University of Minnesota
MICaB Graduate Program
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Current Students

Rebecca Breuer

Thesis Advisor: Gary Dunny

Year entered: 2013

Degrees received:
B.S., University of Wisconsin, Madison, WI, 2012

Honors and Awards:

  • 2014: Microbial and Plant Genomics Institute Travel Grant to the 2014 Molecular Genetics of Bacteria and Phages Meeting in Madison, WI
  • 2014- 2016: NIGMS BioTechnology Trainee
  • 2015- 2016: Biofilm Club Planning Committee
  • 2015: BioTechnology Exchange Student to NAIST in Ikoma, Nara, Japan
  • 2016: ASM Streptococcal Genetics Travel Grant
  • 2016: Microbial and Plant Genomics Institute Travel Grant to the 2016 ASM Conference on Streptococcal Genetics in Washington, D.C.
  • 2017: BTI travel grant to attend the ASM Cell-Cell Communications meeting

I study Enterococcus faecalis, a gram positive microbe that is normally a commensal organism in the human gastrointestinal tract but can also be an opportunistic pathogen. E. faecalis is particularly interesting due to its ability to grow in a biofilm, transfer genetic elements through conjugation, and assess its surroundings via quorum sensing. These features help E. faecalis evade antibiotics and rapidly transfer antibiotic resistance genes. In my thesis work under advisement of Gary Dunny and Wei-Shou Hu, I seek to better understand the mechanics of gene transfer and the process by which E. faecalis forms a robust biofilm matrix.  On the front of horizontal antibiotic resistance gene transfer, I am working to further understand the mechanisms surrounding conjugative transfer: intercellular communication, the pheromone response, and gene regulation on the single cell level. Astoundingly, although bacterial cells are clones and thus genetically identical, individual cells have varied responses to environmental conditions and signals required for conjugative transfer. In my thesis work I am working to determine how cells respond heterogeneously and how this variable behavior may impact bacterial fitness. With respect to biofilms, I am working to further elucidate how E. faecalis forms a productive biofilm through incorporation of extracellular DNA (eDNA) in the biofilm matrix. Toward these goals, I seek to characterize the eDNA and determine how it is released into the biofilm. 


  • L. S. Parreiras, R. J. Breuer, R. Avanasi Narasimhan, A. J. Higbee, A. La Reau, M. Tremaine, L. Qin, L. B. Willis, B. D. Bice, B. L. Bonfert, R. C. Pinhancos, A. J. Balloon, N. Uppugundla, T. Liu, C. Li, D. Tanjore, I. M. Ong, H. Li, E. L. Pohlmann, J. Serate, S. T. Withers, B. a Simmons, D. B. Hodge, M. S. Westphall, J. J. Coon, B. E. Dale, V. Balan, D. H. Keating, Y. Zhang, R. Landick, A. P. Gasch, and T. K. Sato, “Engineering and Two-Stage Evolution of a Lignocellulosic Hydrolysate-Tolerant Saccharomyces cerevisiae Strain for Anaerobic Fermentation of Xylose from AFEX Pretreated Corn Stover.,” PLoS One, vol. 9, no. 9, p. e107499, Jan. 2014.
  • T. K. Sato, T. Liu, L. S. Parreiras, D. L. Williams, D. J. Wohlbach, B. D. Bice, I. M. Ong, R. J. Breuer, L. Qin, D. Busalacchi, S. Deshpande, C. Daum, A. P. Gasch, and D. B. Hodge, “Harnessing genetic diversity in saccharomyces cerevisiae for fermentation of xylose in hydrolysates of alkaline hydrogen peroxide-pretreated biomass,” Appl. Environ. Microbiol., vol. 80, pp. 540–554, 2014.
  • T. K. Sato, M. Tremaine, L. S. Parreiras, A. S. Hebert, K. S. Myers, A. J. Higbee, M. Sardi S. J. McIlwain, I. M. Ong, R. J. Breuer, R. A. Narasimhan, M. A. McGee, Q. Dickinson, A. La Reau, D. Xie, M. Tian, J. L. Reed, Y. Zhang, J. J. Coon, C. T. Hittinger, A. P. Gasch, and R. Landick, “Directed evolution reveals unexpected epistatic interactions that alter metabolic regulation and enable anaerobic xylose use by Saccharomyces cervisiae.,PLOS Genetics, DOI: 10.1371/journal.pgen.1006372, Oct. 2016.
  • T. N. T. Tran*, R. J. Breuer*, R. A. Narasimhan, L. S. Parreiras, Y. Zhang, T. K. Sato, and T. P. Durrett, “Metabolic engineering of Saccharomyces cerevisiae to produce a reduced viscosity oil from lignocellulose.,” Biotechnology for Biofuels, DOI: 10.1186/s13068-017-0751-y, 2017.
  •  R. J. Breuer*, A Bandyopadhayay*, S. O’Brien, A. M. T. Barnes, R. Hunter, W. Hu, G.Dunny, “Stochasticity in the enterococcal sex pheromone response revealed by quantitative analysis of transcription in single cells,” PLOS Genetics, DO10.1371/journal.pgen.1006878, July 2017.