
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
2003
Journal Article
A critical stage in the formation of acid mine drainage: Colonization of pyrite by Acidithiobacillus ferrooxidans under pH-neutral conditions
Mielke, Randall E., Pace, Danielle L., Porter, Tim and Southam, Gordon (2003). A critical stage in the formation of acid mine drainage: Colonization of pyrite by Acidithiobacillus ferrooxidans under pH-neutral conditions. Geobiology, 1 (1), 81-90. doi: 10.1046/j.1472-4669.2003.00005.x
2002
Journal Article
Could bacteria have formed the Precambrian banded iron formations?
Konhauser, KO, Hamade, T, Raiswell, R, Morris, RC, Ferris, FG, Southam, G and Canfield, DE (2002). Could bacteria have formed the Precambrian banded iron formations?. Geology, 30 (12), 1079-1082. doi: 10.1130/0091-7613(2002)0302.0.CO;2
2001
Journal Article
Structural characterization of the hydrocarbon degrading bacteria-oil interface: implications for bioremediation
Southam, G, Whitney, M and Knickerbocker, C (2001). Structural characterization of the hydrocarbon degrading bacteria-oil interface: implications for bioremediation. International Biodeterioration & Biodegradation, 47 (4), 197-201. doi: 10.1016/S0964-8305(01)00051-8
2001
Journal Article
Pyrite discs in coal: Evidence for fossilized bacterial colonies
Southam, G, Donald, R, Rostad, A and Brock, C (2001). Pyrite discs in coal: Evidence for fossilized bacterial colonies. Geology, 29 (1), 47-50. doi: 10.1130/0091-7613(2001)0292.0.CO;2
2000
Journal Article
The role of ''blebbing'' in overcoming the hydrophobic barrier during biooxidation of elemental sulfur by Thiobacillus thiooxidans
Knickerbocker, C, Nordstrom, DK and Southam, G (2000). The role of ''blebbing'' in overcoming the hydrophobic barrier during biooxidation of elemental sulfur by Thiobacillus thiooxidans. Chemical Geology, 169 (3-4), 425-433. doi: 10.1016/S0009-2541(00)00221-7
2000
Journal Article
Preface: Geomicrobiology
Konhauser, KO and Southam, G (2000). Preface: Geomicrobiology. Chemical Geology, 169 (3-4), 263-263. doi: 10.1016/S0009-2541(00)00206-0
2000
Journal Article
Immobilization of free ionic gold and L-asparagine complexed ionic gold by Sporosarcina ureae: The importance of organo-gold complexes in gold mobility
Southam, G, Fyfe, WS and Beveridge, TJ (2000). Immobilization of free ionic gold and L-asparagine complexed ionic gold by Sporosarcina ureae: The importance of organo-gold complexes in gold mobility. Minerals & Metallurgical Processing, 17 (2), 129-132.
1999
Journal Article
A structural comparison of bacterial microfossils vs. 'nanobacteria' and nanofossils
Southam, G and Donald, R (1999). A structural comparison of bacterial microfossils vs. 'nanobacteria' and nanofossils. Earth-Science Reviews, 48 (4), 251-264. doi: 10.1016/S0012-8252(99)00057-4
1999
Journal Article
Low temperature anaerobic bacterial diagenesis of ferrous monosulfide to pyrite
Donald, R and Southam, G (1999). Low temperature anaerobic bacterial diagenesis of ferrous monosulfide to pyrite. Geochimica Et Cosmochimica Acta, 63 (13-14), 2019-2023. doi: 10.1016/S0016-7037(99)00140-4
1999
Journal Article
The impact of sediment fecal coliform reservoirs on seasonal water quality in Oak Creek, Arizona
Crabill, C, Donald, R, Snelling, J, Foust, R and Southam, G (1999). The impact of sediment fecal coliform reservoirs on seasonal water quality in Oak Creek, Arizona. Water Research, 33 (9), 2163-2171. doi: 10.1016/S0043-1354(98)00437-0
1999
Journal Article
Relative contributions of abiotic and biological factors in Fe(II) oxidation in mine drainage
Kirby, CS, Thomas, HM, Southam, G and Donald, R (1999). Relative contributions of abiotic and biological factors in Fe(II) oxidation in mine drainage. Applied Geochemistry, 14 (4), 511-530. doi: 10.1016/S0883-2927(98)00071-7
1999
Journal Article
Efficiency of a subsurface constructed wetland system using native southwestern US plants
Maschinski, J, Southam, G, Hines, J and Strohmeyer, S (1999). Efficiency of a subsurface constructed wetland system using native southwestern US plants. Journal of Environmental Quality, 28 (1), 225-231. doi: 10.2134/jeq1999.00472425002800010027x
1998
Journal Article
Quantification of sulfur and phosphorus within secondary gold rims on Yukon placer gold
Southam, G (1998). Quantification of sulfur and phosphorus within secondary gold rims on Yukon placer gold. Geology, 26 (4), 339-342. doi: 10.1130/0091-7613(1998)0262.3.CO;2
1998
Conference Publication
The corrosion of carbon steel in rock microcosms containing native Yucca Mountain Microorganisms
Castro, P. R., Amy, P. S., Crossen, H. V., Jones, D. A., Southam, G., Donald, R. and Ringelberg, D. B. (1998). The corrosion of carbon steel in rock microcosms containing native Yucca Mountain Microorganisms. Corrosion 1998, San Diego, CA, March 22, 1998-March 27, 1998. National Assoc. of Corrosion Engineers International.
1998
Journal Article
Geomicrobiology of sulfide mineral oxidation
Nordstrom, D. Kirk and Southam, Gordon (1998). Geomicrobiology of sulfide mineral oxidation. Reviews in Mineralogy, 35, 381-390. doi: 10.2138/rmg.1998.35.11
1997
Journal Article
Geomicrobiology of sulfide mineral oxidation
Nordstrom, DK and Southam, G (1997). Geomicrobiology of sulfide mineral oxidation. Geomicrobiology: Interactions Between Microbes and Minerals, 35, 361-390.
1996
Journal Article
The occurrence of sulfur and phosphorus within bacterially derived crystalline and pseudocrystalline octahedral gold formed in vitro
Southam, G and Beveridge, TJ (1996). The occurrence of sulfur and phosphorus within bacterially derived crystalline and pseudocrystalline octahedral gold formed in vitro. Geochimica Et Cosmochimica Acta, 60 (22), 4369-4376. doi: 10.1016/S0016-7037(96)00235-9
1995
Conference Publication
THE OAK CREEK NATIONAL MONITORING PROJECT
RICO, JM, SOUTHAM, G, HARRISON, T and FOUST, RD (1995). THE OAK CREEK NATIONAL MONITORING PROJECT. WASHINGTON: AMER CHEMICAL SOC.
1995
Journal Article
Biogeochemical Phenomena Induced by Bacteria Within Sulfidic Mine Tailings
Fortin, D, Davis, B, Southam, G and Beveridge, TJ (1995). Biogeochemical Phenomena Induced by Bacteria Within Sulfidic Mine Tailings. Journal of Industrial Microbiology, 14 (2), 178-185. doi: 10.1007/BF01569901
1994
Journal Article
The In-Vitro Formation of Placer Gold by Bacteria
Southam, G and Beveridge, TJ (1994). The In-Vitro Formation of Placer Gold by Bacteria. Geochimica Et Cosmochimica Acta, 58 (20), 4527-4530. doi: 10.1016/0016-7037(94)90355-7
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
Alternative uses of mine influenced water
Associate Advisor
Other advisors: Dr Mandana Shaygan, Professor Mansour Edraki
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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
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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