Genetics of Lactic Acid Bacteria

Summary

There is a demand in the population for high quality food, with high nutritional value, good sensorial characteristics, and lacking toxic components or potentially dangerous for health. Lactic acid bacteria constitute the main group of microorganisms in the production of fermented food. The survival of these microorganisms, which are continuously subjected to acid stress, constitutes an important line of research for the selection of LAB strains destined to food production.

Research Lines

Genetics of Lactic Acid Bacteria

There is a demand in the population for high quality food, with high nutritional value, good sensorial characteristics, and lacking toxic components or potentially dangerous for health. Lactic acid bacteria constitute the main group of microorganisms in the production of fermented food. The survival of these microorganisms, which are continuously subjected to acid stress, constitutes an important line of research for the selection of LAB strains destined to food production. One of the mechanisms of resistance to acid stress are decarboxylation reactions. These systems are formed by a membrane transporter, which allows the entry of the substrate, and a specific decarboxylase. Decarboxylation of organic acids (malate or citrate) and amino acids have been associated with mechanisms of resistance to acid stress in LB. The pathway of citrate fermentation is particularly important in the development of the aroma and texture of certain types of cheese, and also contributes to the aroma of wine. One of the products of this fermentation, diacetyl, is the main natural aroma compound. The general objective of our studies is to gain insight into the gene expression regulatory mechanisms of this important group of bacteria. In aspect related to beneficial and prejudicial features that result from the decarboxylation of certain metabolites in food production. Our research group has experience in studies of gene expression regulatory mechanisms, which still remain unknown for this group of bacteria. The acquired knowledge will allow us to understand in which conditions the decarboxylations are produced and to develop new production strategies for high quality food.

Selected Publications

  • Martino, G.P., Perez, C.E., Magni, C., Blancato, V.S. Implications of the expression of Enterococcus faecalis citrate fermentation genes during infection (2018) PLoS ONE, 13 (10), art. no. e0205787. DOI: 10.1371/journal.pone.0205787
  • Torres Manno, M., Zuljan, F., Alarcón, S., Esteban, L., Blancato, V., Espariz, M., Magni, C. Genetic and phenotypic features defining industrial relevant Lactococcus lactis, L. cremoris and L. lactis biovar. diacetylactis strains (2018) Journal of Biotechnology, 282, pp. 25-31. DOI: 10.1016/j.jbiotec.2018.06.345
  • Quintana, I., Espariz, M., Villar, S.R., González, F.B., Pacini, M.F., Cabrera, G., Bontempi, I., Prochetto, E., Stülke, J., Perez, A.R., Marcipar, I., Blancato, V., Magni, C. Genetic engineering of Lactococcus lactis co-producing antigen and the mucosal adjuvant 3' 5'- cyclic di Adenosine Monophosphate (c-di-AMP) as a design strategy to develop a mucosal vaccine prototype (2018) Frontiers in Microbiology, 9 (SEP), art. no. 2100. DOI: 10.3389/fmicb.2018.02100
  • Martino, G.P., Espariz, M., Gallina Nizo, G., Esteban, L., Blancato, V.S., Magni, C. Safety assessment and functional properties of four enterococci strains isolated from regional Argentinean cheese (2018) International Journal of Food Microbiology, 277, pp. 1-9. DOI: 10.1016/j.ijfoodmicro.2018.04.012
  • Mortera, P., Zuljan, F.A., Magni, C., Bortolato, S.A., Alarcón, S.H. Multivariate analysis of organic acids in fermented food from reversed-phase high-performance liquid chromatography data (2018) Talanta, 178, pp. 15-23. DOI: 10.1016/j.talanta.2017.09.005
  • Sauvageot, N., Mokhtari, A., Joyet, P., Budin-Verneuil, A., Blancato, V.S., Repizo, G.D., Henry, C., Pikis, A., Thompson, J., Magni, C., Hartke, A., Deutscher, J. Enterococcus faecalis uses a phosphotransferase system permease and a host colonization-related ABC transporter for maltodextrin uptake (2017) Journal of Bacteriology, 199 (9), art. no. e00878-16. DOI: 10.1128/JB.00878-16
  • Joyet, P., Mokhtari, A., Riboulet-Bisson, E., Blancato, V.S., Espariz, M., Magni, C., Hartke, A., Deutscher, J., Sauvageot, N. Enzymes required for maltodextrin catabolism in Enterococcus faecalis exhibit novel activities (2017) Applied and Environmental Microbiology, 83 (13), art. no. e00038-17. DOI: 10.1128/AEM.00038-17
  • Ficarra, F.A., Santecchia, I., Lagorio, S.H., Alarcón, S., Magni, C., Espariz, M. Genome mining of lipolytic exoenzymes from Bacillus safensis S9 and Pseudomonas alcaliphila ED1 isolated from a dairy wastewater lagoon (2016) Archives of Microbiology, 198 (9), pp. 893-904. DOI: 10.1007/s00203-016-1250-4
  • Zuljan, F.A., Mortera, P., Alarcón, S.H., Blancato, V.S., Espariz, M., Magni, C. Lactic acid bacteria decarboxylation reactions in cheese (2016) International Dairy Journal, 62, pp. 53-62. DOI: 10.1016/j.idairyj.2016.07.007
  • Espariz, M., Zuljan, F.A., Esteban, L., Magni, C. Taxonomic identity resolution of highly phylogenetically related strains and selection of phylogenetic markers by using genome-scale methods: The bacillus pumilus group case (2016) PLoS ONE, 11 (9), art. no. e0163098. DOI: 10.1371/journal.pone.0163098
  • Blancato, V.S., Pagliai, F.A., Magni, C., Gonzalez, C.F., Lorca, G.L. Functional analysis of the citrate activator CitO from Enterococcus faecalis implicates a divalent metal in ligand binding (2016) Frontiers in Microbiology, 7 (FEB), art. no. 101. DOI: 10.3389/fmicb.2016.00101
  • Martino, G.P., Quintana, I.M., Espariz, M., Blancato, V.S., Magni, C. Aroma compounds generation in citrate metabolism of Enterococcus faecium: Genetic characterization of type I citrate gene cluster (2016) International Journal of Food Microbiology, 218, pp. 27-37. DOI: 10.1016/j.ijfoodmicro.2015.11.004

