Dr. Annette Summers Engel's
Abbreviated C.V.

Professional Experience

Research Interests

Publications

Current Research Funding

Participation in Professional Meetings and Conferences

Invited Presentations & Workshop Participation

Student Dissertation and Thesis Direction

EDUCATION    

Ph.D. (2004) University of Texas at Austin, Department of Geological Sciences. Advisor: PC Bennett pdf of dissertation
M.S. (1999) University of Cincinnati, Department of Biology. Advisor: BK Kinkle
M.S. (1997) University of Cincinnati, Department of Geology. Advisor: W Huff
B.A. (1995) Wittenberg University, Springfield, Ohio; Department of Geology. Undergrad Thesis Advisor: J Ritter

PROFESSIONAL EXPERIENCE

- Since August 2004. Assistant Professor of Geomicrobiology. Louisiana State University, joint tenure-track appointment in the Department of Geology & Geophysics (primary department) and Department of Biological Sciences (secondary department)

- August 1999- May 2004. Research and/or Graduate Teaching Assistantship. The University of Texas at Austin, Department of Geological Sciences. Research: 2000-2004 (NSF grants, the John Jackson Fellowship for Hydrology, University of Texas Endowed Presidential Fellowship). Teaching: Earth, Wind, & Fire (1999); Chemical Hydrogeology (2000-2004); Field Methods in Hydrogeology (2001; 2003)

- August 1997- May 1999. Graduate Teaching Assistant. University of Cincinnati, Ohio, Department of Biological Sciences. Teaching: Introductory Biology I, II, III (1997-1999); Ecology and Evolution (1998-1999); Scientific Writing in Biology (1998; 1999)

- August 1995- May 1996. Graduate Teaching Assistant. University of Cincinnati, Ohio, Department of Geology. Teaching: Introductory Geology I & II; Geology for Majors

- June - October 1995. Petroleum Geologist, Intern. Timan Pechura Companies (Exxon Subsidiary), Houston, TX. Worked in Cincinnati, Ohio, on pay and non-pay geometries.

RESEARCH INTERESTS

Geomicrobiology: microbial geochemistry; microbial ecology; microbial diversity; low-temperature aqueous geochemistry; stable isotope geochemistry; karst geochemistry and geomorphology; carbonate diagenesis

Link to Louisiana State University Geomicrobiology & Environmental Microbiology Studies (GEMS) Research Website

SELECTED PUBLICATIONS
⁺ Corresponding Author; ^CG Collaborator Graduate Student; ^LSUG LSU Grad Student;
^LSUU LSU Undergraduate; ^{LSU PD} LSU Collaborating Post-doc

For a full list, as well as pdfs or links to abstracts, go to GEMS Publications

- Birdwell, J.E.^{LSU PD+}, and Engel, A.S. (ACCEPTED) Characterization of dissolved organic matter in cave and spring waters using UV-Vis absorbance and fluorescence spectroscopies. Organic Geochemistry.

- Engel, A.S.,⁺ Meisinger, D.B.^CG , Porter, M.L.^{LSU PD}, Payn, R.A.^PD, Schmid, M., Stern, L.A., Schleifer, K.-H., Lee, N.M. (2009) Linking phylogenetic and functional diversity to nutrient spiraling in microbial mats from Lower Kane Cave (USA). The ISME Journal. Advanced Online. doi:10.1038/ismej.2009.91

- Engel, A.S., and Engel, S.A. (Editors) (2009) Select Field Guides to Cave and Karst Lands of the United States. Karst Waters Institute Special Publication 15, 184 p.

- Birdwell, J.E.^{LSU PD}, and Engel, A.S. (2009) Impact of recharge on chromophoric dissolved organic matter in the Edwards Aquifer, Central Texas. Journal of Cave and Karst Studies. 71: 144-156.

- Brannen, K.M.^LSUU , Engel, A.S., and Birdwell, J.E.^{LSU PD} (2009) Extended Abstract: Tracing the origins of chromophoric dissolved matter in karst aquifers, in White, W.B. (ed.), Proceedings of the 15th International Congress of Speleology, vol. 1, symposia part 1, p. 354-359.

- Porter, M.L.*, Engel, A.S.*, Kane, T.C., Kinkle, B.K. (2009) Productivity-diversity relationships from chemolithoautotrophically based sulfidic karst systems.  International Journal of Speleology. 38(1):27-40.
(* equal contribution)

- Landrum, J.T., Bennett, P.C., Engel, A.S., Alsina, M., Pasten, P., Milliken, K. (2009) Partitioning geochemistry of arsenic and antimony, El Tatio geyser field, Chile. Applied Geochemistry, 24: 664-676. doi:10.1016/j.apgeochem.2008.12.024.

- Engel, A.S. (In review) Karst microbial ecosystems. Contribution to the Encyclopedia of Geobiology. Springer Encyclopedia of Earth Science Series (EESS).

- Porter, M.L.⁺  and Engel, A.S. (2008) Diversity of uncultured Epsilonproteobacteria from terrestrial sulfidic caves and springs. Applied and Environmental Microbiology. 74(15):4973-4977.

- Porter, M.L.^{LSU PD}, and Engel, A.S. (2008) Balancing conservation of sulphidic caves and karst with tourism, economic development, and scientific study: Cave and Karst Science. 35:19-24.

- Engel, A.S. and Northup, D.E. (2008) Caves and karst as model systems for advancing the microbial sciences, in Martin, J. and White, W.B. (eds)., Frontiers in Karst Research, Special Publication 13, Karst Waters Institute, Leesburg, Virginia: 37-48. Download entire document for FREE.

- Engel, A.S. and Northup, D.E. (2008) Focus Group on Caves and Karst as Model Systems in Geomicrobiology, in Martin, J. and White, W.B. (eds)., Frontiers in Karst Research, Special Publication 13, Karst Waters Institute, Leesburg, Virginia: 90-95.  Download entire document for FREE

- Engel, A.S., and Bennett, P.C. (2008) Lower Kane Cave, Wyoming: Where biology and geology meet, in Rhinehart, R. (ed.), National Speleological Society Rocky Mountain Section Regional field guide, 43-57.

