Sarah Hensley

Education

• B.S., Biology, Southwestern University, Georgetown, TX

Research description

The effects of increasing atmospheric CO2 concentrations include mild rises in sea level and uncontrolled global warming. To lower existing levels of atmospheric CO2, we must access untapped renewable resources, such as solar power. To become competitive with wind and hydro-power, solar energy requires an efficient means of energy storage.

Energy storage in carbon-to-carbon bonds represents an energy dense means of storage that can be integrated into existing infrastructure. It can be achieved through photosynthesis or electrosynthesis. Electrosynthesis produces organic compounds via the same net reaction as photosynthesis: carbon dioxide and water are converted to organic compounds and oxygen. However, the energy source for electrosynthesis is electricity, which may ultimately come from sunlight through photovoltaics. Electrosynthesis is more efficient than photosynthesis because energy flow is primarily diverted to product rather than excess biomass. Microbial electrosynthesis (ME) offers myriad advantages over abiotic catalysts, including decreased toxicity and cost, as well as the ability to produce specific products at high efficiency. Although ME traditionally was researched as a means to produce hydrogen, it also presents a path toward fossil-fuel independent organic compound production. Acetogens represent potentially attractive catalysts for ME because they already contain the Wood-Ljungdhal pathway for carbon dioxide reduction, allowing for carbon dioxide sequestration into organic compounds. Many acetogens also have genetic systems available and exhibit a diversity of metabolisms. Moreover, acetogens have recently been shown to be capable of ME from a graphite electrode. However, it is currently unknown how acetogens are capable of converting electrons and carbon dioxide into organic compounds. In order to determine what physiological components are key to an efficient means to store solar energy in organic compounds, we seek to examine the system preference, metabolic activity, and gene expression of acetogens in a ME system.

Publications

• In revision. Burks, R.L, S.A. Hensley, M.K. Trawick, C.H. Kyle. "Quite the appetite: juvenile island apple snails (Pomacea insularum) feed selectively on three invasive plants." Aquatic Ecology.

Presentations

• Hensley, S.A., Z.M. Summers, A.E. Franks, K.P. Nevin, D.R. Lovley. Optimization of Microbial Electrosynthesis with Clostridia ljungdahlii. ISME. 2010.
• Hensley, S.A., Z.M. Summers, A.E. Franks, K.P. Nevin, D.R. Lovley. Microbial Electrosynthesis Optimization with Clostridia ljungdahlii. International Green Remediation Conference. 2010.
• Hensley, S.A., T.L. Woodard, A.E. Franks, K.P. Nevin, D.R. Lovley. Selection for Enhanced Current Production in Marine Fuel Cells. Microbiology Departmental Seminar. University of Massachusetts - Amherst. 2009.
• Hensley, S.A., T.L. Woodard, K.P. Nevin, D.R. Lovley. Selection/Adaptation of Marine Geobacteraceae with Superior Capabilities for Current Production. ASM. 2009.
• Hensley, S.A., C.H. Kyle, J. McDonough, R.L. Burks. Small snails grow up fast: Feeding preferences, habitat choice and growth of juvenile applesnails (Pomacea insularum) in the presence of Procambarus clarkii. Biology Departmental Seminar. Southwestern University. 2008.
• Hensley, S.A., C.H. Kyle, J. McDonough, R.L. Burks. Small snails grow up fast: Feeding preferences, habitat choice and growth of juvenile applesnails (Pomacea insularum) in the presence of Procambarus clarkii. Texas Academy of Sciences Meeting. 2008.
• S.A. Hensley. L. Shimkets. Genes present in the Fib A pathway of fruiting body formation in Myxococcus xanthus. Summer Undergraduate Research Poster Session. Microbiology Department. University of Georgia. 2007.

Community Outreach

• Graduate Affairs Coordinator. First Annual North American Bioelectric Systems Meeting. 2010.
• Laboratory Presenter and Guide for High School Education. 2009 - 2010.
• PBS. Exotic Invasive Species. 2008.

Awards

• Second Prize. Student Poster Competition. International Green Remediation Conference. 2010.
• Honorable Mention. Student Oral Presentation. Texas Academy of Sciences Meeting. 2008.