Diazotrophic Bacterium
Mostrando 13-22 de 22 artigos, teses e dissertações.
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13. Presence of a Vanadium Nitrogenase in Azotobacter paspali
There have been no previous studies on the genetics of Azotobacter paspali, an aerobic bacterium which forms a highly specific diazotrophic association with Bahia grass (Paspalum notatum). We constructed A. paspali strains defective in the molybdenum nitrogenase so that alternative N2ases could be studied. The cosmid vector pTBE and genomic DNA fragments (�
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14. Nitrogen fixation by the thermophilic green sulfur bacterium Chlorobium tepidum.
The thermophilic green sulfur bacterium Chlorobium tepidum grew with N2, NH4+, or glutamine as the sole nitrogen source under phototrophic (anaerobic-light) conditions. Growth on N2 required increased buffering capacity to stabilize uncharacterized pH changes that occurred during diazotrophic growth. Increased sulfide levels were stimulatory for growth on N2
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15. Role of GlnK in NifL-Mediated Regulation of NifA Activity in Azotobacter vinelandii
In several diazotrophic species of Proteobacteria, PII signal transduction proteins have been implicated in the regulation of nitrogen fixation in response to NH4+ by several mechanisms. In Azotobacter vinelandii, expression of nifA, encoding the nif-specific activator, is constitutive, and thus, regulation of NifA activity by the flavoprotein NifL appears t
American Society for Microbiology.
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16. Burkholderia, a Genus Rich in Plant-Associated Nitrogen Fixers with Wide Environmental and Geographic Distribution
The genus Burkholderia comprises 19 species, including Burkholderia vietnamiensis which is the only known N2-fixing species of this bacterial genus. The first isolates of B. vietnamiensis were recovered from the rhizosphere of rice plants grown in a phytotron, but its existence in natural environments and its geographic distribution were not reported. In the
American Society for Microbiology.
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17. Catabolic thiosulfate disproportionation and carbon dioxide reduction in strain DCB-1, a reductively dechlorinating anaerobe.
Strain DCB-1 is a strict anaerobe capable of reductive dehalogenation. We elucidated metabolic processes in DCB-1 which may be related to dehalogenation and which further characterize the organism physiologically. Sulfoxy anions and CO2 were used by DCB-1 as catabolic electron acceptors. With suitable electron donors, sulfate and thiosulfate were reduced to
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18. Identification of Two New Genes Involved in Diazotrophic Growth via the Alternative Fe-Only Nitrogenase in the Phototrophic Purple Bacterium Rhodobacter capsulatus
Growth of Rhodobacter capsulatus with molecular dinitrogen as the sole N source via the alternative Fe-only nitrogenase requires all seven gene products of the anfHDGK-1-2-3 operon. In contrast to mutant strains carrying lesions in the structural genes of nitrogenase (anfH, anfD, anfG, and anfK), strains defective for either anf1, anf2, or anf3 are still abl
American Society for Microbiology.
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19. Global changes in protein composition of N2-fixing-Azoarcus sp. strain BH72 upon diazosome formation.
The strictly respiratory, diazotrophic bacterium Azoarcus sp. strain BH72 fixes nitrogen under microaerobic conditions. In empirically optimized batch cultures at nanomolar O2 concentrations in the presence of proline, cells can shift into a state of higher activity and respiratory efficiency of N2 fixation in which intracytoplasmic membrane stacks (diazosom
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20. Requirement of a Relatively High Threshold Level of Mg2+ for Cell Growth of a Rhizoplane Bacterium, Sphingomonas yanoikuyae EC-S001
Mg2+ is one of the essential elements for bacterial cell growth. The presence of the magnesium cation (Mg2+) in various concentrations often affects cell growth restoration in plant-associating bacteria. This study attempted to determine whether Mg2+ levels in Sphingomonas yanoikuyae EC-S001 affected cell growth restoration in the host plant and what the thr
American Society for Microbiology.
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21. Augmented rates of respiration and efficient nitrogen fixation at nanomolar concentrations of dissolved O2 in hyperinduced Azoarcus sp. strain BH72.
Azoarcus sp. strain BH72 is an aerobic diazotrophic bacterium that was originally found as an endophyte in Kallar grass. Anticipating that these bacteria are exposed to dissolved O2 concentrations (DOCs) in the nanomolar range during their life cycle, we studied the impact of increasing O2 deprivation on N2 fixation and respiration. Bacteria were grown in ba
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22. Cell biology and molecular basis of denitrification.
Denitrification is a distinct means of energy conservation, making use of N oxides as terminal electron acceptors for cellular bioenergetics under anaerobic, microaerophilic, and occasionally aerobic conditions. The process is an essential branch of the global N cycle, reversing dinitrogen fixation, and is associated with chemolithotrophic, phototrophic, dia