People | Barbara J. Campbell

• Ph.D., Microbiology, Cornell University, 1993.

My interests are centered on the function and structure of microbial communities at the molecular level.

A) Coastal and Open Ocean Microbial Community Dynamics

I have teamed up with David Kirchman and John Heidelberg (USC) to understand bacterial processes in the Sargasso Sea and Mid Atlantic Bight using molecular measures of bacterial activity. In these NSF projects, we are investigating the types and quantities of active bacteria and autotrophic and net heterotrophic seasons. We are using a combination of high-throughput tag sequencing and quantitative PCR of both ribosomal RNA and ribosomal RNA genes along with metatranscriptomics and single cell uptake assays to distinguish active bacteria from inactive bacteria. Characterizing who is active and what they are doing will greatly add to our understanding of the contribution of microbes to biogeochemical cycling in the oceans.

B) Epsilonproteobacteria from Terrestrial Springs and Caves

Annette Engel and I are coPIs on an NSF-funded project to study the systemactics of a group of environmentally important bacteria, the Epsilonproteobacteria. This group is responsible for the cycling of carbon, nitrogen and sulfur in many aphotic, sulfidic springs and caves. In many cases they are the dominant organisms found, suggesting that they are keystone species, and responsible for the bulk of the primary production that occurs. Please see Dr. Annette Engel's website for further information (http://www.geol.lsu.edu/Faculty/Engel/epsilon.htm).  We are currently in our second year of a three year project. My graduate student is currently developing PCR based assays specific for Epsilonproteobacteria and optiminzing single cell amplification techniques in order to assess the taxonomy of geographically distinct Epsilonproteobacteria that are nearly identical at the 16S rRNA gene level.

C) Hydrothermal Vent Bacterial Genomics/Metagenomics

I am currently involved in several projects involving understanding the metabolic potential of mixed microbial communities at deep-sea hydrothermal vents.  One of my current projects takes a metagenomics approach to understand the relationship of a mixed episymbiont community associated with the hydrothermal vent annelid, Alvinella pompejana. 

A second project involves characterizing the genome of a thermophilic Epsilonproteobacteria from deep-sea hydrothermal vents.  Microorganisms that thrive in these extreme environments must adapt to rapid fluctuations in temperature and chemistry, ranging from the  hot, sulfide- and heavy metal-laden plume at the vents' outlets to cold seawater in the surrounding region. I lead a team of investigators to sequence and characterize this bacterium, Nautilia profundicola. We found that its small genome has a versatile metabolic makeup. This slightly thermophilic organism (its optimum temperature is 45°C) contains a reverse gyrase gene, previously considered a hallmark of hyperthermophiles. We found that transcription is upregulated over 1000 fold in cells at 65°C.  The bacterium has several DNA repair genes not found in non-vent Epsilonproteobacteria that may be important in both thermal protection and radiation resistance. In addition, the genome contains six hydrogenases, several ATPases and other genes to obtain energy and reducing equivalents, suggesting a flexible metabolic strategy to deal with the fluctuating redox conditions at vents. It also uses a novel strategy for growth with nitrate as an N source. I am currently working with Tom Hanson and Martin Klotz (University of Louisville) to obtain experimental evidence for this novel pathway, including both growth under different physiological coniditions and gene expression analyses of key genes in the pathway.

D) Detection of Pathogenic-like Epsilonproteobacteria from Delaware's Coastal Waters

I just finished a two year NOAA Sea Grant project to test local marine and Inland Bay waters for the presence of pathogenic and pathogen-like Epsilonproteobacteria. Pathogenic members of this group include Helicobacter pylori and Campylobacter jejuni. These pathogens are associated with human gastric disease and gastroenteritis. We are working with resource managers from the Delaware Department of Natural Resources (DNREC) and Ed Whereat (Citizen's Monitoring Program for the Inland Bays) in correlating our results to standard methods of indicators of fecal contamination. 

Karen Rossmassler, B.S., University of California, San Diego, 2007 (Ph.D. student)

Sharon Grim, B.S., Bryn Mawr College, 2007 (M.S. student) 

Former Students

Katrina Twing, B.S., Clark College, 2007 (M.S. 2009) Katrina is starting a position in Andreas Teske's lab at the University of North Carolina, Chapel Hill.

