This program focuses primarily on the roles that microorganisms play in shaping the geochemical and isotopic characteristics of natural environments. Much work has been conducted on the geochemistry and geomicrobiology of hot springs, particularly in Kamchatka and Nevada, to better understand how life may have first originated on Earth. Be sure to click on the links to Kamchatka (especially the Exploratorium) and Nevada (see below) to get a flavor for the type of field projects we conduct.

• Jimenez-Lopez C., Romanek C.S. and Bazylinski D.A. 2010 Magnetite as a Prokaryotic Biomarker. Journal of Geophysical Research Biogeoscience, 115, G00G03

• Lee* Y-G, Romanek C.S. and Wiegel J. 2009 Desulfosporosinus youngiae sp. nov., a spore-forming sulfate-reducing bacterium isolated from constructed wetland sediment. International Journal of Systematic and Evolutionary Microbiology, 59, 2743-2746.

• Wagner I.D., Ahmed S., Zhao W., Zhang C.L., Romanek C.S., Rohde M. and Wiegel J. 2009 Caldanaerovirga acetigena gen. nov., sp. nov., an anaerobic xylanolytic bacterium isolated from Trego Hot Spring, Nevada, USA. International Journal of Systematic and Evolutionary Microbiology 59, 2685-2691.

• Lee* Y-G, Romanek C.S. and Wiegel J.  Desulfosporosinus youngiae sp. nov., a spore-forming sulfate-reducing bacterium isolated from constructed wetland sediment. International Journal of Systematic and Evolutionary Microbiology 59, 2743-2746.

• Zhang C.L., Ye Q., Huang Z., Li W.J., Chen J., Song Z., Zhao* W., Bagwell C, Inskeep W., Ross C., Gao L., Wiegel J.,Romanek C.S., Shock E.L. and Hedlund B.  2008  Global occurrence of Archaeal amoA genes in terrestrial hot springs.Applied and Environmental Microbiology 74, 6417-6426
• Pearson A., Pi Y., Zhao* W., Li W., Li Y., Inskeep W., Bonch-Osmolavskaya E., Romanek C.S., Li S. and Zhang C.L.  2008 Factors controlling the distribution of archaeal tetraethers in terrestrial hot springs. Applied and Environmental Microbiology74, 3523-3532.
• Wagner I.D., Zhao* W., Zhang C.L., Romanek C.S., Rohde M. and Wiegel J.  2008  Thermoanaerobacter uzonensis sp. nov., an anaerobic, thermophilic bacterium isolated from a hot spring within the Uzon Caldera, Kamchatka, Far East RussiaInternational Journal of Systematic and Evolutionary Microbiology 58, 2565-2573.
• Zhao* W., Zhang C.L., Romanek C.S. and Wiegel J.  2008 Description ofCaldalkalibacillus uzonensis sp. nov. and emended description of the genus Caldalkalibacillus.International Journal of Systematic and Evolutionary Microbiology 58, 1106-1108.
• Zhang C.L., Huang Z., Li Y.L., Romanek C.S., Mills G.L., Wiegel J., Culp R., Noakes J. and White D.C.  2007  Lipid biomarkers, carbon isotopes, and phylogenetic characterization of bacteria in Nevada and California hot springs. Geomicrobiol. J. 24, 519-534.
• Lee* Y.-J., Romanek C.S. and Wiegel J.,  2007  Clostridium aciditolerans sp. nov., an anaerobic spore-forming acid-tolerant bacterium from constructed wetland sediment. International Journal of Systematic and Evolutionary Microbiology, 57, 311-315
• Zhao W., Weber C., King G.M., Romanek C.S., Zhang C.L., Mills G., Sokolova T. and Wiegel J. 2006. Thermalkaliphus uzonensis gen. nov. sp. nov, a new aerobic thermophilic carbon-monoxide-tolerant bacterium isolated from a hot spring in Uzon Caldera, Kamchatka. Extremophiles 10, 337-345.
• Lee Y-J, Romanek C.S. Mills G.L. and Wiegel J. 2006.Gracilibacter thermotoleran gen. nov., sp. nov., a novel anaerobic thermotolerant bacterium from a constructed wetland receiving acid sulfate water. International J. Systematic and Evolutionary Microbiology 56, 2089-2093.
• Lee Y-J, Wagner I., Brice M.E., Kevbrin V.V., Mills G.L.,Romanek C.S., and Wiegel J. 2005. Thermosediminibacter oceani gen. nov., sp. nov. and Thermosediminibacter litoriperuensis sp. nov., new anaerobic thermophilic bacteria isolated from Peru Margin. Extremophiles 9, 375-383.
• Zhao W., Romanek C.S., Mills G., Wiegel J. and Zhang C.L.2005. Geochemistry and Microbiology of Hot Springs in Kamchatka, Russia. Geological Journal of China Universities11, 217-223
• Pearson A., Huang Z., Ingalls A.E., Romanek C.S., Wiegel J., Freeman K.H., Smittenberg R.H. and Zhang C.L. 2004. Non-marine crenarchaeol in Nevada hot springs. Appl. Environ. Microbiol. 70, 5229-5237.
• Kevbrin V.V., Romanek C.S. and Wiegel J. 2004.Alkalithermophiles: A double challenge from extreme environments. Section VI: Extremophiles and Biodiversity, Vol. 6 "Origins: Genesis, Evolution and the Biodiversity of Life". In:Cellular Origins, Life in Extreme Habitats and Astrobiology(COLE) (Ed. J. Seckbach), Kluwer Academic Publishers, Dordrecht, NL., 395-412.
• Zhang C.L., Fouke B., Bonheyo G., Peacock A., White D., Huang Y. and Romanek C. 2004 Lipid biomarkers and carbon isotopes of modern travertine deposits (Yellowstone National Park, USA): Implications for biogeochemical dynamics in hot-spring systems, Geochim. Cosmochim. Acta 68, 3157-3169.
• Clemett S.J., Thomas-Keptra K.L., Shimmin J., Morphew M., McIntosh J.R., Bazylinski D.A., Kirschvink J.L., Wentworth S.J., McKay D.S., Vali H., Gibson E.K. Jr and Romanek C.S. 2002. Crystal morphology of MV-1 magnetite Amer. Mineral.87, 1727-1730.
• Romanek C.S., Zhang C.L., Li Y., Horita J., Vali H., Cole D.H. and Phelps T.J. 2003. Carbon and hydrogen isotope fractionations associated with dissimilatory Fe(III)-reducing bacteria. Chem. Geol. 195, 5-16.
• Lyons T.W., Zhang C. and Romanek C.S. 2003. Isotopic Records of Microbially Mediated Processes. Chem Geol. 195, 1-4.
• Zhang, C., Vali, H., Romanek, C.S., Phelps, T.J. and Liu, S.V.1998. Formation of single-domain magnetite by a thermophilic bacterium. Amer. Mineralogist 83, 140-1418.
• Thomas-Keptra K., McKay D.S., Wentworth S.J., Stevens T.O., Taunton A.E., Allen C.C., Coleman A., Gibson E.K. Jr and Romanek C.S. 1998. Bacterial mineralization patterns in Columbia River basaltic environments: Implications for possible life in martian meteorite ALH84001. Geology 26, 1031-1034.