This group studies several aspects of the biology of Gram-positive bacteria which impact on human health, such as their interaction with eukaryotic cells, their plasmids and their metabolites.
Gram-positive bacteria include pathogenic organisms, such as species belonging to the Streptococcus genus but also others strains that are beneficial to human health. Among the latter are lactic acid bacteria (LAB), some of which are considered to be probiotic. Likewise, there are a number of metabolites produced by these organisms, such as vitamins as well as certain polysaccharides (prebiotics) whose functions, among others, is to enhance the development of a microbiota that is beneficial to the human gastrointestinal tract, as well as possibly possessing an immunomodulating effect. These aspects constitute an important field of research that could lead to the production of fermented functional foods (and beverages) which benefit human health. In addition, our research also involves the study of plasmids present in the Gram-positive bacterial genomes, which have a beneficial effect, due to their encoding metabolic pathways, whose products are of nutritional value. However, the presence of these plasmids could also have a detrimental effect, when they encode determinants for antibiotic resistance and are present in pathogenic bacteria i.e. Streptococcus pneumoniae or Staphylococcus aureus.
Bearing in mind the above, our work group is pursuing the following lines of research: 1) A study of the probiotic potential of Lactobacillus, Leuconostoc and Pediococcus and strains that produce homopolysaccharides, and a physiochemical and biochemical/biological evaluation of the produced polysaccharides, 2) Development and characterization of food grade riboflavin- and dextran-overproducing lactic acid bacteria to generate enriched-cereal based and -dairy functional food. 3) Study of both the replication and the regulation of gene expression at the molecular, biochemical and structural levels, using plasmids of Gram-positive bacteria as model systems. 4) Development of plasmid vectors for analysis of gene expression, using fluorescent proteins as reporter and the characterisation of their suitability for fluorescent labelling in Gram-positive bacteria. 5) Interactomic studies of bacteria with eucaryotic cells to analyse the performance of probiotic lactic acid bacteria in the gut context.
Besrour-Aouam N, Fhoula I, Hernández-Alcántara AM, Mohedano ML, Najjari A, Prieto A, Ruas-Madiedo P, López P and Ouzari H-I. . The role of dextran production in the metabolic context of Leuconostoc and Weissella Tunisian strains. Carbohy. Polym.253:117254.
Hernández-Alcántara A, Pardo S, Mohedano ML, Vignolo G, de Moreno de LeBlanc A, LeBlanc JG, Aznar R and López P. . The ability of riboflavin-overproducing Lactiplantibacillus plantarum strains to survive under gastrointestinal conditions. Front. Microbiol. 11:591945
Mohedano ML, Hernández-Recio S, Yépez A, Requena T, Martínez-Cuesta MC, Peláez C, Russo P, LeBlanc JG, Spano G, Aznar R and López P . Real-time detection of riboflavin production by Lactobacillus plantarum strains and tracking of their gastrointestinal survival and functionality in vitro and in vivo using mCherry labeling. Frontiers in Microbiology 10(1748). doi: 10.3389/fmicb.2019.0174
Garay-Novillo JN, García-Morena D, Ruiz-Masó JA, Barra JL and del Solar G . Combining modules for versatile and optimal labeling of lactic acid bacteria: two pMV158-family promiscuous replicons, a pneumococcal system for constitutive or inducible gene expression, and two fluorescent proteins. Front Microbiol 10:1431.
Besrour-Aouam N, Mohedano ML, Fhoula I, Zarour K, Najjari A, Aznar R, Prieto A, Ouzari H-I and López P . Different modes of regulation of the expression of dextransucrase in Leuconostoc lactis AV1n and Lactobacillus sakei MN1. Front Microbiol 10(959). doi: 10.3389/fmicb.2019.00959
Pérez-Ramos A, Mohedano ML, Pardo, MA and López P . β-glucan-producing Pediococcus parvulus 2.6: test of probiotic and immunomodulatory properties in zebrafish models. Front. Microbiol. 9:1684. doi: 10.3389/fmicb.2018.01684.
Pérez-Ramos A, Werning ML, Prieto A, Russo P, Spano G. Mohedano ML and López P . Characterization of the sorbitol utilization cluster of the probiotic Pediococcus parvulus 2.6: genetic, functional and complementation studies in heterologous hosts. Front Microbiol 8:2393. https://www.frontiersin.org/articles/10.3389/fmicb.2018.02041/fu
Ruiz-Masó JÁ, Luengo LM, Moreno-Córdoba I, Díaz-Orejas R and del Solar G . Successful establishment of plasmids R1 and pMV158 in a new host requires the relief of the transcriptional repression of their essential rep genes. Front. Microbiol. 8:2367. doi: 10.3389/fmicb.2017.02367
Nácher-Vázquez M, Ruiz-Masó JA, Mohedano ML, del Solar G, Aznar R and López P. . Dextransucrase expression is concomitant with that of replication and maintenance functions of the pMN1 plasmid in Lactobacillus sakei MN1. Front. Microbiol. 8:2281. https://doi.org/10.3389/fmicb.2017.02281
Boer DR, Ruiz-Masó JA, Rueda M, Petoukhov MV, Machón C, Svergun DI, Orozco M, del Solar G, Coll M . Conformational plasticity of RepB, the replication initiator protein of promiscuous streptococcal plasmid pMV158. Sci. Rep. 6, 20915; doi: 10.1038/srep20915
Zarour K, Llamas Mª Goretti, Prieto A, Rúas-Madiedo P, Dueñas MT, Fernández de Palencia P., Aznar R, Kihal M, López, P. . Rheology and bioactivity of high molecular weight dextrans synthesised by lactic acid bacteria. Carbohy. Polym. 174: 646–657. http://dx.doi.org/10.1016/j.carbpol.2017.06.113 0144-8617
López-Aguilar C, Romero-López C, Espinosa M, Berzal-Herranz A, del Solar G . The 5′-tail of antisense RNAII of pMV158 plays a critical role in binding to the target mRNA and in translation inhibition of repB. Front. Genet. 6:225. doi: 10.3389/fgene.2015.00225.
