Nitrogen Metabolism

Eulogio J. Bedmar (PI)

Professor CSIC

A-3641-2008

0000-0002-9421-1460

eulogio.bedmar@eez.csic.es

PHONE NUMBER

+34-958-181-600 ext. 273

Other group members

María Jesús Delgado Igeño

Scientific Researcher CSIC

María Socorro Mesa Banqueri

Tenured Scientist CSIC

Germán Tortosa Muñoz

Técnico Especializado

Andrea Jiménez Leiva

Postdoc, Junta de Andalucía

Alba Hidalgo García

Indefinido no fijo

Sergio Parejo Treviño

Predoc FPU

Pedro José Pacheco Márquez

Predoc FPU

Noemí Fernández Fernández

Predoc

Safia Boukhedami

Estudiante Predoctoral

Universidad de Bejaia, Algeria

Silko Mergenthal

Estudiante Erasmus

Universidad de Nijmegen, Holanda

Research lines

  • Study the environmental factors, genes, enzymes and redox processes involved in the denitrification of legume endosymbiotic bacteria
  • Unravel the molecular mechanisms that control the expression, activity and regulation of denitrification and nitrogen fixation-related processes during symbiosis
  • Analyse the molecular ecology of nitrifying and denitrifying bacteria in soils, waters and sediments contaminated with nitrates. Effect of nitrogen fertilization
  • Determine the biotic, abiotic and regulatory factors involved in reducing the emission of the greenhouse gas nitrous oxide in the symbiotic fixation of N2-denitrification processes

Representative publications

  • Tortosa G, Pacheco PJ, Hidalgo-García A, Granados A, Delgado A, Mesa S, Bedmar EJ, Delgado MJ (2020) Copper modulates nitrous oxide emissions from soybean root nodules. Environ Exp Bot (doi.org/10.1016/j.envexpbot.2020.104262).
  • Castellano-Hinojosa A, Charteris AF, Müller C, Jansen-Willems A, González-López J, Bedmar EJ, Carrillo P. Cárdenas LM (2020) Occurrence and 15N-quantification of simultaneous nitrification and denitrification in N-fertilized soils incubated under oxygen-limiting conditions. Soil Biol Biochem (doi.org/10.1016/j.soilbio.2020.107757).
  • Salas A, Tortosa Muñoz G, Hidalgo-García A, Delgado-Huertas A, Bedmar EJ, Richardson D, Gates AJ, Delgado MJ (2020) The haemoglobin Bjgb from Bradyrhizobium diazoefficiens controls NO homeostasis in soybean nodules to protect symbiotic nitrogen fixation. Front Microbiol (doi).
  • Hidalgo-García A, Torres MJ, Salas A, Bedmar EJ, Girard L, Delgado MJ (2019) Rhizobium etli produces nitrous oxide by coupling the assimilatory and denitrification pathways. Front Microbiol (doi: 10.3389/fmicb.2019.00980).
  • Castellano-Hinojosa A, Correa-Galeote D, González-López J, Bedmar EJ (2019) Effect of nitrogen fertilizers on nitrous oxide emission, nitrifier and denitrifier abundance and bacterial diversity in closed ecological systems. App Soil Ecol (doi: 10.1016/j.apsoil. 2019.103380).
  • Jiménez-Leiva A, Cabrera JJ, Bueno E, Torres MJ, Salazar S, Bedmar EJ, Delgado EJ, Mesa S (2019) Expanding the regulon of the Bradyrhizobium diazoefficiens NnrR transcription factor: new insights into the denitrification pathway. Front Microbiol 10: 1926 (doi: 10.3389/fmicb.2019.01926).
  • Fernández N, Cabrera, JJ, Varadarajan AR, Lutz S, Ledermann R, Roschitzki B, L. Eberl L, Bedmar EJ, Fischer HM, Pessi G, Ahrens CH, Mesa S (2019) An integrated approach unveils new aspects of microoxia-mediated regulation in diazoefficiens. Front Microbiol 10: 924. (doi: 10.3389/fmicb.2019.00924).
  • Torres MJ, Avila S, Bedmar EJ, Delgado MJ (2018) Overexpression of the periplasmic nitrate reductase supports anaerobic growth by Ensifer meliloti. FEMS Microbiol Lett 365: 041 (doi: 10.1093/femsle/fny041).
  • Castellano-Hinojosa A. González-López J, Bedmar, EJ (2018) Distinct effect of nitrogen fertilisation and soil depth on nitrous oxide emissions and nitrifiers and denitrifiers abundance. Biol Fertility Soils (doi: 10.1007/s00374-018-1310-9).
  • Bueno E, Robles E, Torres MJ, Krell T, Bedmar EJ, Delgado MJ, Mesa S (2017) Disparate response to microoxia and nitrogen oxides of the Bradyrhizobium japonicum napEDABC, nirK and norCBQD denitrification genes. Nitric Oxide 68: 137-149.
  • Torres MJ, Simon J, Rowley G, Bedmar EJ, Richardson DJ, Gates AJ, Delgado MJ (2016) Nitrous oxide metabolism in nitrate-reducing bacteria: physiology and regulatory mechanisms. In: Advances in Microbial Physiology, vol 68 (Poole RK, ed.) pp 353-432. (doi:10.1016/bs.ampbs.2016.02.007).
  • Cabrera JJ, Salas A, Torres MJ, Bedmar EJ, Richardson DJ, Gates AJ, Delgado MJ (2016) An integrated system for nitrate assimilation and nitric oxide detoxification in Bradyrhizobium japonicum. Biochem J 473: 297-309.
  • Bueno E, Mania D, Frostegard Ǻ, Bedmar EJ, Bakken LR, Delgado MJ (2015) Anoxic growth of Ensifer meliloti 1021 by N2O-reduction, a potential mitigation strategy. Front Microbiol 27: (doi: 10.3389/fmicb.2015.00537).
  • Peix A, Ramírez-Bahena MH, Velázquez E, Bedmar EJ (2015) Bacterial associations with legumes. Critical Rev Plant Sci 34: 17-42.
  • Bonnet M, Kurz K, Mesa S, Briand C, Hennecke H, Grütter M (2013) Structure of Bradyrhizobium japonicum transcription factor FixK2 unveils sites of DNA binding and oxidation. J Biol Chem 288: 14238-14246.

