Graciela Lorca

Associate ProfessorLorca300

Department of Microbiology and Cell Science University of Florida

Ph.D. (2001) National University of Tucuman, Argentina.
Postdoctoral: (2004-2006) University of Toronto. Canada, (2001-2004) University of California San Diego (UCSD) USA.

Contact Information


Teaching Interests

Basic biology of microorganisms MCB-3023

Description of Research

General areas: transcriptional regulation, comparative genomics.

We are interested in the chemical biology of one-component transcriptional regulators (TF). They are involved in the regulation of the gene expression in response to a wide variety of intracellular and environmental signals. My lab is particularly interested in the identification of those small signal molecules using high throughput screening of small molecule libraries, and in how the small molecule/TF interactions can be modified/optimized. We are exploring the possibility of using new regulatory networks for the in vivo delivery of bioactive molecules using Lactobacillus as live vector.

Publications in Pub Med

Awards and Distinctions

  • Pew Latin American Fellowship in the Biomedical Sciences, USA (2001-2003).
  • Fellowship awarded by the National Center of Science and Technology (CONICET – Argentine) for the realization of the Ph. D. Thesis (1996-2001).

Selected Publications

Original papers
  1. Pande SG, Pagliai FA, Gardner CL, Wrench A, Narvel R , Gonzalez CF, Lorca GL. (2011) Lactobacillus brevis responds to flavonoids through KaeR, a LysR-type of transcriptional regulator. Mol. Microbiol. PMID: 21819457
  2. Kingma SD, Li N, Sun F, Valladares RB, Neu J, Lorca GL. (2011) Lactobacillus johnsonii N6.2 stimulates the innate immune response through Toll-like receptor 9 in Caco-2 cells and increases intestinal crypt Paneth cell number in biobreeding diabetes-prone rats. J Nutr.  Jun;141(6):1023-8. Epub 2011 Apr 13
  3. Lau K, Benitez P, Ardissone A, Wilson TD, Collins EL, Lorca G, Li N, Sankar D, Wasserfall C, Neu J, Atkinson MA, Shatz D, Triplett EW, Larkin J 3rd (2011) Inhibition of type 1 diabetes correlated to a Lactobacillus johnsonii N6.2-mediated Th17 bias. J Immunol. 2011 Mar 15;186(6):3538-46. Epub 2011 Feb 11
  4. Valladares R, Sankar D, Li N, Williams E, Lai KK, Abdelgeliel A, Gonzalez CF, Wasserfall C, Larkin 3rd J, Schatz D, Atkinson M, Triplett E, Neu J, Lorca, G.L. Lactobacillus johnsonii N6.2 mitigates the development of type 1 diabetes in BB-DP rats. Plos One May 6;5(5):e10507.
  5. Josef Neu,Graciela Lorca, Sandra Kingma and Eric W. Triplett. The Intestinal Microbiome: Relationship to Type 1 Diabetes Type I Diabetes, Endocrinology &Metabolism Clinics of North America, Volume 39, Issue 3,2010, Pages 563-571
  6. Pagliai FA, Gardner CL, Pande SG, Lorca, G.L. (2010) LVIS553 transcriptional regulator specifically recognizes novobiocin as an effector molecule. Journal of Biological Chemistry [Epub 2009 Dec 22.]
  7. McRae S, Pagliai, F.A., Mohapatra, N.P., Gener, A., Abdelgeliel Mahmou, A.S., Gunn, J.S., Lorca, G.L. and Gonzalez, C.F. (2010) Inhibition of AcpA phosphatase activity with ascorbate attenuates Francisella tularensis intramacrophage survival. J. Biol Chem. 285:5171-5177
  8. Lai KK, Lorca GL, Gonzalez CF (2009). Biochemical properties of two cinnamoyl esterases purified from a Lactobacillus johnsonii strain isolated from stool samples of diabetes-resistant rat. Appl Environ Microbiol. 2009 Aug;75(15):5018-24. Epub 2009 Jun 5.PMID: 19502437
  9. Teplitski M, Wright AC, Lorca G.(2009) Biological approaches for controlling shellfish-associated pathogens. Curr Opin Biotechnol. 2009 Apr;20(2):185-90. Epub 2009 Apr 1.
  10. Roesch LF, Lorca GL, Casella G, Giongo A, Naranjo A, Pionzio AM, Li N, Mai V, Wasserfall CH, Schatz D, Atkinson MA, Neu J, Triplett EW (2009). Culture-independent identification of gut bacteria correlated with the onset of diabetes in a rat model. ISME J. 2009 May;3(5):536-48. Epub 2009 Feb 19.
  11. Lorca, G.L., J.R. Walker, A. Ezersky, S. Altamentova, E. Evdokimova, M.Vedadi, V. Lunin, A. Bochkarev, and A. Savchenko. Identification of effector molecule for E. coli IclR transcriptional factor. Journal of Biological Chemistry. In Press.
  12. Lorca, G. L, R. D. Barabote, B. Winnen, R. N. Hvorup, V. Zlotopolski, E. Nguyen, L.W. Huang, C. Phan, and M. Saier, Jr. 2007.  Comparative analysis of the transport capabilities encoded within the genome of eleven gram-positive bacteria. BBA – Biochimica et Biophysica Acta In Press.