- Engel, A.S. and K.W. Randall (2008) Microbially enhanced carbonate dissolution in karst aquifers, in Sasowsky, I.D., Feazel, C.T., Mylroie, J.E., Palmer, A.N., and Palmer, M.V., Karst from Recent to Reservoirs, Karst Waters Institute Special Publication 14, 52-56.

- Engel, A.S. ⁺, Lichtenberg, H.^CG, Prange, A., Hormes, J. (2007) Speciation of sulfur from naturally-occurring, filamentous microbial mats from sulfidic cave springs using x-ray absorption near edge spectroscopy. FEMS Microbiology Letters. 269(1): 54-62.

- Engel, A.S. (2007) Observations on the biodiversity of sulfidic karst habitats. Journal of Cave and Karst Studies. 69(1): 187-206.

- Meisinger, D.B.^CG* , Zimmermann, J.^PD* , Ludwig, W., Schleifer, K.-H., Wanner, G., Schmid, M., Bennett, P.C., Engel, A.S., and Lee, N. ⁺ (2007) In situ detection of novel Acidobacteria in microbial mats from a chemoautotrophically-based cave ecosystem. Environmental Microbiology. 9(6): 1523-1534. (* equal contribution)

- Bennett, P.C., and Engel, A.S. (2007) Microbial sulfur cycling in a sulfidic cave: 12^th Water-Rock Interaction: Proceedings of the International Symposium on Water-Rock Interaction (WRI-12), Kunming, China, July 31-August 5, 2007, A.A. Balkema publishers.

- Campbell, B.J.* ⁺, Engel, A.S.* ⁺, Porter, M.L., and Takai, K. (2006) The versatile Epsilon-proteobacteria: Key players in sulphidic habitats. Nature Reviews Microbiology. 4:458-468. (* equal contribution)

- Phoenix, V.R.⁺, Bennett, P.C., Engel, A. S., Tyler, S.W., and Ferris F.G. (2006) Chilean high-altitude hot spring sinters: a model system for UV screening mechanisms by early Precambrian cyanobacteria. Geobiology. 4: 15-28.

- Bennett, P.C., Engel, A.S., Roberts, J.A. (2006) Counting and imaging bacteria on mineral surfaces, in Maurice, P.A., Warren, L.A. (eds.), Methods of Investigating Microbial-Mineral Interactions, CMS Workshop Lectures, Vol. 14, The Clay Mineral Society, Chantilly, VA: 37-77.

- Engel, A.S. (2005) Chemoautotrophy, in Culver, D. and W. White, (eds.) Encyclopedia of Caves. p. 90-102.

- Bennett, P.C., and Engel, A.S. (2005) Microbial contributions to karstification, in Gadd, G.M., Semple, K.T., and Lappin-Scott, H.M. (eds.), Micro-organisms and Earth Systems – Advances in Geomicrobiology, Society for General Microbiology (SGM) Symposium 65, Cambridge University Press: 345-363.

- Engel, A.S. ⁺, Porter, M.L., Stern, L.A., Quinlan, S.^CU, Bennett, P.C. (2004) Bacterial diversity and ecosystem function of filamentous microbial mats from aphotic (cave) sulfidic springs dominated by chemolithoautotrophic “Epsilonproteobacteria”. FEMS Microbiology Ecology. 51: 31-53.

- Engel, A.S. ⁺, Stern, L.A., and Bennett, P.C. (2004) Microbial contributions to cave formation: new insights into sulfuric acid speleogenesis. Geology. 32(5): 369-372.

- Engel, A.S. ⁺, Lee, N., Porter, M.L., Stern, L.A., Bennett, P.C., and Wagner, M. (2003) Filamentous “Epsilonproteobacteria” dominate microbial mats in sulfidic caves. Applied and Environmental Microbiology. 69(9): 5503-5511.

- Engel, A.S. ⁺, Porter, M.L., Kinkle, B.K., and Kane, T.C. (2001) Ecological assessment and geological significance of microbial communities from Cesspool Cave, Virginia. Geomicrobiology Journal. 18:259-274.

- Engel, A.S., Bennett, P.C., and Stern, L.A. (2001) Biogeochemical diversity of microbial mats from Lower Kane Cave, Wyoming, USA, in Weber, J., Jamroz, E., Drozd, J., and Karczewska, A. (eds.) Biogeochemical Processes and Cycling of Elements in the Environment. 15th Int Symposium of Environmental Biogeochemistry, Wroclaw, Poland: p. 135-136.

- Vlasceanu, L., Sarbu, S., Engel, A.S., and Kinkle, B.K. ⁺ (2000) Acidic, cave-wall biofilms from the Frasassi Caves, Italy. Geomicrobiology Journal. 17:125-139.

- Engel, A.S. (2000) Microbially-enhanced weathering in subsurface environments: Sulfur-oxidizing bacteria and the cave environment, in Onac, B. and Tamas, T. (eds.) Karst Studies and Problems: 2000 and Beyond. Friends of Karst Special Meeting. Cluj, Romania: p. 130-134.

COLLECTIONS OF UNPUBLISHED WORK

- Engel, A.S. (2004) Geomicrobiology of Sulfuric Acid Speleogenesis: Microbial Diversity, Nutrient Cycling, and Controls on Cave Formation, PhD dissertation, Department of Geological Sciences, The University of Texas at Austin, Austin, Texas, 375p.

- Engel, A.S. (1999) Geomicrobiology of Sulfidic Karst Systems, MS thesis, Department of Biological Sciences, University of Cincinnati, Cincinnati, Ohio, 88p.

- Engel, A.S. (1997) The Speleogenesis of Movile Cave, Southern Dobrogea, Romania, MS thesis, Department of Geology, University of Cincinnati, Cincinnati, Ohio, 146p.

MISCELLANEOUS NON PEER-REVIEWED WORK

- Engel, A.S., and Engel, S.A.., 2009, A field guide for the karst of Carter Caves State Resort Park and the surrounding area, northeastern Kentucky, in Engel, A.S. and Engel, S.A. (Editors) Select Field Guides to Cave and Karst Lands of the United States. Karst Waters Institute Special Publication 15, 87-109.

