interdisciplinary researcher who crosses the traditional boundaries between biological and geological sciences to examine bacterial transformations of materials composing the earth’s crust, and the impact these transformations have had over geologic time. Field sites have ranged from Yellostone National Park, to Axel Heiberg Island in the Canadian high arctic, to the ultradeep gold mines in the Republic of Southam Africa (up to 4 km below land surface, to the Amazon Basin. Following his appointment as a Canada Research Chair in Geomicrobiology and Director of Environment and Sustainability at Western University, Canada, Dr. Southam has moved to the University of Queensland where he is leading projects on:
Mineral carbonation, using acid generating bacteria to enhance weathering of ultramafic mine waste, promoting mineral carbonation (CO2 sequestration);
Bioremediation of iron mine sites, by enhancing the biogeochemical cycling of iron to promote the formation of ferruginous duricrusts (canga), and
Bioleaching, focussing on low-grade copper in arid through tropical ecosystems (Australia and Brazil);
Gold exploration, examining the fundamental roles that bacteria play in catalysing the formation of placer gold.
Availability
- Professor Gordon Southam is:
- Available for supervision
Qualifications
- Bachelor (Honours) of Science (Advanced), University of Guelph
- Doctor of Philosophy, University of Guelph
Research interests
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Life in Extreme Environments / Bacterial Fossilisation
The growth of bacteria in extreme environments combined with their metal-reactive cell envelopes often results in their fossilization in these environments. The preservation of cellular and molecular biomarkers in ancients Earth systems can teach us about the evolution of life on Earth and their influence on lithosphere-hydrosphere-atmosphere system processes. The diversity of life’s extremes is also intriguing with the respect to the possibility of life occurring elsewhere in the solar system, e.g., Mars. Current research is improving our understanding of the fundamental processes responsible for fossilisation in contemporary and ancient Earth environments, e.g., the biooxidation of iron and subsequent per-mineralization in arid, acid environments.
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Bioleaching
Present day mining operations have reached geological scales. Entire mountains are being mined, crushed, sorted, transported, smelted, and consumed by an ever-increasing human population. In parallel, new landscapes are being created with the waste products, often low-grade or lesser-quality ores. Extracting resources from these low-grade ores presents major challenges that we propose to address by determining the critical steps controlling the biooxidation of copper sulphides, in particular, chalcopyrite. The solubilisation, speciation, fractionation and precipitation of many metals and metal ions are directly and indirectly influenced by microbial activity (Southam & Saunders, 2005). The significance of microbial catalysis is highlighted in Enders et al. (2006) where we demonstrated the role of bacteria in the supergene weathering of Fe and Cu at Morenci, AZ, the largest copper mine in North America, producing 1,000 tonnes of Cu/day through bacterial leaching. The biogeochemical oxidation of iron and sulphur in pyrite enhances the dissolution of copper, which can lead to supergene enrichment over geologic time scales (Enders et al., 2006) and can be exploited for the recovery of Cu through bioleaching.
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Canga
Supergene enriched iron-ore deposits are typically protected by a goethite-cemented ferruginous duricrust layer referred to as canga. The formation of canga horizons has been linked to the biogeochemical cycling of iron. Incredibly, no work on the biogeochemistry of canga has been done. These supergene Fe-ore systems are actively forming in the tropics by weathering of banded iron formations. Canga forms extensive deposits blanketing ancient erosion surfaces, is tough, moderately hard, well consolidated, permeable and very resistant to erosion and chemical weathering, protecting the relatively soft enriched iron ore below. This protective canga horizon is therefore, essential to supergene iron ore enrichment and formation of high-grade iron ore. Canga hosts unique, endemic open herbaceous-shrubs, dominated by hemicryptophytes that are in dramatic contrast to the surrounding vegetation, especially in the Carajás and Quadrilátero Ferrífero regions of Brazil where tropical rainforests surrounds these ‘islands’ of canga. Effective restoration of mined iron sites to re-establish these unique ecosystems requires the re-precipitation of canga, a process never previously attempted. Studying the biology of these systems, i.e., the biogeochemical cycling of iron and the identification of novel biotechnologically important organisms is essential for the success of this project.
