Nitrogen fixation in a non-heterocystous cyanobacterial mat from a mountain river
| Autor: | Esther Berrendero, Claudia L. Gómez, Elvira Perona, Eduardo Fernández Valiente, Virginia Loza, M. Ángeles Muñoz-Martín, Pilar Mateo |
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| Přispěvatelé: | UAM. Departamento de Biología |
| Rok vydání: | 2016 |
| Předmět: |
DNA
Bacterial 0301 basic medicine Cyanobacteria food.ingredient 030106 microbiology Rivularia Article 03 medical and health sciences chemistry.chemical_compound food Rivers Nitrogen Fixation RNA Ribosomal 16S Nitrogenase Botany Phylogeny Phylotype Multidisciplinary biology Botánica DCMU Rivularia colonies Ribosomal RNA 16S ribosomal RNA biology.organism_classification 030104 developmental biology chemistry Nitrogen fixation 16S rRNA gene Schizothrix Nitrogenase activity |
| Zdroj: | Scientific Reports Biblos-e Archivo. Repositorio Institucional de la UAM instname |
| ISSN: | 2045-2322 2008-0239 |
| DOI: | 10.1038/srep30920 |
| Popis: | In situ nitrogen fixation was investigated in a cyanobacterial mat growing on the bed of rocks of the Muga River, Spain. The filamentous non-heterocystous cyanobacterium Schizothrix dominated the mat, showing nitrogenase activity in the light at similar rates to those found in nearby heterocystous Rivularia colonies. N2 fixation in the light was significantly increased by an inhibitor of PSII and oxygen evolution, DCMU (3-[3,4-dichlorophenyl]-1,1-dimethylurea), and anaerobic conditions. However, no nitrogenase activity was found in the dark. Addition of fructose as a respiratory substrate induced nitrogenase activity in samples incubated under aerobic conditions in the dark but not in anaerobic conditions. Microelectrode oxygen profiles showed internal microaerobic microzones where nitrogen fixation might concentrate. Analyses of the 16S rRNA gene revealed only the presence of sequences belonging to filamentous non-heterocystous cyanobacteria. nifH gene diversity showed that the major phylotypes also belonged to this group. One of the three strains isolated from the Schizothrix mat was capable of fixing N2 and growing in the absence of combined N. This was consistent with the nifH gene analysis. These results suggest a relevant contribution of non-heterocystous cyanobacteria to nitrogen fixation in these mats This work was supported by grants from the Ministerio de Ciencia e Innovación and Ministerio de Economía y Competitividad, Spain (CGL2008-02397/BOS and CGL-2013-44870-R), and from the Comunidad Autónoma de Madrid (S2009/AMB-1511). We also thank Professor B A Whitton for helpful suggestions on the manuscript, and Dr Philip Mason for improvements to the English version of our manuscript |
| Databáze: | OpenAIRE |
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