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Departments & Programs


Paula V. Welander

Title:Assistant Professor
Primary Affiliation:
Office Location:Green Earth Sciences Building, room 201
Research Lab:Welander Lab Website
Alternative Website:Paula Welander


I am a microbiologist with interests in understanding the biosynthesis and physiological function of “molecular fossils” or biomarkers in extant bacteria. Biomarker signatures in ancient rocks have been used to reconstruct important events in the Earth’s past, such as the first appearance of major groups of organisms, the catastrophic loss of biodiversity and the evolution of cyanobacteria and oxygenic photosynthesis. Despite the significant implications biomarker studies have on our interpretation of microbial evolution and of the Earth’s ancient environment, our understanding of the phylogenetic distribution and physiological function of most of these molecules in modern bacteria is quite limited. My research utilizes a combination of bioinformatics, microbial genetics, physiology, and biochemistry to address three general questions that can be applied to any biomarker: 1) what is its phylogenetic distribution in modern bacteria? 2) what are its physiological roles in modern bacteria? 3) what is the evolutionary history of its biosynthetic pathway?


My teaching will focus on two of my main interests: 1) microbial physiology and metabolism and 2) how molecular biosignatures are used to study microbial systems in both modern and ancient environments.

Professional Activities

NASA Exobiology and Evolutionary Biology Review Panel (August 2012); NASA Astrobiology Postdoctoral Fellow (2012- 2013); NSF Minority Postdoctoral Research Fellow (2008-2011); Invited presenter, Anaerobic Phototrophic Ecosystems Field Workshop (October 2010); Invited presenter, Organic Geochemistry Gordon Research Conference (August 2010); Invited presenter, 110th General Meeting of the American Society for Microbiology (May 2010); Member, American Society for Microbiology, American Geophysical Union


    Ph.D. in Microbiology, University of Illinois at Urbana-Champaign, Urbana, IL 2007
    M.S. in Microbiology, University of Illinois at Urbana-Champaign, Urbana, IL  2003
    B.A. in Kinesiology, Occidental College, Los Angeles, CA 1998

Professional Experience

    06/2013 - present | Assistant Professor (by courtesy), Department of Biology, Stanford University

    12/2012 – present | Assistant Professor, Department of Environmental Earth System Science, Stanford University

    01/2012 – 12/2012 | NASA Astrobiology Postdoctoral Fellow, Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology

    07/2011 – 01/2012 | Research Scientist, Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology

    7/2008 – 6/2011 | National Science Foundation Minority Postdoctoral Fellow, Departments of Biology and Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology

    07/2002 – 07/2005 | National Science Foundation Graduate Research Fellow, Department of Microbiology, University of Illinois at Urbana-Champaign

    08/2001 – 07/2002; 07/2005 - 08/2007 | Graduate College Fellow, Department of Microbiology, University of Illinois at Urbana-Champaign

    06/1999 – 07/2001 | Research Associate I, Department of Virology, Beckman Research Institute, City of Hope

    05/1998 – 06/1999 | Research Assistant I, Division of Biology, California Institute of Technology

Honors & Awards

    Gabilan Faculty Fellow, Stanford University 2013
    NASA Astrobiology Postdoctoral Fellowship, NASA Postdoctoral Program 2012
    OGD 2010 Best Paper Award, Geochemical Society 2011
    NSF Minority Postdoctoral Research Fellowship, National Science Foundation 2008
    Mame Shiao Debbie Award, University of Illinois at Urbana-Champaign 2006
    NSF Graduate Research Fellowship, National Science Foundation 2002
    Graduate College Fellowship, University of Illinois at Urbana-Champaign 2001
    NIH MCB Training Grant Fellowship, University of Illinois at Urbana-Champaign, Declined 2001
    Outstanding Teaching Assistant, University of Illinois at Urbana-Champaign Fall 2005 & Fall 2006
    Gordon Conference Minority Student Travel Grant 2003
    Howard Hughes Medical Institute Undergraduate Research Grant 1998
    Undergraduate Research Academic Support Program Grant, Occidental College 1997
    Richter Fellow 1997
    Cal Grant Recipient 1995 – 1998


    Ricci JN, Coleman ML, Welander PV, Sessions AL, Summons RE, Spear JR, Newman DK (2013) Diverse capacity for 2-methylhopanoid production correlates with a specific ecological niche. ISME J. 2013 Oct 24. doi: 10.1038/ismej.2013.191.


