Jan P. Amend

Associate Professor
Ph.D., Geochemistry, University of California at Berkeley, 1995

• EPSc 323 : Biogeochemistry
• EPSc 330 : Geomicrobiology
• EPSc 444 : Environmental Geochemistry
• EPSc 448 : Microbial Geochemistry
• EPSc 480 : Special Topics in Microbiology-Chemistry-Earth Science

Microbial Geochemistry

Professor Amend’s research group combines geochemistry, microbiology, and molecular biology to study the chemical connections between microorganisms and their natural environment. The approach combines experimental, theoretical, analytical, and field components. Most of Professor Amend’s research efforts are aimed at the microbial geochemistry of hydrothermal systems. Since microbes thriving at very high temperatures (hyperthermophiles) were first isolated several decades ago, they have captured the interests of microbiologists, molecular biologists, and biochemists. Because the metabolisms of these novel organisms are intimately tied to the chemistry of their natural environments, geochemists have started to investigate the roles of thermophiles in marine and continental surface and subsurface environments. Professor Amend’s field areas include the hydrothermal systems of the Aeolian Islands, north of Sicily, Italy and those at Yellowstone National Park in the western United States, two of the most prolific sites of hyperthermophilic activity. Current projects in Professor Amend’s group include:

• Sampling by SCUBA the shallow marine vents near Vulcano and Panarea Islands in Sicily and characterizing the geochemical environment in which a wide variety of hyperthermophiles are known to thrive.
  
• Designing growth media based on geochemical data and thermodynamic calculations to isolate, characterize, and study novel organisms in the Aeolian Islands and Yellowstone.
  
• Carrying out growth experiments to investigate the overall metabolic energy requirements of several classes of hyperthermophiles, including methanogens, sulfur reducers, and microaerophiles.
  
• Studying the aqueous organic geochemistry of hot springs in Italy, Yellowstone, and Iceland to identify natural carbon sources for heterotrophic microorganisms.
  
• Calculating thermodynamic properties of aqueous biochemical compounds as functions of temperature and pressure using group additivity equations of state; these properties will permit, among others, a quantitative assessment of the energetics of intracellular metabolic reactions.

The Aeolian Islands. View of the Baia di Levante, Baia di Ponente, and Vulcanello. In the background are the islands of Lipari (left) and Panarea and Stromboli (right).	Elemental sulfur atop La Fossa, Vulcano. The islands of Lipari and Salina are in the background.
Jan Amend and Franco Italiano prepare for a dive to sample the hydrothermal vent fluids at Campo Sette and La Calcara near Panarea.	Hydrothermal fluids at temperatures up to 100°C emanate from the sea floor at ~20m below sealevel near Panarea.

Meyer-Dombard, D.R., Price, R.E., Pichler, T., and Amend, J.P., Prokaryotic populations in heated, arsenic-rich sediments of a shallow-sea hydrothermal system, Ambitle Island, Papua New Guinea. Applied and Environmental Microbiology (submitted).

Amend, J.P. and McCollom, T.M. (2009) Energetics of biomolecule synthesis on early Earth. ACS Book (in press).

Shock, E.L., Holland, M., Meyer-Dombard, Amend, J.P., Osburn, G.R., and Fischer, T.P. (2009) Quantifying inorganic sources of geochemical energy in hydrothermal ecosystems, Yellowstone National Park, USA. Geochimica et Cosmochimica Acta (in press).

Amend, J.P. (2009) A brief review of microbial geochemistry in the shallow-sea hydrothermal system of Vulcano Island (Italy). Wissenschaftliche Mitteilungen der Bergakademie Freiberg, 39, 61-67.

Rusch, A. and Amend, J.P. (2008) Functional characterization of the microbial community in geothermally heated marine sediments. Microbial Ecology, 55, 723-736.

Amend, J.P. (2007) Il Vulcano: from Hephaistos to Helgeson. Geochemical News, 133, October.

Rogers, K.L., Amend, J.P., and Gurrieri, S. (2007) Temporal changes in fluid chemistry and energy profiles in the Vulcano Island hydrothermal system. Astrobiology, 7, 905-932.

Hoehler, T.M., Amend, J.P., and Shock, E.L. (2007) A “Follow the Energy” approach for astrobiology. Astrobiology, 7, 819-823.

Price, R.E., Amend, J.P., and Pichler, T (2007) Enhanced geochemical gradients in a marine shallow-water hydrothermal system: Unusual arsenic speciation in horizontal and vertical pore water profiles. Applied Geochemistry, 22, 2595-2605.

