Alexander S. Bradley
Campus Box 1169
1 Brookings Dr
Saint Louis MO 63130-4899
Organic & Isotope Geochemistry, Geobiology, Microbiology
Alex Bradley studies the coevolution of life and the Earth. He is interested in using techniques from both geochemistry and biology to better understand the history of life and how biogeochemical cycles have changed through Earth history.
One part of this work pertains to the study of organic geochemistry. Organic geochemistry involves the characterization of the molecular structures and stable isotopic compositions of biological products detected in the environment. The information obtained from these molecules can be used in a wide range of applications, from understanding the cycling of carbon through ecosystems, to characterizing petroleum, to examining environmental contaminants, to reconstructing paleoclimate.
Another part of this work involves conducting laboratory experiments to gain a better understanding of the information contained in geochemical biomarkers. Many aspects of physiology and environment can influence the suite of products produced by different organisms, as well as the stable isotopic compositions of the products. Through careful laboratory experimentation, we can arrive at a better understanding of how to interpret the signals we observe in the geochemical record.
Bradley, A.B., Leavitt, W.D., & Johnston, D.T. 2011. Revisiting the dissimilatory sulfate reduction pathway. Geobiology 9 :446-457.
Bradley, A.S. Pearson, A., Saenz, J.P., & Marx, C.J. 2010. Adenosylhopane: the first intermediate in hopanoid side chain biosynthesis. Organic Geochemistry 41: 1075-1081.
Bradley, A.S. Hayes, J.M. & Summons, R.E. 2009. Extraordinary 13C enrichment of dither lipids at the Lost City Hydrothermal Field indicates a carbon-limited ecosystem. Geochimica et Cosmochimica Acta 73: 102-118.
Bradley, A.S., Fredricks, H., Hinrichs, K-U., & Summons, R.E. 2009. Structural diversity of diether lipids in carbonate chimneys at the Lost City Hydrothermal Field. Organic Geochemistry 40: 1169-1178.