- Engel, A.S., Meisinger, D.B.^CG, Porter, M.L.^CPD, Schmid, M., and Lee, N.M. (2009) Caves as model systems for the evolution of a complex biosphere in a chemolithoautotrophic subsurface, Special Issue: Abstracts from the Eighth European Workshop on Astrobiology (EANA): Origins of Life and Evolution of Biospheres (online early) 10.1007/s11084-008-9155-0.

- Engel, A.S. and K.W. Randall (2008) Microbially enhanced carbonate dissolution in karst aquifers, in Sasowsky, I.D., Feazel, C.T., Mylroie, J.E., Palmer, A.N., and Palmer, M.V., Karst from Recent to Reservoirs, Karst Waters Institute Special Publication 14, 52-56.

- Stern, L.A., Engel, A.S., Bennett, P.C., and Porter, M.L. (2002) Subaqueous and subaerial speleogenesis in a sulfidic cave, in Martin, J.B., Wicks, C.M., and Sasowsky, I.D. (eds.) Hydrogeology and Biology of Post- Paleozoic Carbonate Aquifers. Karst Waters Institute Special Publication 7. Gainesville, FL: p. 89-91.

- Engel, A.S. (1999) Don’t drink the water. Electric Caver. 36(3):7.

- Engel, S. and A. Summers Engel (1998) Great Saltpetre Cave, Rockcastle County, Kentucky: a geology and archeology field guide. Electric Caver. 35(3):5-12.

- Summers Engel, A., Sarbu, S., Badescu, A., Lascu, C., Sasowsky, I., and W. Huff. (1997) A study of cave sediment from Movile Cave, Southern Dobrogea, Romania. Proceedings of the 12^th International Congress of Speleology Las Chaux-de-Fonds, Switzerland. Vol. 1: p. 25-28.

- Krekeler, M.P.S., Summers Engel, A., Engel ,S., Mixon, D., and M. Ragsdale. (1997) Sedimentology, clay mineralogy, and geochemistry of cave sediment from Hard Baker Cave, Rockcastle County, Kentucky, USA. Proc. 12^th Int. Congress Speleology - Las Chaux-de-Fonds, Vol. 1: p. 21-24.

- Summers, A. (1996) Small, but interesting caves in Carter County, Kentucky. SpeleoDigest 1995: 119-121.

- Summers, A. (1995) Sulfur bacteria in the spelean environment. Pholeos 15(2):29-39. (reprint 1996, SpeleoDigest 1995: 457-465).

- Summers, A. (1993) Frasier’s pits. Pholeos 13(2): 9.

- Summers, A. (1993) Laurel. Pholeos 13(20):18.

- Summers, A. (1992) Bats and public opinion. Pholeos 12(2):15-18.

CURRENT RESEARCH FUNDING

National Science Foundation

- $278,154 "The Speciation and Behavior of Sulfur Gases in Biogeochemical Processes" EAR-0844364 (ARRA; Geobiology & Low Temperature Geochemistry Program) Collaborative with A. Prange and F.J. Hormes, CAMD, LSU). 7/09-6/13.

- $191,750 “Collaborative Research: Epsilonproteobacteria from Terrestrial Springs and Caves”,  DEB-0640835 (Systematic Biology and Biological Inventories Program) (Sole PI at LSU, collaborative with B.J. Campbell, Univ. Delaware). 4/07-4/10.

- $109,452 "Collaborative Research: Biogeochemical controls on antimony and arsenic mobility in a siliceous hydrothermal system”, EAR-0544960 (Geobiology & Low Temperature Geochemistry Program) (Sole PI at LSU, collaborative with U Texas-Austin). 9/15/06-9/14/09.

Louisiana Board of Regents

- $145,000 Board of Regents “Acquisition of a Variable Pressure Scanning Electron Microscope with Cryostage and EDX for Cell, Developmental and Microbiology Research and Education” PI: J. Larkin; Co-PIs (each with 14% credit):
B. Christner, A.S. Engel, F. Galvez, C. Hart, G. King, and K. Svoboda (Dept. Biological Sciences)

- "$130,100 "Instrumentation Enhancement for Analytical Geochemistry Teaching and Research" Board of Regents Support Fund, Enhancement Component 005-EAR-07(Lead PI, with H. Bao and W. Blanford) 7/1/07-6/30/08.

- “$138,678 Geomicrobiology of the Bad-water Transition Zone of the Edwards Aquifer, Central Texas: Geological and ecological implications of the chemoautotrophically-based groundwater ecosystem”, LEQSF(2006-09)-RD-A-03 (Research Competitiveness Subprogram) (Sole PI) 7/1/06-6/30/09.

- $11,960 “Exploratory Research to Understand the Biogeography and Evolutionary History of Novel “Epsilonproteobacteria” from Terrestrial Sulfur Springs” NSF/LEQSF(2005)-Pfund-04 (Pilot fund for New Research Program). (Sole PI) 2/1/05-1/31/06.

Louisiana State University

- $60,000 Louisiana State University “Opening black boxes: Multiple stable isotope study of denitrifying and sulfate-reducing microorganisms to understand modern and ancient metabolic processes” Flagship Graduate Assistantship (to support a co-advised PhD student with H. Bao, co-PI)

- $10,000 Faculty Research Grant "Sulfur Speciation using XANES Spectroscopy to Interpret Natural Sulfur Biological Signatures” With A. Prange, CAMD. 7/1/07-6/30/08

- $10,000  Faculty Research Grant “Geomicrobiology of the ‘Bad-water’ Transition Zone of the Edwards Aquifer, Central Texas” (Sole PI) 7/1/05-6/30/06.