Ruiz-Masó JA, Machón C, Bordanaba-Ruiseco L, Espinosa M, Coll M del Solar G . Plasmid rolling circle replication. Microbiol Spectrum 3 (1). doi:10.1128/microbiolspec.PLAS-0035-2014
Nácher-Vázquez M, Ballesteros N, Canales A, Rodríguez Saint-Jean S, Pérez-Prieto SI, Prieto A, Aznar R, López P . Dextrans produced by lactic acid bacteria exhibit antiviral and immunomodulatory activity against salmonid viruses. Carbohy. Polym. 124:292-301
Notararigo S, de las Casas-Engel M, Fernández de Palencia P, Corbí AL, López P . Immunomodulation of human macrophages and myeloid cells by 2-substituted (1-3)-β-D-glucan from P. parvulus 2.6. Carbohy Polym 112:109–113. Doi: 10.1016/j.carbpol.2014.05
2006-2010. Project AGL2006-11932-C05. Spanish Ministry of Education and Science. Prebiotics and probiotics for elaboration of functional food. Characterisation and evaluation of exopolysaccharides and their producer bacteria. Coordinator: Paloma López.
2006-2010. Project S-BIO-0260. Madrid Autonomy. COMBACT. Coordinator: Miguel Vicente.
2007-2010. Project BFU2007-63575/BMC. Spanish Ministry of Education and Science. Biochemical and structural studies of the pathogenic bacteria Streptococcus pneumoniae and its plasmids. Responsible scientific: Gloria del Solar.
2008-2010. VII Framework Program Project KBBE-CT-2007-211441. European Union (EU). Controlling biogenic amines in traditional food fermentations in regional europe. Responsible scientific at the CIB: Paloma López.
2009-2013. VII Framework Program Project FP7-PEOPLE-ITN-2008-238490. UE: Scientific Training in Antimicrobial Research Strategies. EU: Responsible scientific at the CIB: Paloma López.
2009-2015. Subprogram CONSOLIDER-INGENIO 2010 Project CSD00C-08-41920. Spanish Ministery of Science and Innovation. Coordinator: Manuel Espinosa.
2010-2014. Project AGL2009-12998-C03. Spanish Ministry of Science and Innovation. Glucan producing Lactobacilli and Pediococci strains. Evaluation of their probiotic characteristics and analysis of the physico-chemical and functional properties of their exopolysaccharides. Coordinator: Paloma López.
2011-2015. Project BFU2010-19597/BMC. Spanish Ministry of Science and Innovation. Streptococcus pneumoniae and its promiscuous plasmid pMV158: monologs, dialogs and intercomunications. Responsible scientific: Gloria del Solar.
2012-2014. Project BFU2011-14145-E. Spanish Ministry of Science and Innovation. Spanish network of plasmids and another movil elements (REDEEX-2). Coordinator: Gloria del Solar.
2013-2016. Project AGL2012-40084-C03. Spanish ministry of Economy and Competitiveness. Identification of immunomodulating prebiotic polysaccharides and probiotic bacteria for use in novel functional food. Coordinator: Paloma López.
2015-2017. Project BIO2015-69085-REDC. Interactions between plasmidic and chromosomal bacterial modules: a due visit. Spanish Ministry of Economy and Competitiveness. Coordinator: Antonio Juárez.
2015-2018. Project AGL2015-71923-REDT. Spanish Ministry of Economy and Competitiveness. Lactic acid bacteria and their relationship with health, quality and security of food (RedBAL). Responsible scientific at CIB: Paloma López. Coordinator: Patricia Ruas.
2015-2018. Project BIO2015-69085-REDC. Interactions between plasmidic modules and bacterial chromosomes: a due visit. Spanish Ministry of Economy and Competitiveness. Gloria del Solar: member of the research team. Coordinator: Antonio Juárez.
2016-2019. Project AGL2015-65010-C3-1-R. Spanish Ministry of Economy and Competitiveness. Development and evaluation of functional food based in bacterial homopolysaccharides.Responsible scientific: Paloma López.
2017-2019. Project MHE200027 within the frame of the program EMHE-CSIC 2016 for the co-direction of the Doctoral Thesis of Javier Nicolás Garay-Novillo. Co-supervisors: José Luis Barra (CIQUIBIC-CONICET, Córdoba, Argentina) and Gloria del Solar.
2017-2020. Projects CYTED 917PTE0537 and PCIN-2017-075. Iberoamerican program for development of science and technology and Spanish Minestry of Economy, Industry and Competitiveness. Vegetal food with probiotic functionality for undernourised infant population. Responsible scientific at CIB: Paloma López. Coordinator: Patricia Ruas.
2018-2019. Project 2011820E078. CSIC. Proteomic characterization of the heat- and acid-shock responses of probiotic lactic acid bacteria. Responsible scientific. Paloma López.
2019-2023. Project RTI2018-097114-B-I00. Spanish Minestry of Science, Innovation and Universities. Selection and characterization of lactic acid bacteria that overproduce vitamin B2 and dextran for the development of functional bread and dairy products. Responsible Scientifics: Paloma López and Gloria del Solar.
2019-20023. Cost Action CA1801. The European Cooperation in Science and Technology (COST). SOURDOugh biotechnology network towards novel, healthier and sustainable food and bIoproCesseS (Sourdomics). Participants at CIB: Paloma López and Gloria del Solar.