The Pace Lab

University of Colorado-Boulder

"Go Team, Go"




Main Menu






Our Favorite Links

Microbiology Supergroup

Guerrero Negro Pictures


Hypersaline Evaporation Pond


Mat Slice



Environmental Microbiology

Current Projects:

Indoor Environments~ This project, funded by the Sloan Foundation, examines the microbial communities in human environments incuding hospitals, homes, public buildings, and water systems. Postdocs Laura Baumgartner and Piret Koll, graduate student Kim Ross, and technicians Steven Mihaylo and Kristen Peterson work on this project.

CAFOs~Concentrated animal feeding operations bring together large numbers of people and animals in an enclosed environment. This project, funded by NIOSH, examines the microbial constituents of air in CAFOs to determine a) what microbes are present and b) whether we can detect specific microorganisms of concern. Postdocs Piret Koll works on this project in collaboration with members of Dr. Mark Hernadez's laboratory in Environmental Engineering.

Guerrero Negro~ The Guerrero Negro hypersaline microbial mat of Baja California, Mexico has been a research site for the Pace Lab for years. The Bacterial, Archaeal, and Eukaryotic microbial diversity are the subjects of several studies previously conducted by Dr. John Spear, Dr. Ruth Ley, and undergraduates Alicia Berger and Leah Feazel, as well as ongoing investigation by Drs. Charles Robertson and Kirk Harris.

Yellowstone Microbial Mats~ This study is interested in dicovering what organisms form the multicolored microbial mats surrounding Yellowstone's hot springs. This study has been conducted by Kim Ross and Leah Feazel with the help of undergraduates Nikki Held, Mallory Chan, and graduate rotation students.


Past Projects and Publications

Rodriguez, M., J.J. Walker, N.R. Pace and M. Hernandez. (2010) Molecular source tracking of bioaerosols in the quarantined Katrina flood zone.  Aerosol Science Technol.  44:236-245.

Pace, N.R. (2009) Mapping the tree of life: progress and prospects. Microbiol. Mol. Biol. Rev. 73:564-576.

Baumgartner LK, Dupraz C, Buckley DH, Spear JR, Pace NR, and Visscher PT. (2009) Microbial species richness and metabolic activities in hypersaline microbial mats: Insight into biosignature formation through lithification. Astrobiology 9:861-874.

Feazel LM, Baumgartner LK, Peterson KL, Frank DN, Harris JK, and Pace NR. (2009) Opportunistic pathogens enriched in showerhead biofilms. PNAS 106: 16393-16399.

Baumgartner, LK, Spear, JR, Buckley, DH, Pace, NR, Reid, RP, Dupraz, C, and Visscher, PT (2009) Microbial diversity in modern marine stromatolites, Highborne Cay, Bahamas. Environ Microbiol. Published online July 6.

Robertson, CE, Spear, JR, Harris, JK, and Pace, NR (2009) Diversity and stratification of Archaea in a hypersaline microbial mat.
Appl Environ Microbiol 75:(7) 1801-1810.

Kunin, V, Raes, J, Harris, JK, Spear, JR, Walker, JJ, Ivanova, N, von Mering, C, Bebout, BM, Pace, NR, Bork, P, and Hugenholtz, P (2008) Millimeter-scale genetic gradients and community-level molecular convergence in a hypersaline microbial mat. Mol Syst Biol 4:198.

Sahl, JW, Pace, NR, and Spear, JR. (2008) Comparative molecular analysis of endoevaporitic microbial communities. Appl Environ Microbiol 74(20):6444-6.

Feazel LM, Spear JR, Berger AB, Harris JK, Frank DN, Ley RE, Pace NR. (2008) Eucaryotic diversity in a hypersaline microbial mat. Appl Environ Microbiol. 74(1):329-32.

Ley RE, Harris JK, Wilcox J, Spear JR, Miller SR, Bebout BM, Maresca JA, Bryant DA, Sogin ML, Pace NR. (2006) Unexpected diversity and complexity of the Guerrero Negro hypersaline microbial mat. Appl Environ Microbiol. 72(5):3685-95.

Salmassi TM, Walker JJ, Newman DK, Leadbetter JR, Pace NR, Hering JG. (2006) Community and cultivation analysis of arsenite oxidizing biofilms at Hot Creek. Environ Microbiol;8(1):50-9.

Robertson CE, Harris JK, Spear JR, Pace NR. (2005) Phylogenetic diversity and ecology of environmental Archaea. Curr Opin Microbiol. 8(6):638-42. Review.

Papineau D, Walker JJ, Mojzsis SJ, Pace NR. (2005) Composition and structure of microbial communities from stromatolites of Hamelin Pool in Shark Bay, Western Australia. Appl Environ Microbiol. 71(8):4822-32.

Jakosky BM, Anbar AD, Des Marais D, Morrison D, Pace NR. (2005) Don't dismiss astrobiology. Science. 308(5721):495-7.

Walker JJ, Spear JR, Pace NR. (2005) Geobiology of a microbial endolithic community in the Yellowstone geothermal environment.Nature. 434(7036):1011-4.

Spear JR, Walker JJ, McCollom TM, Pace NR.(2005) Hydrogen and bioenergetics in the Yellowstone geothermal ecosystem. Proc Natl Acad Sci U S A. 102(7):2555-60.

Kelley ST, Theisen U, Angenent LT, St Amand A, Pace NR. (2004) Molecular analysis of shower curtain biofilm microbes. Appl Environ Microbiol. 70(7):4187-92.

Harris JK, Kelley ST, Pace NR. (2004) New perspective on uncultured bacterial phylogenetic division OP11. Appl Environ Microbiol. 70(2):845-9.

The Big Tree


A significant part of what we do in environmental search is expansion of the three domain tree of life. Since many microbes are difficult to culture, many have only recently been discovered through sequencing of conserved genes such as that for the small subunit of the ribosomal RNA.


Yellowstone Pictures


Octopus Spring Mat



Obsidian Pool



Cinder Pool