- $5,000 Council for Research. Summer Stipend Program. “Bad-water microbes in the Edwards Aquifer, Central Texas” (Sole PI) 7/1/05-7/30/05

PARTICIPATION IN PROFESSIONAL MEETINGS & CONFERENCES

⁺ Corresponding Author; ^CG Collaborator Graduate Student; ^LSUG LSU Grad Student;
^LSUU LSU Undergraduate; ^{LSU PD} LSU Collaborating Post-doc

2009 (See listing of accepted extended abstracts that are >2 pages)
-  Brannen, K.M.^LSUU, Engel, A.S., and Birdwell, J.E., ^{LSU PD} Extended Abstract: Tracing the origins of chromophoric dissolved matter in karst aquifers. Geomicrobiology of Cave and Karst Environments Symposium, International Congress of Speleology meeting, Kerrville, Texas, July 19-26 (poster presentation)
- Oarga, A.^CG, Mulec, J. ^{CPD/ LSU PD}, Sebela, S., Rossmassler, K. ^CG, Campbell, B.J., Engel, A.S. Microbial diversity from the sulphidic karst spring, Žveplenica-Dolenja Trebuša, Slovenia. Geomicrobiology of Cave and Karst Environments Symposium, International Congress of Speleology meeting, Kerrville, Texas, July 19-26 (oral presentation)
- Porter, M.L ^{CPD/ LSU PD}., and Engel, A.S. Energy flow and productivity-diversity relationships in chemolithoautotrophically-based ecosystems. Geomicrobiology of Cave and Karst Environments Symposium, International Congress of Speleology meeting, Kerrville, Texas, July 19-26 (oral presentation)
- Meisinger, D.B. ^CG, Engel, A.S., Porter, M.L. ^CPD, Schmid, M., and Lee, N.M. The hunt for hidden biodiversity and novel functional groups: a case study of unique Chloroflexi affiliated species and other novel species from Lower Kane Cave, WY. USA. Geomicrobiology of Cave and Karst Environments Symposium, International Congress of Speleology meeting, Kerrville, Texas, July 19-26 (oral presentation)
- Franks, M^CG, Omelon, C.^CPD, Engel, A.S., Bennett, P.C. Correlations between archaeal diversity and geochemical parameters in an arsenic-rich hydrothermal system: 2009 EGU General Assembly, Geophysical Research Abstracts, 11: EGU2009-0.
- Rossmassler, K.^CG, Engel, A.S., Campbell, B.J. 23S rRNA phylogenies and whole genome amplification reveal increased diversity among Epsilonproteobacteria from sulfidic caves and springs. American Society for Microbiology meeting, Philadelphia, PA, May.

2008
- Engel, A.S., Meisinger, D.B.^CG, Porter, M.L., Lee, N.M. Microbial mats in caves as model systems for the evolution of a complex biosphere in a chemolithoautotrophic subsurface. International Kalkowsky-Symposium "Geobiology of Stromatolites," University of Göttingen, Germany. October 4th-11th (poster presentation).
- Birdwell, J.E.^PD, Schulz, C.^LSUG, Engel, A.S.*, Chromophoric dissolved organic carbon from cave and karst waters. International Symposium for Subsurface Microbiology, Shizouka, Japan, November 16-21. (oral presentation).
- Engel, A.S., Meisinger, D.B.^CG, Porter, M.L., Schmid, M., Lee, N.M. Caves as model systems for evolution of a complex biosphere in a chemolithoautotrophic subsurface area. 8th International Workshop European on Astrobiology EANA, Neuchâtel, Switzerland, Sept 1-3. (poster presentation)
- Rossmassler, K.^CG, Engel, A.S., Campbell, B.J., Biogeography and phylogeny of Epsilonproteobacteria in sulfidic environments. International Symposium for Subsurface Microbiology, Shizouka, Japan, November 16-21 (oral presentation).
- Engel, A.S.*, Birdwell, J.E.^PD Johnson, L.^LSUG, Brannen, K.M.^LSUU, Franks, M.^CG, Omelon, C.R.^PD, Landrum, J.T.^CG, Alsina, M.A.^CG, Pasten, P.A., Bennett, P.C. Biofilm development, microbial diversity, and dissolved organic matter from El Tatio, Chile: implications for metalloid biogeochemical cycling. (Invited oral presentation by P.J. Boston, Biofilms and Biomineralization) Houston, TX, Oct. 5-9, Geological Society of America meeting Abstracts with program.
- Engel, A.S.*, Northup, D.E., Boston, P.J. (2008) Role of microbes in hypogenic karst development and modification. Houston, TX, Oct. 5-9, Geological Society of America meeting Abstracts with program.
- Northup, D.E., Boston, P.J., Hughes, K., Clement, A., Engel, A.S. (2008) Biofilm central: the wonderland of textures and bacterial and archaeal communities in Cueva De Villa Luz. Houston, TX, Oct. 5-9, Geological Society of America meeting Abstracts with program.
- Engel, A.S.*, Beggio, M.^CU, Pamio, A., Dreon, A.L., Dorigo, L., Paoletti, M.G. Implications of bacterial diversity and activity in carbonate deposits, Bus de la Foos Cave, Italy, in Zupan Hajan, N., and Mihevc, A. 16th International Karstological School “Classical Karst”, Karst Sediments. Karst Research Institute, Postojna, Slovenia, p. 69-70.
- Engel, A.S.* and K.W. Randall (2008) Microbially enhanced carbonate dissolution in karst aquifers, “Karst from Recent to Reservoirs” International Conference on Paleokarst & Multi-permeability Flow Systems.” Rapid City, South Dakota (Invited oral presentation).
- N. Lee, D.B. Meisinger ^CG, M. Pavlekovic, H.J. Busse, A. Summers Engel, G.M. Garrity, C.M. Henk, R. Rossello-Mora, K.-H. Schleifer, S. Spring, B. Tindall, F.E. Löffler (2008) Biogeography, ecology, and phylogeny of the Phylum Chloroflexi – isolation and description of novel taxa from different environments. The 12th International Symposium on Microbial Ecology, Cairns, Australia, August 17-22.

