Anabaena Azollae
Mostrando 1-12 de 12 artigos, teses e dissertações.
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1. A azolla e a cultura arrozeira.
A planta Azolla; A alga Anabaena; A associação Azolla-Anabaena; Fixação biológica de nitrogênio no sistema; Nitrogênio fixado e acumulado em Azolla; A Azolla como adubo verde em arroz; Desenvolvimento do inóculo no campo; Desenvolvimento da Azolla em local definitivo; Modo de utilização da Azolla em arrozais; Resultados da utilização da Azolla em
Goiânia. Publicado em: 2011
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2. Seleção de espécies e ecótipos de azolla.
Foram feitos dois experimentos no campo, com dez ecótipos de diferentes espécies, em diferentes épocas (maio a novembro de 1985), com o objetivo de selecionar-se espécie/ecótipo de Azolla eficientes, observando-se a produção (peso da matéria viva), taxa de crescimento relativo (g/g de inóculo dia-1), tempo de duplicação e pigmentação (clorofila
Goiânia: EMBRAPA-CNPAF. Publicado em: 2011
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3. A azolla e a cultura arrozeira.
A azolla é uma planta aquática; possui uma alga capaz de absorver o nitrogênio do ar atmosférico, vivendo no interior de suas folhas. Atualmente, tem sido mais utilizada como fonte de nitrogênio e outros macro e micronutrientes na cultura arrozeira irrigada e como aceleradora da decomposição da palhada do arroz, facilitando o melhoramento do solo para
Goiânia: EMBRAPA-CNPAF. Publicado em: 2011
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4. The Azolla, Anabaena azollae Relationship: I. Initial Characterization of the Association 1
Cultures of Azolla caroliniana Willd. free of the symbiotic blue-green alga, Anabaena azollae, were obtained by treatment of Azolla fronds with a regimen of antibiotics. These symbiontfree plants can be maintained only on medium containing a combined nitrogen source.
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5. DNA Probes Show Genetic Variation in Cyanobacterial Symbionts of the Azolla Fern and a Closer Relationship to Free-Living Nostoc Strains than to Free-Living Anabaena Strains
Twenty-two isolates of Anabaena azollae derived from seven Azolla species from various geographic and ecological sources were characterized by DNA-DNA hybridization. Cloned DNA fragments derived from the genomic sequences of three different A. azollae isolates were used to detect restriction fragment length polymorphism among all symbiotic anabaenas. DNA clo
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6. Azolla-Anabaena azollae Relationship: IV. Photosynthetically Driven, Nitrogenase-catalyzed H2 Production 12
The water fern, Azolla caroliniana Willd., containing the symbiotic, heterocystous blue-green alga, Anabaena azollae, has been studied under various growth conditions to characterize its light-dependent production of H2. The response of H2 production to N2 and C2H2 and the absence of a differential effect of m-chlorocarbonyl cyanide phenylhydrazone on H2 pro
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7. The Azolla-Anabaena azollae Relationship 1: XI. PHYCOBILIPROTEINS IN THE ACTION SPECTRUM FOR NITROGENASE-CATALYZED ACETYLENE REDUCTION
Visible absorption spectra are presented for the Azolla caroliniana Willd.-Anabaena azollae Strass. association and the individual partners. Although absorption by the phycobiliproteins of the endophytic cyanobacterium clearly complements the absorption by the fern pigments, their contribution to the absorption spectrum of the association is effectively conc
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8. Azolla-Anabaena azollae Relationship: V. 15N2 Fixation, Acetylene Reduction, and H2 Production 12
In order to characterize the reactions catalyzed by nitrogenase in the Azolla-Anabaena association, 15N2 fixation, C2H2 reduction, and ATP-dependent H2 production were measured in both the Azolla-Anabaena complex and in the alga isolated from the complex.
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9. The Azolla, Anabaena azollae Relationship: II. Localization of Nitrogenase Activity as Assayed by Acetylene Reduction 1
Anaerobic (microaerophilic) acetylene reduction by Azolla caroliniana Willd. was dependent on light and saturated at approximately 450 foot candles. Maximum rates of acetylene reduction were 60 nmoles/mg chlorophyll minute. However, rates of 25 to 30 nmoles/mg chlorophyll minute were more common.
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10. Azolla-Anabaena Relationship 1: XIII. Fixation of [13N]N2
The major radioactive products of the fixation of [13N]N2 by Azolla caroliniana Willd.-Anabaena azollae Stras. were ammonium, glutamine, and glutamate, plus a small amount of alanine. Ammonium accounted for 70 and 32% of the total radioactivity recovered after fixation for 1 and 10 minutes, respectively. The presence of a substantial pool of [13N]N2-derived
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11. Azolla filiculoides Nitrogenase Activity Decrease Induced by Inoculation with Chlamydomonas sp. †
Experiments were conducted to determine the influence of Chlamydomonas sp. on nitrogen fixation (C2H2 → C2H4) in Azolla filiculoides and on the nitrogen fixation and growth of free-living Anabaena azollae 2B organisms. Inoculation of azolla medium with Chlamydomonas sp. was associated with decreased nitrogenase activity in A. filiculoides and with increase
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12. Cotranscription of genes encoding the small and large subunits of ribulose-1,5-bisphosphate carboxylase in the cyanobacterium Anabaena 7120.
In the filamentous cyanobacterium Anabaena, the gene for the small subunit (rbcS) of ribulose-1,5-bisphosphate carboxylase is linked to and transcribed together with the gene encoding the large subunit (rbcL) of the same enzyme. The two genes are separated by a spacer of 545 base pairs (bp) that does not contain an open reading frame. Both genes hybridize wi