    Edgecomb VP, Bernhard JM, Beaudoin D, Pruss S, Welander PV, Shubotz F, Mehay S, Gillespie AL, and Summons RE (2013) Molecular indicators of microbial diversity in oolitic sands of Highborn Cay, Bahamas. Geobiology. 11:234-251.


    Sessions AL, , Zhang L, Welander PV, Doughty DM, Summons RE and Newman DK (2013) Identification and quantification of polyfunctionalized hopanoids by high temperature gas chromatography-mass spectrometry. Org. Geochem. 56: 120-130.


    Welander PV and Summons RE (2012) Discovery, taxonomic distribution, and phenotypic characterization of a gene required for 3-methylhopanoid production. Proc. Natl. Acad. Sci. 109: 12905-12910.


    Welander PV, Doughty DM, Wu CH, Mehay S, Summons RE and Newman DK (2012) Identification and characterization of Rhodopseudomonas palustris hopanoid biosynthesis mutants.  Geobiology. 10: 163-177.


    Garcia Costas AM, Tsukatani Y, Rijpstra WI, Schouten S, Welander PV, Summons RE and Bryant DA (2012) Identification of the bacteriochlorophylls, carotenoids, quinones, lipids, and hopanoids of Candidatus Chloracidobacterium thermophilum. J. Bacteriol. 194: 1158-68.


    Welander P, Cantin E, Lundberg P (2011) Using Taguchi-based statistics to produce robust PCR results. Bioprocessing. 10:22-26.


     Welander PV, Coleman MC, Sessions AL, Summons RE and Newman DK (2010) Identification of a methylase required for 2-methylhopanoid production and implications for the interpretation of sedimentary hopanes.  Proc. Natl. Acad. Sci. 107: 8537-8542.


    Sessions AL, Doughty DM, Welander PV, Summons RE and Newman DK (2009) The continuing puzzle of the great oxidation event.Curr. Biol. 19: R567-R574.


    Welander PV, Hunter RC, Zhang L, Sessions AL, Summons RE and Newman DK (2009) Hopanoids play a role in membrane integrity and pH homeostasis in Rhodopseudomonas palustris TIE-1. J. Bacteriol. 191: 6145-6156.


    Welander PV and Metcalf WW (2008) Mutagenesis of the C1 oxidation pathway in Methanosarcina barkeri: new insights into the Mtr/Mer bypass pathway. J. Bacteriol. 190: 1928-1936.


    Lundberg P, Welander PV, Edwards CK 3rd, van Rooijen N and Cantin E.  (2007) Tumor necrosis factor (TNF) protects resistant C57BL/6 mice against herpes simplex virus-induced encephalitis independently of signaling via TNF receptor 1 or 2.  J. Virol. 81: 1451-1460.


    Welander PV and Metcalf WW.  (2005) Loss of the mtr operon in Methanosarcina blocks growth on methanol, but not methanogenesis, and reveals an unknown methanogenic pathway. Proc. Natl. Acad. Sci. 102: 10664-10669.


    Lundberg P, Welander P, Openshaw H, Nalbandian C, Edwards C, Moldawer L and Cantin E. (2003) A locus on mouse chromosome 6 that determines resistance to herpes simplex virus also influences reactivation, while an unlinked locus augments resistance of female mice. J. Virol. 77: 11661-11673.


    Lundberg P, Welander P, Han X and Cantin E. (2003) Herpes simplex virus type 1 DNA is immunostimulatory in vitro and in vivo. J. Virol. 77: 11158-11169. 

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