2007
- Birdwell, J. ^{LSU CG}, Schulz, C. ^LSUG, and Engel, A.S. (2007) Autochthonous dissolved organic matter in karst waters: Evidence from fluorescence spectroscopy. American Geophysical Union, San Francisco, CA. December (oral presentation).
- Garcia, A. ^LSUG, Thiessen, M.^LSUU, Aronowsky, A.^{LSU PD}, Anderson, L., Bao, H., and Engel, A.S. (2007) Evolutionary implications of endosymbiont diversity within lucinid bivalves. American Geophysical Union, San Francisco, CA. December (poster presentation).
- Peng, Y. ^{LSU CG}, Bao, H., Anderson, L.C., Engel, A.S. (2007) Carbonate-associated sulfate in lucinid (Bivalvia) shells. American Geophysical Union, San Francisco, CA. December (poster presentation).
- Schulz, C.^LSUG, and Engel, A.S. (2007) Relating microbial gene sequences to environmental factors: Cutting through the trees. Geological Society of America meeting, Denver, CO, October (Poster presentation).
- Green Garcia, A.^LSUG, Thiessen, M.^LSUU, Aronowsky, A.^{LSU PD}, Anderson, L., and Engel, A.S. (2007) Implications of bacterial diversity within a modern lucinid bivalve habitat. Geological Society of America meeting, Denver, CO, October (Poster presentation).
- Engel, A.S.*, Prange, A., Lichtenberg, H.^CG, Hormes, J. (2007) Understanding natural sulfur biosignatures from sulfidic spring microbial mats based on XANES spectroscopy, microbial diversity, and stable isotope systematics. Geological Society of America meeting, Denver, CO, October (Invited oral presentation).
- Birdwell, J.^CG, Schulz, C.^LSUG, and Engel, A.S.* (2007) Microbially-derived carbon in karst waters. National Speleological Society convention, Marengo, Indiana (Oral presentation).
- Engel, A.S.*, Porter, M.L., and Campbell, B.J. (2007) Karst as a model system to examine terrestrial microbial biogeography patterns through time: An example from the Epsilonproteobacteria. Acta Carstologica, 36(1): 212-213. Proceedings of Time in Karst meeting, March, 2007, Karst Waters Institute, Postojna, Slovenia (Poster presentation).

2006
- Schulz, C.J.^LSUG, Childers, G.W., Engel, A.S. (2006) Molecular investigations of Bacteroides as microbial source tracking tools in southeast Louisiana watersheds. American Geophysical Union meeting, San Francisco, CA (poster presentation).
- Landrum, J.T.^CG, Engel, A.S., Milliken, K., Bennett, P.C. (2006) Biogeochemistry of antimony and arsenic in hydrothermal fluids and opaline deposits from El Tatio geyser field, Chile. Geological Society of America Abstracts with Programs, Vol. 38, No. 7, p. 546 (poster presentation)
- Engel, A.S., Lichtenberg, H.^CG, Prange, A., Hormes, J. (2006) Sulfur speciation in naturally occurring filamentous microbial mats from sulfidic springs: A XANES spectroscopy study. International Symposium on Microbial Sulfur Metabolism, Münster, Germany. Conference Book, p. 134-135. (Poster presentation)
- Engel, A.S.*, and Randall, K.W.^LSUG (2006) Microbial colonization and weathering of carbonates in deep subsurface settings. International Mineralogical Association, Kobe, Japan, p. 248. (Invited oral presentation)
- Reger, R.^LSUG, Porter, M.L., Menichetti, M., Engel, A.S. (2006) Diversity comparisons between microbial mats and endosymbiont gut communities associated with the cave-dwelling Androniscus dentiger (Isopoda: Oniscidae) from the Frassasi Caves, Italy. National Speleological Society Convention. Convention Program Guide, Bellingham, WA, p. 100.
- Engel, A.S.*, Porter, M.L. (2006) Epsilonproteobacteria in terrestrial cave and springs with sulfidic water. National Speleological Society. Convention Program Guide, Bellingham, WA, p. 100-101.
- Randall, K.W.^LSUG, and Engel, A.S.* (2006) Microbially enhanced carbonate dissolution in the Edwards Aquifer of Central Texas. National Speleological Society. Convention Program Guide, Bellingham, WA, p. 71-72.

2005
- Meisinger, D.^CG, Lee, N., Engel, A.S., Bennett, P.C. (2005). Geomicrobiology: Caves as portals to novel, chemoautotrophic ecosystems in the subsurface. Environmental Microbiology meeting, Münich, Germany. MEM_05, Program-Abstracts, p. 22. (Poster contribution)
- Randall, K.W.^LSUG, Johnson, L.^LSUU, and Engel, A.S. (2005) Assessing the potential impact of microbes in the Edwards and Trinity aquifers of Central Texas. GSA Abstracts with Program, v. 37, p. 217. (Poster presentation)
- Engel, A.S.*, and Porter, M.L. (2005) Exploring the microbial diversity of sulfidic karst springs and evaluation of microbial indicator species. GSA Abstracts with Program, v. 37, p. 326. (Oral presentation)
- Engel, A.S.*, Porter, M.L., and Northup, D. (2005) Transcontinental distribution of novel “Epsilonproteobacteria” in terrestrial caves and springs with sulfidic waters, in Program and Abstracts of the Joint International Symposia for Subsurface Microbiology (ISSM 2005) and Environmental Biogeochemistry (ISEB XVII): Jackson Hole, WY. ASM, Washington, D.C., p. 77. (Poster presentation)
- Landrum, J.^CG, Engel, A. S., Milliken, K., Lansdown, J., Bennett, P. C. (2005) Distribution of antimony in silica geyserite from El Tatio, Chile, in Program and Abstracts of the Joint International Symposia for Subsurface Microbiology (ISSM 2005) and Environmental Biogeochemistry (ISEB XVII): Jackson Hole, WY. ASM, Washington, D.C., p. 64-65. (Oral presentation)
- Meisinger, D.^CG, Engel, A.S., Lee, N., Porter, M.L., Stern, L.A., Bennett, P.C. (2005) Molecular and functional diversity of anaerobic metabolic guilds in aphotic redox-stratified microbial mats from Lower Kane Cave, Wyoming in Program and Abstracts of the Joint International Symposia for Subsurface Microbiology (ISSM 2005) and Environmental Biogeochemistry (ISEB XVII): Jackson Hole, WY. ASM, Washington, D.C., p. 120. (Poster presentation)
- Zimmermann, J.^CP, Engel, A.S., Meisinger, D.^CG, Porter, M.L., Stern, L.A., Bennett, P.C., Ludwig, W., Schleifer, K.-H., Lee, N. (2005) Acidobacterial diversity in filamentous microbial mats from Lower Kane Cave, Wyoming, in Program and Abstracts of the Joint International Symposia for Subsurface Microbiology (ISSM 2005) and Environmental Biogeochemistry (ISEB XVII): Jackson Hole, WY. ASM, Washington, D.C., p. 57. (Poster presentation)