Grants

  • Delgado MJ (IP), Mesa MS (co-IP), Bedmar EJ (participant) (2021-2023) Integrated study of the mechanisms that affect the production of greenhouse gases by endosymbiotic bacteria of legumes. Project of Excellence from Junta de Andalucía. P18-RT-1401.
  • Delgado MJ (IP), Bedmar EJ (participant) (2018-2021) Emission of nitric oxide and nitrous oxide by legume crops: Processes involved, their control and mitigation strategies. Ministry of Science and Innovation. AGL2017-85676-R.
  • Mesa MS (IP), Bedmar EJ (participant) (2016-2021) Dissection of the regulatory network that controls the FixK2 protein of Bradyrhizobium diazoefficiens, a key transcriptional factor for symbiosis. Ministry of Economy and Competitiveness. AGL2015-63651-P. Extended by an extraordinary grant from CSIC (2019AEP193).
  • Bedmar EJ (IP), Delgado MJ (participant) and MS Mesa (participant) (2014-2019) Emission of nitrous oxide by soils cultivated with legumes and vegetables of agricultural interest (Nitroleg, P12-AGR-1968). Motive Project of Junta de Andalucía.
  • Bedmar EJ (IP), Delgado (participant) and Mesa MS (participant) (2014-2015) Emission of nitrous oxide by soils cultivated with legumes and vegetables of agricultural interest and bacterial biodiversity associated with nitrogen fertilization. Special project RECUPERA 2020 in collaboration with Ministry of Economy and Competitiveness-CSIC. CSIC-902022130007.

Relevant methods

  • Gas chromatography for detection of greenhouse gases and others
  • Nitric oxide (NO) detection through the use of specific electrodes
  • Cytochrome c detection c (heme staining)
  • Western-blot and protein immunodetection
  • Expression and purification of proteins (recombinant and genuine)
  • Affinity chromatography, molecular exclusion, ion exchange
  • DNA isolation from environmental samples
  • N-cycle genes amplification from environmental samples
  • Mass sequencing. Illumina
  • Isolation of RNA from free-living cultures and from nodules
  • Analysis of gene expression using transcriptional fusions, qRT-PCR and microarrays
  • In vitro transcription
  • Characterization of promoters using primer extension techniques (RACE, FLOE, primer extension, etc.)
  • Protein-DNA interaction through surface plasmon resonance (SPR) and through isothermal titration calorimetry (ITC)
  • Transcriptomics and proteomics

Collaborations with other national and international research groups

  • Christian Ahrens (Agroscope and Swiss Institute of Bioinformatics, Switzerland)
  • Gregorio Arone (National University of Barranca, Peru)
  • Xavier Barril (University of Barcelona, Spain)
  • Fabricio Cassán (National University of Río Cuarto, Argentina)
  • Antonio Castellano-Hinojosa (University of Florida, USA)
  • Antonio De Ron (Misión Biológica de Galicia-CSIC, Spain)
  • Elena Evguenieva-Hackenberg (Justus-Liebig-Universität Giessen, Alemania
  • Hans Martin Fischer (Swiss Federal Institute of Technology-ETH, Switzerland)
  • Lourde Girard (Center for Genomic Sciences, UNAM, México)
  • Jesús González (University of Granada, Spain)
  • Carmen González Murúa (Basque Country University EHU, Spain)
  • Juan Mamuel Medina (University of Granada)
  • Mustapha Missbah El Idrissi Mohammed V (University, Morocco)
  • Álvaro Peix (Instituto de Recursos Naturales-CSIC, Spain)
  • Gabriella Pessi y Leo Eberl (University of Zürich, Suiza)
  • Juan Ignacio Quelas (National University of La Plata/National Council for Scientific and Technical Research, Argentina)
  • Miguel Quemada (Politechnical University of Madrid, Spain)
  • David Richardson and Andrew Gates (University of East Anglia, UK)
  • Laura Tomás-Gallardo (Andalusian Center for Development Biology, Pablo de Olavide University-CSIC, Spain)
  • Toshiki Uchiumi (University of Kagoshima, Japan)
  • Renzo Valdez (National University of Barranca, Peru)
  • Antonio Vallejo (Politechnical University of Madrid, Spain)