|
|
|
|
|
| Tang, Weiyi; Cassar, Nicolas. |
| Diazotrophs play a critical role in the biogeochemical cycling of nitrogen, carbon, and other elements in the global ocean. Despite their well‐recognized role, the diversity, abundance, and distribution of diazotrophs in the world's ocean remain poorly characterized largely due to limited observations. Here we update the database of diazotroph nifH gene abundances and assess how environmental factors may regulate diazotrophs at the global scale. Our meta‐analysis more than doubles the number of observations in the previous database. Using linear and nonlinear regressions, we find that the abundances of Trichodesmium, UCYN‐A, UCYN‐B, and Richelia relate differently to temperature, light, and nutrients. We further apply a random forest algorithm to estimate... |
| Tipo: Text |
Palavras-chave: Diazotrophs; Marine nitrogen fixation; Meta-analysis; Machine learning. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00591/70322/68359.pdf |
| |
|
|
| Pupier, Chloe A.; Bednarz, Vanessa N.; Grover, Renaud; Fine, Maoz; Maguer, Jean-francois; Ferrier-pages, Christine. |
| Corals are associated with dinitrogen (N-2)-fixing bacteria that potentially represent an additional nitrogen (N) source for the coral holobiont in oligotrophic reef environments. Nevertheless, the few studies investigating the assimilation of diazotrophically derived nitrogen (DDN) by tropical corals are limited to a single scleractinian species (i.e., Stylophora pistillata). The present study quantified DDN assimilation rates in four scleractinian and three soft coral species from the shallow waters of the oligotrophic Northern Red Sea using the N-15(2) tracer technique. All scleractinian species significantly stimulated N, fixation in the coral-surrounding seawater (and mucus) and assimilated DDN into their tissue. Interestingly, N-2 fixation was not... |
| Tipo: Text |
Palavras-chave: Dinitrogen fixation; Diazotrophs; Scleractinian corals; Soft corals; Red Sea. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00512/62370/66644.pdf |
| |
|
|
| Baldani,José I.; Baldani,Vera L.D.. |
| This review covers the history on Biological Nitrogen Fixation (BNF) in Graminaceous plants grown in Brazil, and describes research progress made over the last 40 years, most of whichwas coordinated by Johanna Döbereiner. One notable accomplishment during this period was the discovery of several nitrogen-fixing bacteria such as the rhizospheric (Beijerinckia fluminensis and Azotobacter paspali), associative (Azospirillum lipoferum, A. brasilense, A. amazonense) and the endophytic (Herbaspirillum seropedicae, H. rubrisubalbicans, Gluconacetobacter diazotrophicus, Burkholderia brasilensis and B. tropica). The role of these diazotrophs in association with grasses, mainly with cereal plants, has been studied and a lot of progress has been achieved in the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Bacterial endophytes; Diazotrophs; Semi-solid N-free medium; Inoculation; Cereals; Grass plants. |
| Ano: 2005 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652005000300014 |
| |
|
|
| Reinhardt,Érica. L.; Ramos,Patrícia L.; Manfio,Gilson P.; Barbosa,Heloiza R.; Pavan,Crodowaldo; Moreira-Filho,Carlos A.. |
| Fourteen strains of nitrogen-fixing bacteria were isolated from different agricultural plant species, including cassava, maize and sugarcane, using nitrogen-deprived selective isolation conditions. Ability to fix nitrogen was verified by the acetylene reduction assay. All potentially nitrogen-fixing strains tested showed positive hybridization signals with a nifH probe derived from Azospirillum brasilense. The strains were characterized by RAPD, ARDRA and 16S rDNA sequence analysis. RAPD analyses revealed 8 unique genotypes, the remaining 6 strains clustered into 3 RAPD groups, suggesting a clonal origin. ARDRA and 16S rDNA sequence analyses allowed the assignment of 13 strains to known groups of nitrogen-fixing bacteria, including organisms from the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Endophytic bacteria; Diazotrophs; Selective isolation; Molecular systematics. |
| Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822008000300002 |
| |
|
|
| Moura,Ginaini Grazielli Doin de; Armas,Rafael Dutra de; Meyer,Edenilson; Giachini,Admir José; Rossi,Márcio José; Soares,Cláudio Roberto Fonsêca Sousa. |
| ABSTRACT An alternative for recovery of areas degraded by coal mining is revegetation with rapidly growing leguminous trees, which often do not establish in low fertility soils. The objective of this study was to evaluate the efficiency of native rhizobia isolated from coal mining areas in the nodulation and growth of leguminous trees. We isolated 19 strains of rhizobia from a degraded soil near Criciúma, SC, Brazil, and evaluated the nodulation and growth-promoting capacity of the inoculated isolates for bracatinga (Mimosa scabrella), maricá (M. bimucronata) and angico-vermelho (Parapiptadenia rigida). Isolates UFSC-B2, B6, B8, B9, B11 and B16 were able to nodulate bracatinga, providing average increases of 165 % in shoot dry matter, with a significant... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Environmental recovery; Revegetation; Diazotrophs; Bioremediation. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832016000100402 |
| |
|
|
| Saulia, Emmrick; Benavides, Mar; Henke, Britt; Turk-kubo, Kendra; Cooperguard, Haley; Grosso, Olivier; Desnues, Anne; Rodier, Martine; Dupouy, Cécile; Riemann, Lasse; Bonnet, Sophie. |
| Coastal and open ocean regions of the Western Tropical South Pacific ocean have been identified as a hotspot of N2 fixation. However, the environmental factors driving the temporal variability of abundance, composition, and activity of diazotrophs are still poorly understood, especially during the winter season. To address this, we quantified N2 fixation rates and the abundance of seven diazotroph phylotypes (UCYN-A1 symbiosis, UCYN-B, UCYN-C, Trichodesmium, Het-1, Het-2, and Het-3) on a monthly basis during two full years (2012 to 2014) at four stations along a coast to open ocean transect in the New Caledonian lagoon. The total nifH gene concentration (sum of all nifH gene copies) clearly decreased from the barrier reef to the shore. Apart from UCYN-B,... |
| Tipo: Text |
Palavras-chave: N-2 fixation; Diazotrophs; NifH; Abundance; New Caledonia. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00658/77027/78307.pdf |
| |
|
|
| Rigonato,Janaina; Kent,Angela D.; Gumiere,Thiago; Branco,Luiz Henrique Zanini; Andreote,Fernando Dini; Fiore,Marli Fátima. |
| ABSTRACT Variations in microbial communities promoted by alterations in environmental conditions are reflected in similarities/differences both at taxonomic and functional levels. Here we used a natural gradient within mangroves from seashore to upland, to contrast the natural variability in bacteria, cyanobacteria and diazotroph assemblages in a pristine area compared to an oil polluted area along a timespan of three years, based on ARISA (bacteria and cyanobacteria) and nifH T-RFLP (diazotrophs) fingerprinting. The data presented herein indicated that changes in all the communities evaluated were mainly driven by the temporal effect in the contaminated area, while local effects were dominant on the pristine mangrove. A positive correlation of community... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Mangrove; Cyanobacteria; Diazotrophs; Oil contamination; NifH T-RFLP; ARISA. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822018000100087 |
| |
|
|
|