2004
- Engel, A.S.* (2004) “Epsilonproteobacteria” in microbial mats from terrestrial caves and springs with sulfidic waters. 2^nd Okazaki Biology Conference on Terra Microbiology. Ohmori, M., and Tiedje, J.M. (eds.), p. 24-25. (Oral presentation)
- Mabin, K.^CG, Engel, A.S., Stern, L.A., Bennett, P.C. (2004) Sulfur dynamics in a sulfidic cave system. GSA Abstracts with Program Meeting, Denver, CO. (Poster presentation)
- Engel, A.S.*, Stern, L.A., Bennett, P.C. (2004) Microbial controls on sulfuric acid speleogenesis. J. Cave and Karst Studies. v. 66, p. 112. (Oral presentation, National Speleological Society meeting, Marquette, Michigan)
- Bennett, P.C., Engel, A.S., Mabin, K.^CG, Stern, L.A. (2004) Sulfur gas dynamics in a sulfidic cave aquatic system. Goldschmidt Conference, Copenhagen, Denmark. (Oral presentation)

2003
- Stern, L.A., Engel, A.S., Bennett, P.C. (2003) Nitrogen isotope evidence of ammonia vapor assimilation by cave wall microbial biofilms in a sulfidic cave, a novel mechanism of nutrient acquisition. Eos Trans. AGU 84(46), Fall meeting Suppl, San Francisco, CA, B42E-05. (Oral presentation)
- Edwards, M.E.^CG, Bennett, P.C., Engel, A.S. (2003) Geochemical and isotopic constraints on the source of groundwater to Lower Kane Cave, Wyoming. Eos Trans. AGU 84(46), Fall meeting Suppl, San Francisco, CA, H21D-0880. (Poster presentation)
- Mabin, K.^CG, Bennett, P.C., Stern, L.A., Engel, A.S. (2003) Microbial influence on sulfur speciation in Lower Kane Cave, WY. Eos Trans. AGU 84(46), Fall meeting Suppl, San Francisco, CA, B51C-0973. (Poster presentation)
- Engel, A.S.*, Stern, A., and Bennett, P.C. (2003) The secret to sulfuric acid speleogenesis. GSA Abstracts with Program, Seattle, WA. (Oral presentation)
- Phoenix, V. R.^CP, Bennett, P.C., Engel, A. S., Tyler, S.W., and Ferris F.G. (2003) Chilean high-altitude hot spring sinters: a model system for UV screening mechanisms by early Precambrian cyanobacteria. GSA Abstracts with Program, Seattle, WA. 35(6): 245. (Oral presentation)
- Engel, A.S.*, Stern, A., and Bennett, P.C. (2003) Condensation on cave walls: Implications for cave enlargement and sulfuric acid speleogenesis. Goldschmidt Conference, Kurishiki, Japan. Geochimica et Cosmochimica Acta: p. A455. (Oral presentation)
- Engel, A.S.*, Bennett, P.C., Stern, L.A. (2003) Volatile organosulfur gas production from aphotic (cave) sulfur-based microbial communities. 16^th International Symposium of Environmental Biogeochemistry. Oirase, Aomori Prefecture, Japan: p. 184. (Poster presentation)
- Engel, A.S.*, Bennett, P.C., and Stern, L.A. (2003) Consequences of low pH, cave-wall condensation and biofilm development to sulfuric acid speleogenesis. National Speleological Society meeting Guidebook, Porterville, CA: p. 8-95. (Poster presentation)

2002
- Engel, A.S.*, Stern, L.A., and Bennett, P.C. (2002) Sulfur cycling and nutrient spiraling in the terrestrial subsurface. GSA Abstracts with Program, Denver, CO, p. 223.  (Oral presentation)
- Bennett, P.C., Engel, A.S., and Rogers, J.R. (2002) Microbes, microbial ecology, and the mineral surface. The Geological Society William Smith Meeting-Life in Earth-Energy, Minerals, Mars and the Deep Biosphere meeting. London, England. (Oral presentation)
- Engel, A.S.*, Bennett, P.C., Stern, L.A., Porter, M.L., Lee, N., and Wagner, M. (2002) Epsilon-Proteobacterial diversity from sulfidic cave springs. International Symposium for Subsurface Microbiology, Copenhagen, Denmark, p. 33-34. (Oral presentation)
- Stern, L.A., Engel, A.S., and Bennett, P.C. (2002) In situ calcite dissolution by sulfur-oxidizing bacteria in a limestone cave. Int. Symposium for Subsurface Microbiology, Copenhagen, Denmark, p. 34. (Oral presentation)
- Bennett, P.C., Engel, A.S., and Rogers, J.R. (2002) Microbial ecology of mineral surfaces. International Mineralogical Association. Edinburgh, Scotland. p. 171. (Oral presentation)
- Engel, A.S.*, Porter, M.L., Stern, L.A., and Bennett, P.C. (2002) Diversity of chemoautotrophic sulfur-oxidizing bacteria in sulfidic caves. Journal of Cave and Karst Studies, 64:180. (Oral presentation, National Speleological Society meeting, Camden, Maine)
- Porter, M.L., Russell, S.^CU, Engel, A.S., and Stern, L.A. (2002) Population studies of the endemic snail Physa spelunca (Gatropoda:Physidae) from Lower Kane Cave, WY. J. Cave Karst Studies, 64:181. (Oral presentation, National Speleological Society meeting, Camden, Maine)
- Bennett, P.C., Engel A.S.*, and Stern, L.A. (2002) Microbial processing of sulfur gases from a terrestrial cave ecosystem: 2^nd Astrobiology Conference, NASA Ames Research Center, CA: p. 189. (Poster presentation)

2001
- Engel, A.S.*, Bennett, P.C., and Stern, L.A. (2001) Sulfuric acid speleogenesis: microbial karst and microbial crust. Eos Trans. AGU 82(47), Fall meeting Suppl, San Francisco, CA, B22E-05. (Oral presentation, received Best Student Paper Award, Biogeochemistry section)
- Stern, L.A., Bennett, P.C., and Engel, A.S. (2001) Organic sulfur gas production in sulfidic caves. Eos Trans. AGU 82(47), Fall meeting, San Francisco, CA, B32C-08.

