C. S. is a fellow of CONICET (Argentina), and V. B. and C. M. are Career Investigators from CONICET (Argentina). References 1. Hugenholtz J: Citrate metabolism in lactic acid bacteria. FEMS Microbiol Rev

MI-503 chemical structure 1993, 12:165–178.CrossRef 2. Giraffa G: Enterococci from foods. FEMS Microbiol Rev 2002,26(2):163–171.PubMedCrossRef 3. Mills D, Rawsthorne H, Parker C, Tamir D, Makarova K: Genomic analysis of Oenococcus oeni PSU-1 and its relevance to winemaking. FEMS Microbiol Rev 2005,29(3):465–475.PubMed 4. Martin MG, Magni C, de Mendoza D, Lopez P: CitI, a Transcription Factor Involved in Regulation of Citrate Metabolism in Lactic Acid Bacteria. J Bacteriol 2005,187(15):5146–5155.PubMedCrossRef 5. Martin MG, Sender PD, Peiru S, de Mendoza D, Magni C: Acid-Inducible Transcription of the Operon Encoding the Citrate Lyase Complex of Lactococcus lactis Biovar diacetylactis CRL264. J Bacteriol 2004,186(17):5649–5660.PubMedCrossRef 6. Blancato VS, Repizo GD, Suarez CA, Magni C: Transcriptional Regulation of the Citrate Gene Cluster of Enterococcus faecalis Involves the GntR Family Transcriptional Activator CitO. J Bacteriol 2008,190(22):7419–7430.PubMedCrossRef 7. Sobczak I, Lolkema JS: The 2-Hydroxycarboxylate Transporter Family: Physiology, Structure, and Mechanism. Microbiol Mol Biol Rev 2005,69(4):665–695.PubMedCrossRef 8. Martin M, Corrales

M, de Mendoza D, Lopez Nutlin-3 molecular weight P, Magni C: Cloning and molecular characterization of the citrate utilization citMCDEFGRP cluster of Leuconostoc paramesenteroides. MTMR9 FEMS Microbiol Lett 1999,174(2):231–238.PubMedCrossRef 9. Blancato V, Magni C, Lolkema J: Functional characterization and Me ion specificity of a Ca-citrate transporter from

Enterococcus faecalis. FEBS J 2006,273(22):5121–5130.PubMedCrossRef 10. Espariz M, Repizo G, Blancato V, Mortera P, Alarcon S, Magni C: Identification of Malic and Soluble Oxaloacetate Decarboxylase Enzymes in Enterococcus faecalis. FEBS J 2011. 11. Sender P, Martin M, Peiru S, Magni C: Characterization of an oxaloacetate decarboxylase that belongs to the malic enzyme family. FEBS Lett 2004,570(1–3):217–222.PubMedCrossRef 12. Martin M, Magni C, Lopez P, de Mendoza D: Transcriptional Control of the Citrate-Inducible citMCDEFGRP Operon, Encoding Genes Involved in Citrate Fermentation in Leuconostoc paramesenteroides. J Bacteriol 2000,182(14):3904–3912.PubMedCrossRef 13. Foulquie Moreno M, Sarantinopoulos P, Tsakalidou E, De Vuyst L: The role and application of enterococci in food and health. Int J Food Microbiol 2006,106(1):1–24.PubMedCrossRef 14. Sarantinopoulos P, Kalantzopoulos G, Tsakalidou E: Citrate Metabolism by Enterococcus faecalis FAIR-E 229. Appl Envir Microbiol 2001,67(12):5482–5487.CrossRef 15. Rea M, Cogan T: Glucose prevents citrate metabolism by enterococci. Int J Food Microbiol 2003,88(2–3):201–206.PubMedCrossRef 16.