People | Thomas E. Hanson

• B.S., Bacteriology, University of Wisconsin, 1992.
• Ph.D., Microbiology, University of California, 1998.

My research program is focused on identifying and understanding the physiological strategies and adaptations that allow microorganisms to survive and compete in the environment. Our understanding of real world microbial physiology is currently limited. While microorganisms constitute a significant amount of the biomass and biodiversity on earth, only a small fraction of all the microorganisms in nature have been cultured. Furthermore, genome sequences of cultured microorganisms reveal that 32-75% of predicted genes encode proteins of unknown function. Presumably these genes are present in particular organisms because they confer the ability to effectively compete for specific ecological niches in the environments where the organisms live. These observations suggest that microorganisms contain a wealth of undiscovered physiological and genetic potential and that we do not fully understand what genetic complement is required for success in situ.

Phototrophic Bacterial Metabolism (supported by NSF-0447649)

This project is focused on dissecting the roles of specific genes in shaping the metabolism of the phototrophic bacterium Chlorobium tepidum. The oxidation of reduced sulfur compounds as energy sources and the physiological role of an unusual RubisCO-like protein are the current areas of interest. A strong emphasis in this project is the development and application of improved techniques for the genetic manipulation of  C. tepidum.

Microbial Metalloid Metabolism (supported by NSF-0425199, in collaboration with Tom Church, CEOE)

This project studies the formation of volatile polonium (Po) and tellurium (Te) species in marine environments. These two elements may provide a metric of air-sea metalloid evasion using the natural radionuclide 210Po by comparison to its stable Group XVI congener Te. The basic chemical properties of polonium and tellurium suggest that alkylation will occur via common reactions, and strong field evidence exists for the production of volatile species of both elements in marine environments. The central hypothesis is that stable alkyl species of polonium and tellurium contribute to their volatile flux across the marine atmospheric boundary. My group contributes microbial expertise to the project to supply biologically produced alkyl-metalloid compounds and to identify marine microbes that may synthesize these compounds in situ.

Tundra Soil Microbes and Ecosystem Ecology (in collaboration with Barb Campbell, CEOE, Michelle Mack and Ted Schuur, University of Florida)

Climate change models suggest that major shifts in carbon storage may occur, especially in northern latitudes where greater than 1/3 of the earth's carbon pool is stored. This project seeks to understand how microbial communities in Arctic tundra soils are changed by long (> 20 years) and short (< 1 year) term manipulation of nutrients and temperature at the Toolik Lake, AK, long term ecological research station. Microbial community structure and function likely play critical roles in determining carbon storage vs. release in tundra soils. Use of a novel molecular method combined with standard microbial physiological profiling will provide an unprecedented level of detail about tundra soil microbial community structure and function. Understanding how changes in climatic forcing factors affect microbial populations will refine predictions of carbon dynamics relative to existing trends in global change. Changes found in this study may also reflect past climate change events, allowing improved characterization of the geological record. This proposal will ground truth an emerging molecular technique for application in microbial ecology and generate supporting material for future studies in microbial responses to climate change.

Click here to see a poster summarizing current research projects.
(After opening, left click, wait for orange button, click button to zoom)

Phototrophic Bacterial Metabolism

Jennifer Hiras, Ph.D. Student, Marine Biosciences
Email: jhiras@udel.edu

Ernest Bonsu, Ph. D. student, Biological Sciences                                                              Email: ern@udel.edu

Brian Eddie, Ph. D. student, Marine Biosciences                                                                 Email: beddie@udel.edu

Epsilonproteobacterial Ecology

Karen Rossmassler, Ph. D. student, Marine Biosciences (Advisor: Barb Campbell)             Email: karenr@udel.edu

Current Undergraduates

Emily Alff - Research Intern

Jesse Rodriguez - BISC468

Looking for undergraduate researchers: e-mail tehanson@udel.edu if interested!

MAST 482 - Introduction to Ocean Sciences - Fall Semester, every year
MAST 827 - Microbial Physiology and Diversity - Spring Semester, odd numbered years
CHEM 667 - Evironmental Chemistry - Spring Semester, odd numbered years

For my publications in PubMed, click here.

Latest:

Bains G, Sampath Kumar A, Rudrappa T, Alff E, Hanson TE, & Bais HP. Native plant and microbial contributions to a negative plant-plant interaction.  Plant Physiology.  In press.

2009:

Campbell BJ, Smith JL, Hanson TE, Klotz MG, Stein LY, et al. (2009) Adaptations to Submarine Hydrothermal Environments Exemplified by the Genome of Nautilia profundicola. PLoS Genet 5, e1000362  The paper is here, the UDaily article on the paper is here, the NSF press release is here.

Chan, L. K., Morgan-Kiss, R. M., & Hanson, T. E. (2009). Functional analysis of three sulfide:quinone oxidoreductase homologs in Chlorobaculum tepidum. J Bacteriol 191, 1026-1034

Morgan-Kiss, R. M., Chan, L. K., Weber, T. S. & Hanson, T. E. (2009). Chlorobaculum tepidum regulates chlorosome structure and function in response to temperature and electron donor availability. Photosynth Res 99, 11-21.

2008:

Ollivier, P. R. L., Bahrou, A. S., Marcus, S., Cox, T., Church, T. M. & Hanson, T. E. (2008). Volatilization and precipitation of tellurium by aerobic, tellurite resistant marine microbes. Appl Environ Microbiol 74, 7163-7173. 

Our paper supplied the cover art for this issue.  Thanks to Shannon Modla of the BioImaging Center for making such a cool image!

Chan, L. K., Weber, T. S., Morgan-Kiss, R. M. & Hanson, T. E. (2008). A genomic region required for phototrophic thiosulfate oxidation in the green sulfur bacterium Chlorobium tepidum (syn. Chlorobaculum tepidum). Microbiology 154, 818-829.