  13. Makarova, K., A. Slesarev, Y. Wolf, A. Sorokin, B. Mirkin, E. Koonin, A. Pavlov, N. Pavlova, V. Karamychev, N. Polouchine, V. Shakhova, I. Grigoriev, Y. Lou, D. Rohksar, S. Lucas, K. Huang, D. M. Goodstein, T. Hawkins, V. Plengvidhya, D. Welker, J. Hughes, Y. Goh, A. Benson, K. Baldwin, J.-H. Lee, I. Díaz-Muñiz, B. Dosti, V. Smeianov, W. Wechter, R. Barabote, G. Lorca, E. Altermann, R. Barrangou, B. Ganesan, Y. Xie, H. Rawsthorne, D. Tamir, C. Parker, F. Breidt, J. Broadbent, R. Hutkins, D. O’Sullivan, J. Steele, G. Unlu, M. Saier, T. Klaenhammer, P. Richardson, S. Kozyavkin, B. Weimer, and D. Mills. 2006. Comparative genomics of the lactic acid bacteria. Proceedings  of the National Academy of Sciences 103:15611-15616
  14. Walker, J. W., S. Altamentova, A. Ezersky, G. Lorca, T. Skarina, M. Kudritska, A. Bochkarev and A. Savchenko. 2006. Structural and biochemical analysis of transcriptional repression mechanism mediated by E. coli glyoxylate and allantoin utilization regulatory protein AllR. Journal of Molecular Biology 358:810-828.
  15. Lorca, G. L., Y. J. Chung, R. D. Barabote, W. Weyler, C. H. Schilling , and Milton H. Saier, Jr.2005. Catabolite repression/activation in Bacillus subtilis: dependency on CcpA, HPr and HprK. Journal of Bacteriology, 187:7826-7839.
  16. Gonzalez, C.F., A. Stonestrom, G.L. Lorca, and Saier Jr., M.H. 2005. Biochemical characterization of phosphoryl transfer involving Hpr of the phosphoenolpyruvate-dependent phosphotransferase system in Treponema denticola, an organism lacks PTS permeases. Biochemistry, 44:598-608.
  17. Lorca, G., B. Winnen, and M. Saier. 2003. Identification of the L-aspartate transporter in Bacillus subtilis. Journal of Bacteriology 185:3218-3222.
  18. Taranto M.P., M. L. Fernandez Murga, G. Lorca, G. F. de Valdez. 2003. Bile salts and cholesterol induce changes in the lipid cell membrane of Lactobacillus reuteri. Journal of Applied Microbiology 95: 86-91.
  19. Rollan, G., G. L. Lorca, and G. Font de Valdez. 2003. Arginine catabolism and acid tolerance response in Lactobacillus reuteri isolated from sourdough. Food Microbiology 20:313-319.
  20. Kruszewska D., J. Lan, G. Lorca, N. Yanagisawa , I. Marklinder and Å. Ljungh. 2002.  Selection of lactic acid bacteria as probiotic strains by in vitro tests. Microecology and Therapy 29:37-49.
  21. Lorca, G. L., G. Font de Valdez, and Å. Ljungh. 2002. Characterization of the protein-synthesis dependent adaptive acid tolerance response in Lactobacillus acidophilus. Journal of Molecular Microbiology and Biotechnology 4:525-532.
  22. Lorca, G. L., M. I. Torino, G. Font de Valdez, and Å. Ljungh. 2002. Lactobacilli express cell surface proteins which mediate binding of immobilized collagen and fibronectin. FEMS Microbiology Letters 206: 31-37.
  23. Lorca, G. L., T. Wädstrom, G. Font de Valdez, and Å. Ljungh. 2001. Lactobacillus acidophilus autolysins inhibit Helicobacter pylori In vitro.  Current Microbiology 42:39-44.
  24. Lorca, G. L., and G. Font de Valdez. 2001. A-low-pH-inducible stationary-phase acid tolerance response in Lactobacillus acidophilus CRL 639. Current Microbiology 42:21-25.
  25. Lorca, G. L., and G. Font de Valdez. 2001. Acid tolerance mediated by membrane ATPases in Lactobacillus acidophilus. Biotechnology Letters 23:777-780.
  26. Lorca, G. L. and G. Font de Valdez. 1999. Effect of suboptimal growth temperature and growth phase on resistance of Lactobacillus acidophilus to environmental stress. Cryobiology 39:144-149
  27. Lorca, G. L. and G. F. de Valdez. 1998. Temperature adaptation and cryotolerance in Lactobacillus acidophilus. Biotechnology Letters 20 (9): 847-849.
  28. Lorca, G. L., R. R. Raya, M. P. Taranto, and G. F. de Valdez. 1998. Adaptative acid tolerance response in Lactobacillus acidophilus. Biotechnology Letters 20 (3):239-241.
  29. Font de Valdez, G., G. Martos, M. P. Taranto, G. L. Lorca, G. Oliver, and A. P. de Ruiz Holgado. 1997. Influence of bile on Lactobacillus reuteri subjected to freeze-drying. Journal of Dairy Science 80:1955-1958.
Chapters in Books
  1. Font de Valdez, G. M., G. Lorca, and M. P. Taranto. 1999. Conductimetric method for evaluating inhibition of Listeria monocytogenes. Food Microbiology Protocols. Series Methods in Biotechnology. Humana Press Inc.
  2. Lorca, G. L. and G. M. Font de Valdez. 2007. Lactobacillus stress responses. In Lactobacillus Molecular Biology. Humana Press Inc. In Press
University publications
  1. Lorca, G. L. (1996) Graduate Thesis. Genetic aspects of the bile salt deconjugation by lactic acid bacteria. National University of Misiones (Argentine)
  2. Lorca G. L. (2001) Ph. D. Thesis. Survival strategies of Lactobacillus acidophilus under stress conditions. National University of Tucuman (Argentine)



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