2000
- Engel, A.S.*, Bennett, P.C., and Stern, L.A. (2000) Mineralogic and geochemical consequences of microbial habitat modification in sulfidic karst systems: Examples from the Kane Caves, Wyoming. Eos Trans. AGU 81(48), Fall meeting Suppl, San Francisco, CA, B71B-04. (Poster presentation, received Best Student Paper Award, Biogeochemistry section)
- Engel, A.S.* (2000) Geomicrobiology of sulfidic karst systems. J. Cave and Karst Studies, 62:35. (Oral Presentation at National Speleological Society meeting)
- Engel, A.S.*, Porter, M., and Shapiro, V. (2000) Ecological and geological significance of microbial communities in a sulfidic cave. J. Cave and Karst Studies, 62:31-32. (Oral presentation)

1999
- Engel, A.S.* (1999) Microbiological impacts on the development of subsurface porosity in sulfidic karst systems. American Association of Petroleum Geologists (AAPG) Bulletin, 83:1885. (Abstract publication)
- Engel, A.S.* and B. Kinkle. (1999) Chemoautotrophic bacteria and their role in development of sulfidic groundwater systems. GSA Abstracts with Programs, Denver, CO: 31(7):935. (Poster presentation)

1998
- Badescu, A., Sarbu, S., and Engel, A.S. (1998) Preliminary geochemical investigations on the Mangalia aquifer(s), Romania. GSA North-Central Section Abstracts with Programs, Columbus, OH: 30(2):3. (Poster presentation)
- Krekeler, M.P.S., Grover, J., Potter, P., and Engel, A.S. (1998) Dissolutional features associated with a small thrust fault, Maysville, Mason County, Kentucky: a study to connect regional structural and geomorphic histories. GSA Southeastern Section Abstracts, Charleston, WV: 30(4):22. (Poster presentation)

1997
- Engel, A.S.* (1997) Microorganisms and condensation corrosion: a discussion of dolomite, its occurrence in caves, and possible microbial mediation. National Speleological Society Convention Guidebook, Sullivan, MO: p. 60-61. (Poster presentation)
- Engel, A.S.* and S. Engel. (1997) The forgotten karst of northeastern Kentucky: a case study of regional speleogenesis in Carter Caves State Resort Park. NSS Guidebook, Sullivan, MO: p. 62. (Oral presentation)
- Mixon, D., Morton, C., Ragsdale, M., Helfin, D., Krekeler, M.P.S., and Engel, A.S. (1997) Characteristics of clastic cave sediment from Great Saltpetre Cave, Rockcastle County, Kentucky. The Ohio Journal of Science, 97(2):20. (Poster presentation; all authors graduate or undergraduate students)

1996
- Engel, A.S.* and Lascu, C. (1996) Clays from Movile Cave, Southern Dobrogea, Romania: speleohistoric indicators of cavern formation. Clays and Clay Minerals Society Annual Meeting, Programs and Abstracts. Gatlinburg, TN: p. 53. (Oral presentation)
- Engel, A.S.* (1996) Scanning electron microscopy of fine-grained sediment from Movile Cave, Southern Dobrogea, Romania. NSS Meeting Guidebook, Salida, CO: p. 44. (Oral presentation, received James Mitchell Award for Best Student Talk)
- Engel, A.S.*, Huff, W., Badescu, A., Lascu, C., and S. Sarbu (1996) Sediment studies from Movile Cave, South Dobrogea, Romania. GSA Abstracts with Programs, Denver, CO: p. 281. (Poster presentation)
- Mixon, D., Ragsdale, M., Engel, A.S., Krekeler, M.P.S., Mickler, P., and S. Engel (1996) Clay mineralogy of some clastic cave deposits from Great Saltpetre Cave, Kentucky: detrital and authigenic minerals. Geological Society of America Abstracts with Programs, Denver, CO: p. 307.  (Poster presentation, all authors undergraduate or graduate students)

1995
- Summers, A.* and H.H. Hobbs (1995) Jointing and bedding plane controls on cave passage development, Canyon Cave, Carter County, Kentucky. The Ohio Journal of Science, 95(2):52. (Oral presentation to Ohio Academy of Sciences, Columbus, Ohio)