Morgan-Kiss, R. M., Ivanov, A. G., Modla, S., Czymmek, K., Huner, N. P., Priscu, J. C., Lisle, J. T. & Hanson, T. E. (2008). Identity and physiology of a new psychrophilic eukaryotic green alga, Chlorella sp., strain BI, isolated from a transitory pond near Bratina Island, Antarctica. Extremophiles 12, 701-711.

Tabita, F. R., Satagopan, S., Hanson, T. E., Kreel, N. E. & Scott, S. S. (2008). Distinct form I, II, III, and IV Rubisco proteins from the three kingdoms of life provide clues about Rubisco evolution and structure/function relationships. J Exp Bot 59, 1515-1524.

Tabita, F. R., Hanson, T. E., Satagopan, S., Witte, B. H. & Kreel, N. E. (2008). Phylogenetic and evolutionary relationships of RubisCO and the RubisCO-like proteins and the functional lessons provided by diverse molecular forms. Philos Trans R Soc Lond B Biol Sci 363, 2629-2640.

Smith, J. L., Campbell, B. J., Hanson, T. E., Zhang, C. L. & Cary, S. C. (2008). Nautilia profundicola sp. nov., a thermophilic, sulfur-reducing epsilonproteobacterium from deep-sea hydrothermal vents. Int J Syst Evol Microbiol 58, 1598-1602.

Chan, L. K., Morgan-Kiss, R. & Hanson, T. E. (2008). Genetic and proteomic studies of sulfur oxidation in Chlorobium tepidum (syn. Chlorobaculum tepidum). In Sulfur in Phototrophic Organisms, pp. 363-379. Edited by R. Hell, C. Dahl, T. Leustek & D. Knaff. New York, N.Y.: Springer.

Wommack, K. E., Bench, S. R., Bhavsar, J., Mead, D., and T. Hanson. (2008) Isolation independent methods of characterizing phage communities 2: characterizing a metagenome. pp. 279-289 In: Bacteriophages: Methods and Protocols, Volume 2 Molecular and Applied Aspects (Clokie, M. R. J. & A. M. Kropinski eds.)

2007:

Bench, S. R., Hanson, T. E., Williamson, K. E., Ghosh, D., Radosevich, M., Wang, K. & Wommack, K. E. (2007). Metagenomic characterization of Chesapeake Bay virioplankton. Appl Environ Microbiol 73, 7629-7641.

Bidle, K. A., Hanson, T. E., Howell, K. & Nannen, J. (2007). HMG-CoA reductase is regulated by salinity at the level of transcription in Haloferax volcanii. Extremophiles 11, 49-55.

Chan, L. K., Morgan-Kiss, R. & Hanson, T. E. (2007). Sulfur oxidation in Chlorobium tepidum (syn. Chlorobaculum tepidum): genetic and proteomic analyses. In Microbial Sulfur Metabolism, pp. 117-126. Edited by C. Dahl & C. G. Friedrich. New York, N.Y.: Springer.

Tabita, F. R., Hanson, T. E., Li, H., Satagopan, S., Singh, J. & Chan, S. (2007). Function, structure, and evolution of the RubisCO-like proteins and their RubisCO homologs. Microbiol Mol Biol Rev 71, 576-599.

Zhou, F., Hanson, T. E. &

Postdoctoral:

Dr. Patrick Ollivier, Postdoctoral in France.

Dr. Rachael M. Morgan-Kiss, Assistant Professor, Department of Microbiology, Miami University

Dr. Lisa Waidner, Postdoctoral Researcher, Animal and Food Sciences and DBI, University of Delaware

Graduate:

Leong-Keat Chan, Ph.D., Marine Biosciences.  LK is currently a Postdoc with Mary Ann Moran at the University of Georgia. 

Andrew Bahrou, M.S., Oceanography.  Andrew has started a position with the State of Michigan. 

Undergraduate:

Joy Lawani, Validation Specialist, Bio-Pharm Division, BE&K Inc, www.bek.com

Steve Fatula, B.A. in Environmental Studies, Wesley College, graduate of Rutgers University-Camden in Environmental Law and Business.  Now working on passing the Bar Exam.

Nolberto Figueroa Matias, B.S. in Industrial Biotechnology, University of Puerto Rico-Mayaguez, M. S. in Chemical Engineering, University of Puerto Rico-Mayaguez.

Talisha Cox, B.A. in Biology, Lincoln University, Master's student in Environmental Science & Management at Duquesne University

Jessica Martin, B.S. in Animal Science, Vet Student, University of Georgia, College of Veterinary Medicine

Glenn Christman, B.S. in Biochemistry, M.S. student in Dave Kirchman's group

Egle Burbaite,  B.S. in Biological Sciences, Clinical Research Associate, ICON Clinical Research Inc.

Tim Weber, B.S. in Mechanical Engineering, Design Engineer at Streamlight

Michelle Madorma, B.S. in Animal Science, M.A. student in Ag & Tech Education at UD

Yun-Fei Lou, B. A. in Biological Sciences, Technician for Dave Hutchins at USC

Center for Critical Zone Research

Center for Environmental Genomics

Center for Bioinformatics and Computational Biology

September 2009:

It's official! Tom is promoted to Associate Professor with Tenure and gets to start using the new title this month.

August 2009:

Brian, Ernest, and Tom attended the International Symposium on Phototrophic Prokaryotes in Montreal, Canada.  Brian & Ernest gave posters, Tom gave a talk and captained the U.S. team to victory in the street hockey competition.  Brian says he took blackmail photos.

Ernest was selected to attend the FASEB-MARC Leadership Development/Grant Writing Seminar in Virginia Beach.