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 and NSF-0919682, in collaboration with George Luther, CEOE)

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 is the current focus including thiosulfate, elemental sulfur, sulfite and sulfide. A strong emphasis in this project is the development and application of improved techniques for the  molecular genetic analysis and manipulation of  C. tepidum.  The latest project will apply tools of electrochemical analysis to C. tepidum wild type and mutant strains in conjunction with proteomic and transcriptomic analyses to develop a better understanding of the response of this organism to a wide range of sulfide concentrations.

Metabolism and Ecology of Epsilonproteobacteria (in collaboration with Barb Campbell, CEOE and Martin Klotz, University of Louisville)

This project seeks to understand the distribution of Epsilonproteobacteria in terrestrial and marine environments coupled with detailed analysis of the model organism Nautilia profundicola strain AmH.  The genome sequence of strain AmH suggested that it must utilize a novel pathway for nitrate reduction and assimilation.  The physiology and regulation of this process is currently an active project between the Campbell, Hanson, and Klotz laboratories.

Arctic Sediment Metagenome Sequencing (supported by the DOE-JGI Community Sequencing Program, in collaboration with Dave Kirchman and Matt Cottrell, CEOE)

Methane is a major greenhouse gas and Arctic Ocean sediments contain large concentrations of methane clathrates, methane trapped in water ice "cages".  The DOE-JGI is collecting metagenomic sequences from sediment samples.  These sequences will be analyzed to determine how the microbial community structure of these sediments may differ relative to other marine sediment communities with a specific emphasis on both aerobic and anaerobic methane oxidation pathways.

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

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. High throughput sequencing coupled with functional assays of the moist acidic tundra microbial community revealed both structural and functional changes as a result of long term fertilization.  As part of my sabbatical in Fall 2010, I developed a culture collection from these soils that captured major groups as assessed by DGGE profiling.  This project is currently unfunded.

Phototrophic Bacterial Metabolism

Brian Eddie, Ph. D. student, Marine Biosciences  Email

Kevin Shuman, Ph. D. student, Biological Sciences  Email

Dan Hess, Ph. D. student, Biochemistry/Chemistry Biology Interface Program  Email

Amalie Tuerk, Ph. D. student, NSF Pre-doctoral fellow, Chemical Engineering, advised by Kelvin Lee  Email

Epsilonproteobacterial Ecology/Metabolism

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

Katie Kalis, M.S. student, Marine Biosciences  Email

Current Undergraduates

Juliana Letterie - research assistant

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

MAST 482 - Introduction to Ocean Sciences - Fall Semester, every year
MAST 625 - Microbial Physiology and Diversity - Spring Semester, odd numbered years
MAST XXX - Systems Biology I - Spring Semester, every year (permanent number coming soon)

For my publications in PubMed, click here.  For UDaily articles, click here.

Latest:

Eddie BJ, Hanson TE. Chlorobaculum tepidum TLS displays a complex transcriptional response to sulfide addition. J Bacteriol 195, 399-408

2012:

Kirchman DL, Hanson TE. Bioenergetics of photoheterotrophic bacteria in the oceans. Environ Microbiol Reports. doi: 10.1111/j.1758-2229.2012.00367.x

Bahrou AS, Ollivier PR, Hanson TE, Tessier E, Amouroux D, Church TM. Volatile
dimethyl polonium produced by aerobic marine microorganisms. Environ Sci Technol 46, 11402-11407

2011:

Have a look at the Frontiers in Microbiology Research Topic on the Microbial Sulfur Cycle that I helped put together with Martin Klotz and Don Bryant.

Krepski ST, Hanson TE, Chan CS. Isolation and characterization of a novel biomineral stalk-forming iron-oxidizing bacterium from a circumneutral groundwater seep. Environ Microbiol 14, 1671-1680

Rossmassler K, Engel AS, Twing KI, Hanson TE, Campbell BJ. Drivers of Epsilonproteobacterial community composition in sulfidic caves and springs. FEMS Microbiol Ecol 79, 421-432

Ollivier  PRL, Bahrou AS, Church TM, Hanson TE. Aeration controls the reduction and methylation of tellurium by the aerobic tellurite resistant marine yeast Rhodotorula mucilaginosa. Appl Environ Microbiol 77, 4610-4617

Rodriguez J, Hiras J, Hanson TE. Sulfite oxidation in Chlorobaculum tepidum. Front Microbio 2, 112 doi: 10.3389/fmicb.2011.00112

Luther GW, Findlay AJ, MacDonald DJ, Owings SM, Hanson TE, Beinart RE, Girguis PR. Thermodynamics and kinetics of sulfide oxidation by oxygen: a look at inorganically controlled reactions and biologically mediated processes in the environment. Front Microbio 2, 62 doi: 10.3389/fmicb.2011.00062

2010:

Wenter R, Hütz K, Dibbern D, Li T, Reisinger V, Plöscher M, Eichacker L, Eddie B, Hanson T, Bryant DA, Overmann J. Expression based identification of genetic determinants of the bacterial symbiosis 'Chlorochromatium aggregatum'. Environ Microbiol 12, 2259-2276

Hanson TE, Morgan-Kiss RM, Chan LK, Hiras J. Beyond the genome: functional studies of phototrophic sulfur oxidation. Adv Exp Med Biol 675, 109-121

Campbell BJ, Polson SW, Hanson TE, Mack MC, & Schuur EAG. The effect of nutrient deposition on bacterial communities in Arctic tundra soil. Environ Microbiol 12, 1842-1854

2009:

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 Physiol 151, 2145-2151.                      The paper is here and the UDaily article is here.

Campbell BJ, Smith JL, Hanson TE, Klotz MG, Stein LY, et al. 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. 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. Chlorobaculum tepidum regulates chlorosome structure and function in response to temperature and electron donor availability. Photosynth Res 99, 11-21

Postdoctoral:

Dr. Patrick Ollivier, Postdoctoral in France.

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

Dr. Lisa Waidner

Graduate:

Jennifer Hiras, Ph.D., Marine Biosciences. Jen is now a postdoc at the DOE Joint Bioenergy Institute in the Microbial Communities group within the Deconstruction Division.  She can be reached here.

Leong-Keat Chan, Ph.D., Marine Biosciences.  LK was a Postdoc with Mary Ann Moran at the University of Georgia and has recently moved to work with Rex Malmstrom at the DOE Joint Genome Institute.

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 in private practice in California.

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, DVM from University of Georgia, College of Veterinary Medicine now in private practice in Delaware

Glenn Christman, B.S. in Biochemistry, M.S. graduate from 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

James Pittman, B.S. in Environmental Science

Emily Alff, B.S. in Environmental Science, M.S. in Plant and Soil Science with Harsh Bais at UD.  Now employed at NovaFlora

Laura Treible, B.S. in Environmental Science, Sea Grant Scholar, NY Sea Grant

Jesse Rodriguez, Post-Baccalaureate Research Education Program, UPenn

Shannon Owings, undergraduate researcher at UD with George Luther

Delaware Environmental Institute

Center for Environmental Genomics

Center for Bioinformatics and Computational Biology

Chemistry-Biology Interface Program