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Gold
Gold is a relatively inert metal, yet it is often found as concentrated placer deposits. These deposits are unusual because the gold nuggets recovered from them can be larger than the gold found in the source rock. Using gold-thiosulfate, the gold complex important in base metal sulphide systems, we demonstrated that thiosulfate-oxidising and thiosulfate-reducing bacteria can produce octahedral gold, similar to the interaction between bacteria and gold(III)-chloride complexes. Synchrotron results have begun to elucidate the mechanism of octahedral gold formation, demonstrating that organosulphur-Au(I) compounds are the intermediate complex produced during the reaction between bacteria and gold(III) chloride. Both complexes are important to the biogeochemical cycling of gold in natural systems. Recent evidence of biofilms on gold grains demonstrates that biogeochemical processing of gold is occurring in nature and is therefore, fundamentally important to mineral exploration programs.
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Mineral Carbonation
Ultramafic and mafic mine tailings are a potentially valuable feedstock for carbon mineralization that should be used to offset carbon emissions generated by mining. Passive carbon mineralization is occurring at the abandoned Clinton Creek asbestos mine, and the active Diavik diamond and Mount Keith nickel mines. Microbially mediated processes have the potential to accelerate carbon mineralization to create economically viable, large-scale carbon dioxide fixation technologies that can operate at ambient temperature and atmospheric pressure. Bioleaching of magnesium silicates (serpentine, olivine); increasing the supply of CO2 via heterotrophic oxidation of waste organics; and biologically induced carbonate precipitation, as well as enhancing passive carbonation through tailings management practices and use of CO2 point sources. With the aim of developing carbon-neutral mines, tailings storage facilities could be geoengineered as habitats for microbial communities that accelerate carbon mineralization.
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Methanogenesis
The methanogenesis project aims to determine how microorganisms degrade coal and to demonstrate the feasibility of producing biogenic methane from waste coal in an abandoned mine. Through this project, we will conduct a microbial survey of at least two Bowen Basin coal mines to identify the organisms that thrive where coal is the sole source of organic carbon. The future methane production of these mines will be determined in a laboratory trial using two different chemical regimes, one possessing a gradient from aerobic to anaerobic conditions and in the other solely anaerobic. Finally, coal will be separated into physical and chemical fractions to determine why coal degradation by anaerobic organisms is limited by the hydrolysis step during methane production.
Works
Search Professor Gordon Southam’s works on UQ eSpace
2019
Journal Article
Changes in microbial community structure and increased metal bioavailability in a metal-contaminated soil and in the rhizosphere of corn (Zea mays)
Mahrous, Nahed N., Columbus, Melanie P., Southam, Gordon and Macfie, Sheila M. (2019). Changes in microbial community structure and increased metal bioavailability in a metal-contaminated soil and in the rhizosphere of corn (Zea mays). Rhizosphere, 11 100169, 100169. doi: 10.1016/j.rhisph.2019.100169
2019
Journal Article
Deficiencies of secondary Fe (oxy)hydroxides associated with phyllosilicates and organic carbon limit the formation of water-stable aggregates in Fe-ore tailings
Wu, Songlin, Nguyen, Tuan A. H., Liu, Yunjia, Southam, Gordon, Wang, Shuncai, Chan, Ting-Shan, Lu, Ying-Rui and Huang, Longbin (2019). Deficiencies of secondary Fe (oxy)hydroxides associated with phyllosilicates and organic carbon limit the formation of water-stable aggregates in Fe-ore tailings. Chemical Geology, 523, 73-87. doi: 10.1016/j.chemgeo.2019.06.002
2019
Journal Article
Zinc and lead encapsulated in amorphous ferric cements within hardpans in situ formed from sulfidic Cu-Pb-Zn tailings
Liu, Yunjia, Wu, Songlin, Southam, Gordon, Nguyen, Tuan A. H., Kopittke, Peter M., Paterson, David J. and Huang, Longbin (2019). Zinc and lead encapsulated in amorphous ferric cements within hardpans in situ formed from sulfidic Cu-Pb-Zn tailings. Environmental Pollution, 252 (part B), 1106-1116. doi: 10.1016/j.envpol.2019.06.069
2019
Journal Article
Bacterial influence on storage and mobilisation of metals in iron-rich mine tailings from the Salobo mine, Brazil
Henne, A., Craw, D., Gagen, E. J. and Southam, G. (2019). Bacterial influence on storage and mobilisation of metals in iron-rich mine tailings from the Salobo mine, Brazil. Science of The Total Environment, 680, 91-104. doi: 10.1016/j.scitotenv.2019.04.448
2019
Conference Publication
The effects of a sulphur oxidising bacterial inoculum and elemental sulphur amendment on alkaline iron ore tailings pH stabilisation
Yi, Qing, Wu, Songlin, Huang, Longbin and Southam, Gordon (2019). The effects of a sulphur oxidising bacterial inoculum and elemental sulphur amendment on alkaline iron ore tailings pH stabilisation. Goldschmidt2019, Barcelona, Spain, 18-23 August 2019.