INVITED PRESENTATIONS & WORKSHOP PARTICIPATION

- May 22, 2009. Invited speaker, University of Delaware, College of Marine and Earth Sciences, "Endosymbiont diversity from lucinids in Thalassia  (turtlegrass) siliciclastic sediments, Florida and The Bahamas"
- May 19, 2009. Invited Speaker at American Society for Microbiology conference, "Geological Consequences from Microbial Diversity & Primary Productivity in Karst" in session "Geobiology: Microorganism-Rock Interactions from the Deep Subsurface Through the Rock Record." Philadelphia, PA.
- June 7-11, 2008. Karst Waters Institute, “Karst from Recent to Reservoirs: International Conference on Paleokarst & Multi-permeability Flow Systems.” Rapid City, South Dakota  “Microbially Enhanced Carbonate Dissolution in Karst Aquifers” (invited talk)
- April 11, 2008 LSU, Dept. Geology & Geophysics. “Sulfur Cycle Secrets Revealed: New Insights from Synchrotron-based Spectroscopy and Molecular Genetics” (seminar talk)
- June 11, 2007. Bexar Grotto, San Antonio, Texas. “Valvasor…” (informal talk to cave group)
- May 3, 2007. Future Directions in Karst Research Workshop, Karst Waters Institute, San Antonio, Texas. “Caves and Karst Aquifers as Model Systems for Advancing the Field of Geomicrobiology” (Workshop presentation)
-  February 13, 2007. Science Club, LSU. “Rock-eating Bugs: The Caves that Microbes Built” (General talk)
- January 11, 2007. Edwards Aquifer Authority, San Antonio, Texas. “Microbial Diversity of the Edwards Aquifer Saline-Water: Implications for Microbially Enhanced Carbonate Dissolution” (Invited Brown Bag talk)
- November 1, 2006. Univ. Alabama, Dept. Geological Sciences. “Microbial Colonization and Weathering of Carbonates in Deep Subsurface Settings” (Invited Departmental Seminar talk).
- October 20-24, 2006. “Slovenian-US Workshop on Long Term Ecological Studies in the Slovenian Karst”. Postojna, Slovenia. Workshop participation funded by NSF (Dave Culver and Tanja Pipan, PIs).
- September 29, 2006. Southeastern Louisiana University, Dept. Biology. “Novel Epsilonproteobacteria from Terrestrial Caves and Springs” (Invited Departmental Seminar talk)
- July 23-28, 2006. International Mineralogical Association conference, Session 24 (Bio-Geo interface in Minerals), Kobe, Japan. “Microbial Colonization and Weathering of Carbonates in Deep Subsurface Settings” (Invited Conference talk; published abstract)
- October 13, 2005. Center for Advanced Microstructures and Devices (CAMD), LSU. “Better than Lotion: Using Hydrothermal Sinter Deposits to Understand How Early Precambrian Cyanobacteria Protected Themselves against UV Radiation” (Invited Organization Seminar talk)
- June 17, 2005. Edwards Aquifer Authority, San Antonio, Texas. “Geological Consequences of Chemolithoautotrophically-based Terrestrial Ecosystems” (Invited Brown Bag talk)
- February 24, 2005. Oregon State University, Subsurface Biosphere Program. “Geological Consequences of Chemoautotrophically-based Terrestrial Ecosystems” (Invited talk for IGERT seminar series with Oregon St. Univ. and Portland St. Univ.)
- January 12, 2005. Universidad Católica, Santiago, Chile. Department of Engineering and Hydrology. “Geomicrobiology of El Tatio, Chile: UV Screening Mechanisms by Early Precambrian Cyanobacteria” (Invited Departmental Seminar talk)
- November 19, 2004. Louisiana State University, Dept. of Oceanography. “Biogeochemical Cycling in Chemoautotrophically-based Terrestrial Ecosystems” (Departmental Seminar talk)
- September 27-30, 2004. 2nd Okazaki Biology Conference on “Terra Microbiology”. Okazaki, Japan. “Distribution of Novel “Epsilonproteobacteria” in Microbial Mats from Terrestrial Caves and Springs with Sulfidic Waters” (Invited Conference talk, all-expenses paid for workshop)
- March 5, 2004. McMaster University, Department of Geology. “New Insights into the Role of Microorganisms in Sulfuric Acid Speleogenesis” (Invited Departmental Seminar talk)
- March 4, 2004. University of Windsor, Department of Geology “New Insights into the Role of Microorganisms in Sulfuric Acid Speleogenesis” (Invited Departmental Seminar talk)
- January 27, 2004. University of Kansas, Department of Geology (Invited Departmental Seminar talk) “Biogeochemical Cycling in Chemoautotrophically-based Terrestrial Ecosystems”
- November 19, 2003. The University of Texas at Austin, Student Speleological Society meeting. “Geomicrobiology of Sulfidic Caves” (Invited Organization talk)
- October 2002. Brigham Young University, Department of Integrative Biology “Geomicrobiology of Sulfidic Cave Springs” (Invited Departmental Seminar talk)
- March 2002. Lehrstuhl für Mikrobiologie, Technische Universität, Freising, Germany “Biogeochemical Diversity of Lower Kane Cave, Wyoming” (Invited Seminar talk while being a Visiting Research Scientist, February - March 2002)

ACTIVE STUDENT DISSERTATIONS & THESES DIRECTED

Ph.D. Dissertations (link to student research descriptions and pictures)

1) Brendan Headd, Dept. Geology & Geophysics. (2009 - present)

2) Sarah Keenan, Dept. Geology & Geophysics. (August, 2009 -present)

3) Chang Liu, Dept. Geology & Geophysics (August, 2009 - present)

4) Changjie Liu, Dept. Geology & Geophysics. Co-advised with Dr. Huiming Bao (August, 2009-present)

M.S. Theses (link to student research descriptions and pictures)

1) Lindsey Johnson, Dept. Geology & Geophysics. (2008 - present) Tentative thesis title: “Geochemistry and bioavailability of arsenic and antimony  in El Tatio Geyser Field, Chile” L. Johnson received $3000 from the American Association for Petroleum Geologists  John Teagle Memorial Grant  (April, 2009).

2) Cassie Gray, Dept. Geology & Geophysics. (2008 - present)  Tentative thesis title: “Microbial diversity and carbonate dissolution along a geochemical gradient in the Edwards Aquifer, Texas” C. Gray received $1000 from the Karst Waters Institute for a William L. Wilson Scholarship in Karst Science (March, 2009) and American Association for Petroleum Geologists Edward B. Picou Named Grant ($3000) (April, 2009).           

3) Eric Prokocki, Dept. Geology & Geophysics (2008 - Dec. 2009) (acting co-advisor with Dr. M. Blum, ExxonMobil) Thesis title: "A new model for the Holocene evolution of the lower Mississippi River developed from palaeohydrological estimations and Optically Stimulated Luminescense dating: Yazoo Basin, MS"

4) Matt Garvin, Dept. Geology & Geophysics (2008) (acting co-advisor with Dr. M. Blum, ExxonMobil) Thesis title: “Late Quaternary Geochronologic, Stratigraphic, and Sedimentologic Framework of the Trinity River Incised Valley: East Texas Coast”

5) Angela Green-García, Dept Geology & Geophysics. (2005 - present) Thesis title: “Characterization of the lucinid bivalve-bacteria symbiotic system: the significance of the geochemical habitat on bacterial symbiont diversity and phylogeny” (Provisional title; in progress).  A. G.-García is funded through GAEMP. She received $1000 from the Sigma Xi Grants-in-Aid (April 2007). Graduated May, 2008.

6) Kelli D. Willson Randall, Dept Geology & Geophysics. (2004 - 2006) “Microbially mediated carbonate dissolution in the Edwards Aquifer, Texas” (Completed May, 2006)  K. Willson received $200 from Sigma Xi Grants-in-Aid (April 2005) and $2000 from the South Texas Geological Society (June 2005) for her research. Accepted internship with Marathon Oil Company, Houston, Texas, summer 2006. Employed full-time at Marathon Oil Company, Texas.
 

For information related to Undergraduate Research, and University and Professional Service, please contact Dr. Engel.