Louisiana State University
Dr. Annette Summers Engel
E235 Howe-Russell Geoscience Complex
Louisiana State University
Baton Rouge, LA 70803
office: 225-578-2469 fax: 225-578-2302
GEMS
RESEARCH GROUP
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Geomicrobiologist |
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| CURRENT LAB MEMBERS & FACES | |||
 LSU GEMS Grad Students, Nov. 2009 |
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Lindsey Johnson Masters Thesis Project: Lindsey is studying arsenic biogeochemical cycling from El Tatio geyser field in northern Chile. Microbes utilize metals for energy, so by studying the microbial diversity, natural and simulated As speciation and geochemical changes, the reactions influencing microbial metabolism can be determined. She has been working on the microbial diversity, dissolved organic matter chemistry, and metal speciation using a variety of methods, including ATR-FTIR and synchrotron-based approaches at CAMD (XANES and EXAFS). Her tentative thesis title is “Geochemistry and bioavailability of arsenic in El Tatio Geyser Field, Chile.” The results will be potentially important to alternative geothermal energy development engineering applications, metals management, and global efforts to remediate As in drinking water. |
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Cassie Gray Masters Thesis Project: Tentative thesis title: “Microbial diversity and carbonate dissolution along a geochemical gradient in the Edwards Aquifer, Texas”. Previous work found that H2S-utilizing microbes in the saline water zone produce sulfuric acid and enhanced carbonate dissolution rates above abiotic geochemical reaction rates. But, the potential effects of microbially-induced carbonic acid dissolution in the freshwater portion of the aquifer are not known, and it is not clear how much carbonic acid dissolution there is in the saline water zone, or how microbially-induced dissolution rates differ between the saline and freshwater. Cassie is also evaluating the taxonomic and functional diversity of dominate microbial groups along the geochemical gradient. |
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Brendan Headd PhD Dissertation Project: Tentative title: "The Role of Extracellular Polymeric Substances in Microbial Mat Structure and Function." Few studies have attempted to identify how the different varieties of EPS produced in biofilms regulate the chemistry and biology of a microbial community, or influence the interactions of microbes on their environment. Variants of EPS will promote specific functions that can affect the whole community. Some of the research questions include: how does the type of chemistry of EPS vary among different types of microbial mats and biofilms, especially those dominated by specific groups of microbes? How specific are EPS varieties for binding inorganic and organic constituents? How does binding influence the spatial, ecological, and chemical composition of a mat? How effective is EPS at preventing potential nutrients and metabolic byproducts from escaping a biofilm? |
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Kathleen Brannen Chancellor's Student Aide & "Napoleon" Observing the behavior of people working on stressful and demanding experiments is an interesting aspect of this job. Kathleen is primarily responsible for making sure the water system is refreshed and uncontaminated, for keeping the lab clean, organized, and without clutter, unpacking packages, maintaining the chemical and instrument inventories, checking calibrations of various instruments, bibliographic data entry, and making sure that everyone does their lab duties. Kathleen also helps people accomplish research tasks, and is fast becoming the lab mini-prep expert. |
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Brendan Donnelly Chancellor's Student Aide and "Spec Master"
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Chang Liu Research Interests: Chang is quite interested in the geomicrobiology of cave and karst systems.
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Sarah Keenan Research Interests: Sarah's research interests in geology include vertebrate paleobiology, taphonomy, sedimentary geology, geochemistry, and geomicrobiology. Her undergraduate research on the first-described Triceratops bonebed from the Hell Creek Formation of Montana, allowed her to combine field-based geology skills towards vertebrate paleontology. She has spent the past three field seasons in the Badlands of Montana, collecting taphonomic data with the Museum of the Rockies, part of Montana State University, on many dinosaur sites. Her most recent work, as part of her MS thesis at the University of Bristol, related to rare earth elements in dinosaur bones, and how that can be used to understand the process of fossilization. Currently, she is continuing to develop interests in bone taphonomy, and is investigating the role of microorganisms in the fossilization process, as well as continuing to explore bone geochemistry. |
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Skylar
White |
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Audrey
Patterson |
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Teresa Brown |
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| FORMER LAB MEMBERS & GRADUATES | |||
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Justin Birdwell, Ph.D. Justin is currently working at the USGS on a Mendenhall Research fellowship, which is an opportunity for postdoctoral researchers to conduct research in association with USGS staff. He is at the Boulder, CO, office. At LSU, Justin's interests were pretty diverse, and with the GEMS group he studied organic geochemistry, and particularly the properties of chromophoric dissolved organic matter. |
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Kelley Gwin Kelley studied lucinid bivalve clam symbiosis, focusing on the diversity of different genes associated with the bacterial metabolism. |
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Angela Green-Garcia |
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Kelli Willson Randall |
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Maureen Thiessen Chancellor's Student Aide |
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