2019
Journal Article
Deciphering biosignatures in planetary contexts
Chan, Marjorie A., Hinman, Nancy W., Potter-McIntyre, Sally L., Schubert, Keith E., Gillams, Richard J., Awramik, Stanley M., Boston, Penelope J., Bower, Dina M., Des Marais, David J., Farmer, Jack D., Jia, Tony Z., King, Penelope L., Hazen, Robert M., Leveille, Richard J., Papineau, Dominic, Rempfert, Kaitlin R., Sanchez-Roman, Monica, Spear, John R., Southam, Gordon, Stern, Jennifer C. and Cleaves, Henderson James (2019). Deciphering biosignatures in planetary contexts. Astrobiology, 19 (9) ast.2018.1903, 1075-1102. doi: 10.1089/ast.2018.1903
2019
Journal Article
Phosphate treatment alleviated acute phytotoxicity of heavy metals in sulfidic Pb-Zn mine tailings
Saavedra-Mella, Felipe, Liu, Yunjia, Southam, Gordon and Huang, Longbin (2019). Phosphate treatment alleviated acute phytotoxicity of heavy metals in sulfidic Pb-Zn mine tailings. Environmental Pollution, 250, 676-685. doi: 10.1016/j.envpol.2019.04.100
2019
Conference Publication
Ni stress to sulphate reducing bacteria enhances Ni complexation: Opportunity for Ni-Co separation from wastewater
Liu, Yun, Wyman, Valentina, Serrano, Antonio, Southam, Gordon, Vaughan, James and Villa Gomez, Denys K. (2019). Ni stress to sulphate reducing bacteria enhances Ni complexation: Opportunity for Ni-Co separation from wastewater. IWA 16th World Conference on Anaerobic Digestion Conference AD16, Delft, The Netherlands, 23-27 June 2019.
2019
Journal Article
Organic matter preservation and incipient mineralization of microtubules in 120 Ma basaltic glass
Izawa, Matthew R. M., Dynes, James J., Banerjee, Neil R., Flemming, Roberta L., MacLean, Lachlan C. W., Hetherington, Callum J., Matveev, Sergei and Southam, Gordon (2019). Organic matter preservation and incipient mineralization of microtubules in 120 Ma basaltic glass. Frontiers in Earth Science, 7 149. doi: 10.3389/feart.2019.00149
2019
Journal Article
The biogeochemical reactivity of phosphate during bioleaching of bornite-chalcocite ore
Bostelmann, Heike and Southam, Gordon (2019). The biogeochemical reactivity of phosphate during bioleaching of bornite-chalcocite ore. Applied Geochemistry, 104, 193-201. doi: 10.1016/j.apgeochem.2019.03.003
2019
Journal Article
Biogeochemical processes in canga ecosystems: armoring of iron ore against erosion and importance in iron duricrust restoration in Brazil
Gagen, Emma J., Levett, Alan, Paz, Anat, Gastauer, Markus, Caldeira, Cecílio Frois, Valadares, Rafael Borges da Silva, Bitencourt, José Augusto Pires, Alves, Ronnie, Oliveira, Guilherme, Siqueira, Jose Oswaldo, Vasconcelos, Paulo M. and Southam, Gordon (2019). Biogeochemical processes in canga ecosystems: armoring of iron ore against erosion and importance in iron duricrust restoration in Brazil. Ore Geology Reviews, 107, 573-586. doi: 10.1016/j.oregeorev.2019.03.013
2019
Journal Article
Geochemical and mineralogical constraints in iron ore tailings limit soil formation for direct phytostabilization
Wu, Songlin, Liu, Yunjia, Southam, Gordon, Robertson, Lachlan, Chiu, Tsz Ho, Cross, Adam T., Dixon, Kingsley W., Stevens, Jason C., Zhong, Hongtao, Chan, Ting-Shan, Lu, Ying-Jui and Huang, Longbin (2019). Geochemical and mineralogical constraints in iron ore tailings limit soil formation for direct phytostabilization. Science of The Total Environment, 651 (Part 1), 192-202. doi: 10.1016/j.scitotenv.2018.09.171
2019
Journal Article
