Angert Lab Research Interests:

Epulopiscium spp. are the largest known heterotrophic bacteria.  Individual, cigar-shaped cells can reach lengths in excess of 600 µm; large enough to be seen with the naked eye.  In terms of cell volume, Epulopiscium can be as much as a million times larger than a bacterium the size of Escherichia coli.  Another unusual feature of these big bacteria is the manner in which they reproduce.  While most bacteria undergo binary fission -- growing to about twice their starting size and dividing into two equivalent daughter cells -- an Epulopiscium cell can produce multiple offspring intracellularly.  These internal offspring grow inside the mother cell until they completely fill the mother cell cytoplasm.  The offspring cells eventually burst through the mother cell envelope and are released.  Morphological and phylogenetic evidence suggests that this novel form of reproduction evolved from endospore formation.  The image below shows a particularly large Epulopiscium cell that contains two large offspring.

"Epulopiscium"  means  "guest at a banquet of a fish".  So named because Epulopiscium spp. (including Epulopiscium fishelsoni) live in the intestinal tract of certain species of tropical marine surgeonfish.  Based on genome sequence analyses, these intestinal symbionts aid the breakdown and digestion of algae consumed by their surgeonfish host.

Research in the Angert lab focuses on several aspects of Epulopiscium biology.

1. Characterizing cellular modifications that support large cell size.
2. Identifying molecular mechanisms involved in intracellular offspring formation and development. 
3. Determining how reproductive strategy impacts the symbiotic relationship of intestinal bacteria and their vertebrate host. 

We have developed a number of approaches to study Epulopiscium spp. and relatives in their natural environments.  Current research projects use comparative genomics, phylogenetics, cell biological and microbiological methods to study these exceptional microorganisms.  In addition, we have on-going collaborative projects describing the ecology and diversity of gastrointestinal microbial symbionts of fish and their impact on fish health and nutrition.

Courses:

BioMI 1120   Microbes, the Earth, and Everything

We live on a microbial earth.  This course showcases the vast microbial diversity all around us and uses examples, relevant to our everyday lives, to explore fundamental biological principles.  Course modules emphasize basic concepts including: evolution, molecular biology & genetics, diversity, and ecology.  We will learn about the tiny titans and miniature monsters that are the life support system of our planet, how they have shaped human civilizations, and how they reveal the unifying principles of life.

BioMI 3910   Advanced Microbiology Laboratory

An introduction to advanced experimental methods in microbiology.  In this course, students will gain experience with cutting-edge technologies used to characterize structural, physiological, and genetic aspects of microbes.  These skills will be applied during the isolation and characterization of bacteria from the environment.

BioMI 7910   Advanced Topics in Microbiology

a.k.a. The Microbiology Journal Club 

Readings, presentations and discussions by graduate students and faculty of current topics in microbiology research.

Biographical Sketch: 

Esther Angert earned a B.S. in Biology from Indiana University of Pennsylvania.  Her graduate training was in the laboratory of Dr. Norman Pace at Indiana University, Bloomington, IN, where she earned her Ph.D.  She was Jane Coffin Childs Postdoctoral Fellow with Dr. Richard Losick at Harvard University before joining the Cornell faculty in the Department of Microbiology in 1999.

Selected Publications:

Click here for a PubMed listing of Dr. Angert's publications

D. A. Miller, K. D. Clements, J. H. Choat and E. R. Angert.  2011.  The spoIIE homolog of Epulopiscium sp. type B is expressed early in intracellular offspring development.  Journal of Bacteriology 193: 2642-2646.

D. A. Miller et al.  2011.  The complete genome sequence of the cellulose-degrading bacterium Cellulosilyticum lentocellum.  Journal of Bacteriology 193: 2357-2358.

J. C. Frey, A. N. Pell, R. Berthiaume, H. Lapierre, S. Lee, J. K. Ha, J. E. Mendell and E. R. Angert.  Comparative studies of microbial populations in the rumen, duodenum, illeum and feces of lactating dairy cows.  2010.  Journal of Applied Microbiology  108: 1982-1993.

R. J. Ward, K. D. Clements, J. H. Choat and E. R. Angert.  2009.  Cytology of terminally differentiated Epulopiscium mother cells.  DNA and Cell Biology 28:  57-64.

J. E. Mendell, K. D. Clements, J. H. Choat and E. R. Angert.  2008.  Extreme polyploidy in a large bacterium.  Proceedings of the National Academy of Sciences USA 105:  6730-6734.

R. J. Ward and E. R. Angert.  2008.   DNA replication during endospore development in Metabacterium polyspora.  Molecular Microbiology 67:  1360-1370.

E. R. Angert. 2006.  The enigmatic cytoarchitecture of Epulopiscium spp.  In Microbiology Monographs, vol 2, Complex Intracellular Structures in Prokaryotes.  Ed. J. M. Shively.  Springer-Verlah, Berlin, pp. 285-301.

J. F. Flint, D. Drzymalski, W. L. Montgomery, G. Southam and E. R. Angert. 2005. Nocturnal production of endospores in natural populations of Epulopiscium-like surgeonfish symbionts. Journal of Bacteriology 187: 7460-7470. [pdf]

E. R. Angert. 2005. Alternatives to binary fission in bacteria. Nature Reviews Microbiology 3: 214-224. [pdf]

E. R. Angert and K. D. Clements. 2004. Initiation of intracellular offspring in Epulopiscium. Molecular Microbiology 51: 827-835. [pdf]

J. H. DeMera and E. R. Angert. 2004. Comparison of the antimicrobial activity of honey produced by Tetragonisca angustula (Meliponinae) and Apis mellifera L. from different phytogeographical regions of Costa Rica. Apidologie 35: 411-417. [pdf]

E. R. Angert and R. M. Losick. 1998. Propagation by sporulation in the guinea pig symbiont Metabacterium polyspora. Proceedings of the National Academy of Sciences USA 95: 10218-10223. [pdf]

C. Robinow and E. R. Angert. 1998. Nucleoids and coated vesicles of "Epulopiscium" spp. Archives of Microbiology 170: 227-235. [pdf]

E. R. Angert, D. E. Northup, A.-L. Reysenbach, A. S. Peek, B. M. Goebel and N. R. Pace. 1998. Molecular phylogenetic analysis of a bacterial community in Sulphur River, Parker Cave, Kentucky. American Minerologist 83: 1583-1592.

E. R. Angert, A. E. Brooks and N. R. Pace. 1996. Phylogenetic analysis of Metabacterium polyspora: Clues to the evolutionary origin of Epulopiscium spp., the largest bacteria. Journal of Bacteriology 178: 1451-1456. [pdf]

E. R. Angert, K. D. Clements and N. R. Pace. 1993. The largest bacterium. Nature 362: 239-241.