Biocomplexity -Metagenomics Collaborators

Craig Cary (University of Delaware), Alison Murray (Desert Research Institute), Guang Gao (University of Delaware), Robert Feldman (Symbio Corporation), Mihailo Kaplarevic (University of Delaware), George Luther (University of Delaware), Joseph Grzymski (Desert Research Institute)

Microbial Genome Sequencing Collaborators:

Craig Cary (University of Delaware), Jonathan Eisen (The Institute for Genome Research), David Mead (Lucigen Corporation)

Other Collaborators that I work with Characterizing the Ubiquitous Epsilonproteobacteria

Annette Summers Engel, (Louisiana State University), Ken Takai, Subground AnimalculeRetrieval (SUGAR) Program, Extremobiosphere Research Center, Japan Agency for Marine-Earth Science & Technology, 2-15 Natsushima-cho, Yokosuka 237-0061, Japan

Campbell BJ, Yu LY, Straza TR, Kirchman DL. Temporal changes in bacterial rRNA and rRNA genes in Delaware (USA) coastal waters. Aquatic Microbial Ecology 2009, 57: 123-135

Lami R, Cottrell MT, Campbell BJ, Kirchman DL.  Light-dependent growth and proteorhodopsin expression by Flavobacteria and SAR11 in experiments with Delaware coastal waters. Environmental Microbiology 2009, doi:10.1111/j.1462-2920.2009.02028.x (online early)

Campbell BJ, Smith JL, Hanson TE, Klotz MG, Stein LY, Lee CK, Wu D, Robinson JM, Khouri HM, Eisen JA, Cary SC. Adaptations to submarine hydrothermal environments exemplified by the genome of Nautilia profundicola. PLoS Genetics 5: e1000362

Grzymski JJ, Murray AE, Campbell BJ, Kaplarevic M, Gao GR, Lee C, Daniel R, Ghadiri A, Feldman RA, Cary SC. Metagenomic analysis of an extreme microbial symbiosis reveals eurythermal adaptation and metabolic flexibility.  Proc Natl Acad Sci USA 2008, 105: 17516-17521

Smith JL, Cambpell BJ, Hanson TE, Zhang CL, Cary SC. Nautilia profundicola sp. nov., a thermophilic sulfur-reducing epsilonproteobacterium from deep-sea hydrothermal vents. Intl J Syst Evol Microbiol 2008, 58: 1598-1602

Cambpell BJ, Waidner LA, Cottrell MT, Kirchman DL. Abundant proteorhodopsin genes in the North Atlantic Ocean. Environ Microbiol 2008, 10: 99-109

Campbell BJ, Summers AE, Porter ML, Takai K. The versatile ε-proteobacteria: Key players in sulfidic environments. Nature Reviews Microbiology 2006, 4: 458-468

Takai K, Campbell BJ, Cary SC, Suzuki M, Oida H, Nunoura T, Hirayama H, Nakagawa S, Suzuki Y, Inagaki F, Horikoshi K. Enzymatic and genetic characterization of carbon and energy metabolisms by deep-sea hydrothermal chemolithoautotrophic isolates of Epsilonproteobacteria. Appl. Environ. Microbiol 2005, 71 (11): 7310-7320

Campbell, BJ, Cary, SC. Abundance of reverse tricarboxylic acid cycle genes in free-living microorganisms at deep-sea hydrothermal vents. Appl Environ Microbiol 2004, 70: 6282-6289

Cary SC, Campbell BJ, Delong EF. Studying the deep subsurface biosphere: emerging technologies and applications. In: The Subseafloor Biosphere at Mid-Ocean Ridges. Ed. W.S.D. Wilcock, D.S. Kelley, E.F. DeLong, J.A. Baross, S.C. Cary. Geophysical Monograph Series 2004, 144: 383-399

Campbell BJ, Stein JL, Cary SC. Evidence of chimolithoautotrophy in the bacterial community associated with Alvinella pompejana, a hydrothermal polychaete. Appl Environ Microbiol 2003, 69: 5070-5078

Campbell BJ, Cary SC. Characterization of a novel spirochete associated with the hydrothermal vent polychaete annelid, Alvinella pompejana. Appl Environ Microbiol 2001, 67: 110-117

Campbell BJ, Jeanthon C, Kostka JE, Luther GWIII, Cary SC. Growth and phylogentic properties of novel bacteria belonging to the subdivision of the Proteobacteria enriched from Alvinella pompejana and deep-sea hydrothermal vents. Appl Environ Microbiol 2001, 67: 4566-4572

Hutchins DA, Campbell BJ, Cottrell MT, Takeda S. Response of marine bacterial community composition to iron additions in three iron-limited regimes. Limnol Oceanog 2001, 46: 1535-1545

Slobodkin A, Campbell B, Cary SC, Bonch-Osmolovskaya E, Jeanthon C. Evidence for the presence of thermophilic Fe(III)-reducing microorganisms in deep-sea hydrothermal vents at 13°N (East Pacific Rise) FEMS. Microbiol Ecol 2001, 2-3: 235-243

Web Page for Metagenomics project:

Biocomplexity: A Meta-Genome Level of Analysis of an Extreme Microbial Symbiosis

Internal Web page for this project: http://ocean.dbi.udel.edu/index.php

Research Expedition web page:

http://www.ceoe.udel.edu/expeditions/index.html

Web page for Microbial Genome Sequencing project:

https://www.fastlane.nsf.gov/servlet/showaward?award=0333203