Performance of a sulfidogenic bioreactor inoculated with indigenous acidic communities for treating an extremely acidic mine water
González, Daniella, Liu, Yun, Villa Gomez, Denys, Southam, Gordon, Hedrich, Sabrina, Galleguillos, Pedro, Colipai, Camila and Nancucheo, Ivan (2019). Performance of a sulfidogenic bioreactor inoculated with indigenous acidic communities for treating an extremely acidic mine water. Minerals Engineering, 131, 370-375. doi: 10.1016/j.mineng.2018.11.011
2019
Conference Publication
Experimental acid and scCO2 reactions of Roseneath, Epsilon and Murteree gas shales: opening or closing of gas accessible pores and metal release to water
Pearce, J.K., Blach, T., Dawson, G., Melnichenko, Y., Southam, G., Golding, S.D., Bahadur, J. and Paterson, D. (2019). Experimental acid and scCO2 reactions of Roseneath, Epsilon and Murteree gas shales: opening or closing of gas accessible pores and metal release to water. AEGC 2019, Perth, WA, Australia, 2-5 September 2019. Taylor & Francis. doi: 10.1080/22020586.2019.12073164
2019
Book Chapter
Geomicrobiology of sulfide mineral oxidation
Nordstrom, D. Kirk and Southam, Gordon (2019). Geomicrobiology of sulfide mineral oxidation. Geomicrobiology: interactions between microbes and minerals. (pp. 361-390) edited by Jillian F. Banfield and Kenneth H. Nealson . Berlin, Germany: De Gruyter Mouton. doi: 10.1515/9781501509247
2019
Conference Publication
Accelerating bauxite residue remediation with microbial biotechnology
Santini, T. C., Warren, K., Raudsepp, M., Carter, N., Hamley, D., McCosker, C., Couperthwaite, S., Southam, G., Tyson, G. W. and Warren, L. A. (2019). Accelerating bauxite residue remediation with microbial biotechnology. Light Metals Symposium held at the TMS Annual Meeting and Exhibition, 2019, San Antonio, TX United States, 10-14 March 2019. Cham, Switzerland: Springer. doi: 10.1007/978-3-030-05864-7_10
2019
Journal Article
Carbon sequestration in biogenic magnesite and other magnesium carbonate minerals
McCutcheon, Jenine, Power, Ian M., Shuster, Jeremiah, Harrison, Anna L., Dipple, Gregory M. and Southam, Gordon (2019). Carbon sequestration in biogenic magnesite and other magnesium carbonate minerals. Environmental Science and Technology, 53 (6) acs.est.8b07055, 3225-3237. doi: 10.1021/acs.est.8b07055
2019
Book Chapter
Applications of transmission electron microscopy in geomicrobiology
Shuster, Jeremiah, Reith, Frank and Southam, Gordon (2019). Applications of transmission electron microscopy in geomicrobiology. Analytical geomicrobiology: a handbook of instrumental techniques. (pp. 166-186) edited by Kenney, Janice P. L, Veeramani, Harish and Alessi, Daniel S. Cambridge, United Kingdom: Cambridge University Press. doi: 10.1017/9781107707399.006
2019
Journal Article
Small but mighty: microorganisms offer inspiration for mine remediation and waste stabilisation
Levett, Alan, Gagen, Emma J. and Southam, Gordon (2019). Small but mighty: microorganisms offer inspiration for mine remediation and waste stabilisation. Microbiology Australia, 40 (4), 190-194. doi: 10.1071/MA19055
2019
Book Chapter
Applications of scanning electron microscopy in geomicrobiology
Shuster, Jeremiah, Southam, Gordon and Reith, Frank (2019). Applications of scanning electron microscopy in geomicrobiology. Analytical geomicrobiology: a handbook of instrumental techniques. (pp. 148-165) edited by Janice P. L. Kenney, Harish Veeramani and Daniel S. Alessi. Cambridge, United Kingdom: Cambridge University Press.
