Daniel Boone Caverns Manganese Coating (from Carmichael et al., 2013)The presence of manganese oxide minerals on the surface of the Earth often indicates the presence of manganese oxidizing microbes.  These black mineral deposits are found coating the surfaces of rocks in places such as deserts, streams, springs, and caves. Interdisciplinary geomicrobiology research at Appalachian State University by Dr. Suzanna Bräuer (Biology), Dr. Sarah Carmichael (Geology), and Dr. Cara Santelli (University of Minnesota) attempts to understand the complex relationships between microbes and rocks, and the role of microbes in the cycling of manganese both in the present and throughout deep time.

Our work explores manganese cycling in caves in the southern Appalachians, manganese biomineralization in wetlands and acid mine drainage sites, as well as manganese ore deposits throughout the region.

Our research has been funded by the National Science Foundation, NC Space Grant, Appalachian State University, Cave Research Foundation, Geological Society of America, and a variety of other organizations.

Current and past research projects include:

  • Characterization of ferromanganese deposits in southern Appalachian caves, wetlands, and surface waters
  • Manganese biomineralization by fungi in southern Appalachian caves
  • Microbial ecology in ferromanganese deposits in cave systems, wetlands, and surface waters
  • Genetics of both Mn-oxidizing bacteria and fungi
  • Valence states of Mn(II/III/IV) in biomineralizing fungal cells
  • Biological origins for Mn oxide ore deposits in the southern Appalachians
  • Mn-oxidizing bacterial communities in high-elevation wetlands
  • The role of anthropogenic impact in Mn cycling in caves

Awards, News and Press

March 2017 - Sarah Carmichael inducted as a Fellow into the Explorers Club

September 2016 - Sarah Carmichael (PI) and co-PIs across the Departments of Geology and Biology receive NSF-MRI grant (NSF-MRI-EAR #1625137, $561,842) for purchase of a new scanning electron microscope for the Dewel Microscopy Facility

August 2016 - Sarah Carmichael elected Councilor of the Mineralogical Society of America (2017-2019 term)

April 2016 - Group alumna Mary Jane Carmichael receives the 2016-2017 AAUW American Dissertation Fellowship

April 2016 - Suzanna Bräuer receives 100 Scholars Award

December 2015 - the Geomicrobiology group receives RIEEE-CONCERT funding to start a pilot project on using biominerals and brewery waste to treat acid mine drainage

April 2015 - Graduate student Mara Cloutier wins awards from Cave Research Foundation and Geological Society of America

November 2014 - Suzanna Bräuer receives Fulbright-Saastamoien Foundation Award 

October 2014 - Sarah Carmichael receives William C. Strickland Outstanding Junior Faculty Award

December 2011 - Carmichael-Bräuer geomicrobiology research group's work on microbial biominerals spotlighted in the Appalachian News 

Winter 2011 - Cara Santelli's work in on cave geomicrobiology showcased in the Smithsonian's NMNH Department of Mineral Sciences Newsletter 


Suzanna Bräuer

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