Collaborators

  • Dra. Lopez, Paloma, Consejo Superior de Investigaciones Científicas. Estructura y Función de Proteinas. Centro de Investigaciones Biológicas. E-mail: plg@cib.csic.es; Velázquez 144. 28006 Madrid, España.
  • Dr. Juke S. Lolkema, Dpto. de Microbiología. Groningen Biomolecular Sciences and Biotechnology Institute. University of Groningen. Email: j.s.lolkema@rug.nl; Kerklaan 30. 9751 NN Haren Gn, Holanda.
  • Dr. Josef Deustcher. Laboratoire de Génétique des Microorganismes, Thiverval-Grignon, Francia.
  • Dr. Nicolas Sauvageot. Normandie University, UNICAEN, U2RM Stress/Virulence, Caen, France.
  • Dr. Axel Hartke. Normandie University, UNICAEN, U2RM Stress/Virulence, Caen, France.
  • DR. Jörg Stülke. Department of General Microbiology, GZMB, Georg-August-Universität Göttingen, Göttingen, Germany.

Grants

  • Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET).
  • Agencia Nacional de Promoción Científica y Tecnológica (ANPCyT).
  • Fermentation of Food Products: “Controlling Biogenic Amines in Traditional Food Fermentations in Regional Europe” de la Comision de Comunidades Europeas “Quality of Life and Management of Living Resources”. Director Juke Lolkema, 2009-2011.
  • Proyecto de colaboración Internacional Eco-SUD Mincyt (Argentina) - (Francia) Responsable Dr. Ch Magni, Dr. J. Deutscher. “Mecanismos moleculares de la represión catábolica en bacterias grampositivas”. 2010-2012.

Director

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Magni, Christian
Core Faculty
Email: magni@ibr-conicet.gov.ar
Phone: +54 341 4350596/4350661
Office Extension: 120
Laboratory Extension: 118

Researchers

  • Víctor Blancato
  • Martín Espariz

Doctoral fellows

  • Giuliana Acciarri
  • Mariano A. Torres Manno

Undergraduate Students

  • Fernán Gizzi
  • Alejo Casal

Other Personnel

  • Josefina Lógica (Pasante)

Imágenes

Metabolismo de citrato en Bacterias Lácticas.