Skoog, A., Vlahos, P., Rogers, K.L., and Amend, J.P. (2007) Concentration and distribution of dissolved neutral aldoses in a shallow hydrothermal vent system of Vulcano, Italy. Organic Geochemistry, 38, 1416-1430.

Pichler, T., Price, R.E., Amend, J.P., Meyer-Dombard, D.R., Hsia, N.P., Hallock, P., McCloskey, B.J., and Karlen, D. (2006) A Natural Laboratory to Study Arsenic Geobiocomplexity. EOS, 87, 6 June, 221, 225-226.

Rogers, K.L. and Amend, J.P. (2006) Energetics of heterotrophic metabolisms in the marine hydrothermal system of Vulcano Island, Italy. Geochimica et Cosmochimica Acta, 70, 6180-6200.

Kappler, A., Emerson, D., Edwards, K., Amend, J.P., Gralnick, J.A., Grathwohl, P., Hoehler, T., and Straub, K.L. (2005) Microbial activity in biogeochemical gradients – new aspects of research. Geobiology, 3, 229-233.

Shock, E.L., Holland, M., Meyer-Dombard, D.R., and Amend, J.P. (2005) Geochemical sources of energy for microbial metabolism in hydrothermal ecosystems: Obsidian Pool, Yellowstone National Park, USA. In: Geothermal Biology and Geochemistry of Yellowstone National Park (W.P. Inskeep and T.R. McDermott, eds.), pp. 95-112.

Rogers, K. L. and Amend, J. P. (2005) Archaeal diversity and geochemical energy yields in a geothermal well on Vulcano Island, Italy. Geobiology 3, 319-332.

Meyer-Dombard, D.R., Shock, E.L., and Amend, J.P. (2005), Thermophilic Communities in Three Geochemically Distinct Geothermal Ecosystems, Yellowstone National Park, USA. Geobiology 3, 211-227.

Rusch, A., Walpersdorf, E., deBeer, D., Gurrieri, S., and Amend, J.P. (2005), Microbial communities near the oxic/anoxic interface in the hydrothermal system of Vulcano Island, Italy. Chemical Geology 224, 169-182 (2005).

McCollom, T.M. and Amend, J.P. (2005), A thermodynamic assessment of energy requirements for biomass synthesis by chemolithoautotrophic microorganisms in oxic and anoxic environments. Geobiology 3, 135-144 (2005).

Amend, J.P. and Teske, A. (2005), Expanding frontiers in deep subsurface microbiology. Paleogeography, Paleoclimatology, Paleoecology, 219, 131-155.

Svensson, E., Skoog, A., and Amend, J.P. (2004), Concentration and distribution of dissolved amino acids in a shallow hydrothermal vent system, Vulcano Island (Italy). Organic Geochemistry, 35, 1001-1014.

Amend, J.P., Rogers, K.L., Meyer-Dombard, D.R. (2004), Microbially mediated sulfur-redox: energetics in marine hydrothermal vent systems. In: Sulfur Biogeochemistry-Past and Present, Geological Society of America Special Paper 379 (J.P. Amend et al., eds.), GSA Press, pp. 17-34.

Rusch, A. and Amend, J.P. (2004), Order-specific 16S rRNA targeted oligonucleotide probes for (hyper)thermophilic archaea and bacteria. Extremophiles, 8, 357-366.

Amend, J.P., Rogers, K.L., Shock, E.L., Inguaggiato, S., and Gurrieri, S. (2003), Energetics of chemolithoautotrophy in the hydrothermal system of Vulcano Island, southern Italy. Geobiology, 1, 37-58.

Amend, J.P., Meyer-Dombard, D.R., Sheth, S.N., Zolotova, N., and Amend, A.C. (2003), Palaeococcus helgesonii sp. nov., a facultatively anaerobic, hyperthermophilic archaeon from a geothermal well on Vulcano Island, Italy. Archives of Microbiology, 179, 394-401.

Tor, J.M., Amend, J.P., Lovley, D.R. (2003), Metabolism of organic compounds in anaerobic, hydrothermal sulfate-reducing sediments. Environmental Microbiology, 5, 583-591.

Amend, J.P. and Plyasunov, A.V. (2001), Carbohydrates in thermophile metabolism: Calculation of the standard molal thermodynamic properties of aqueous pentoses and hexoses at elevated temperatures and pressures. Geochimica et Cosmochimica Acta, 65, 3901-3917.

Amend, J.P. and Shock, E.L. (2001), Energetics of overall metabolic reactions of thermophilic and hyperthermophilic Archaea and Bacteria. FEMS Microbiology Reviews, 25, 175-243.

See also Department Publications

314-935-8651	amend@levee.wustl.edu
314-935-7361