Group Leader/s



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.


Notararigo S, Varela E, Otal A, Cristobo I, Antolín M, Guarner F, Prieto A, López P.  [2021]. Evaluation of an O2-Substituted (1–3)-β-D-Glucan, Produced by Pediococcus parvulus 2.6, in ex vivo Models of Crohn’s Disease

Zarour K, Llamas Mª Goretti, Prieto A, Rúas-Madiedo P, Dueñas MT, Fernández de Palencia P., Aznar R, Kihal M, López, P.  [2017]. Rheology and bioactivity of high molecular weight dextrans synthesised by lactic acid bacteria. Carbohy. Polym. 174: 646–657. 0144-8617

Ruiz-Masó JA, Machón C, Bordanaba-Ruiseco L, Espinosa M, Coll M del Solar G  [2015]. Plasmid rolling circle replication. Microbiol Spectrum 3 (1). doi:10.1128/microbiolspec.PLAS-0035-2014

Notararigo S, de las Casas-Engel M, Fernández de Palencia P, Corbí AL, López P  [2014]. 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.



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