Funding
Current funding
Past funding
Supervision
Availability
- Professor Gordon Southam is:
- Available for supervision
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Supervision history
Current supervision
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Doctor Philosophy
Investigation of the interface between electrochemically-active microorganisms and metals
Principal Advisor
Other advisors: Dr Bernardino Virdis
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Doctor Philosophy
Investigation of the interface between electrochemically-active microorganisms and metals
Principal Advisor
Other advisors: Dr Bernardino Virdis
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Doctor Philosophy
Investigation of the interface between electrochemically-active microorganisms and metals
Principal Advisor
Other advisors: Dr Bernardino Virdis
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Doctor Philosophy
Investigation of the interface between electrochemically-active microorganisms and metals
Principal Advisor
Other advisors: Dr Bernardino Virdis
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Doctor Philosophy
Investigation of the interface between electrochemically-active microorganisms and metals
Principal Advisor
Other advisors: Dr Bernardino Virdis
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Doctor Philosophy
Acid Mine Drainage Passive Treatment Method Using Hyperaccumulator Plants for Post Mining Rehabilitation
Associate Advisor
Other advisors: Dr Denys Villa Gomez, Professor Peter Erskine
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Doctor Philosophy
Alternative uses of mine influenced water
Associate Advisor
Other advisors: Dr Mandana Shaygan, Professor Mansour Edraki
Completed supervision
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2024
Doctor Philosophy
Understanding the microbiology behind transformation of coal mine spoils to soils, in the Bowen Basin
Principal Advisor
Other advisors: Dr Paul Evans
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2024
Doctor Philosophy
Biochemical processes occuring in kimberlite: True lithotrophy
Principal Advisor
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2024
Doctor Philosophy
Harnessing microbial processes to accelerate the transformation of coal spoils to functional soils
Principal Advisor
Other advisors: Professor Peter Erskine, Dr Paul Evans
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2023
Doctor Philosophy
Biologically enhanced mineral carbonation of kimberlite as a strategy to create a carbon neutral mine
Principal Advisor
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2020
Doctor Philosophy
Development of ferruginous duricrusts (canga) in tropical iron ore systems
Principal Advisor
Other advisors: Professor Paulo Vasconcelos
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2020
Doctor Philosophy
The role of primary producers in surface evolution of iron-rich duricrust (canga)
Principal Advisor
Other advisors: Professor Peter Kopittke
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2019
Doctor Philosophy
Selective colonisation of metal sulphides and the effect of bioleaching
Principal Advisor
Other advisors: Professor Paulo Vasconcelos
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2017
Doctor Philosophy
Microbial carbonation in natural and engineered environments
Principal Advisor
Other advisors: Professor Gregory Webb
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2016
Doctor Philosophy
Coal mine microbial communities and biogenic methane cycling
Principal Advisor
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2022
Doctor Philosophy
Microbial sulfur oxidation driven mineral weathering in alkaline iron ore tailings
Associate Advisor
Other advisors: Dr Fang You, Professor Longbin Huang
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2022
Doctor Philosophy
Improving biogeochemical properties and pioneer plant growth in alkaline iron ore tailings undergoing soil formation
Associate Advisor
Other advisors: Dr Fang You, Professor Longbin Huang
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2022
Doctor Philosophy
Geochemical investigation of abandoned tungsten mining wastes for metal recovery and rehabilitation
Associate Advisor
Other advisors: Professor Mansour Edraki
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2020
Doctor Philosophy
Strategies for nickel and cobalt recovery from mine-impacted water using sulfate-reducing bacteria
Associate Advisor
Other advisors: Associate Professor James Vaughan, Dr Denys Villa Gomez
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2020
Doctor Philosophy
Characteristics of hardpans capping sulfidic Cu-Pb-Zn tailings and potential roles of mineral bio-weathering
Associate Advisor
Other advisors: Professor Longbin Huang
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2018
Doctor Philosophy
Characterization of South Australian microbialites with emphasis on the identification of geochemical signatures
Associate Advisor
Other advisors: Honorary Professor Robert Burne, Professor Gregory Webb
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2018
Doctor Philosophy
Phosphate-induced hydrogeochemical stabilisation of sulphidic lead-zinc tailings for rapid phytostabilisation
Associate Advisor
Other advisors: Professor Longbin Huang
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2017
Doctor Philosophy
Paleoenvironmental Evolution of Continental Landscapes Through Combined High-Resolution Geochronology and d18O Ion Microprobe Analysis of Goethite
Associate Advisor
Other advisors: Professor Paulo Vasconcelos
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