The nitrogen fix
نویسندگان
چکیده
منابع مشابه
Streptomyces thermoautotrophicus does not fix nitrogen.
Streptomyces thermoautotrophicus UBT1 has been described as a moderately thermophilic chemolithoautotroph with a novel nitrogenase enzyme that is oxygen-insensitive. We have cultured the UBT1 strain, and have isolated two new strains (H1 and P1-2) of very similar phenotypic and genetic characters. These strains show minimal growth on ammonium-free media, and fail to incorporate isotopically lab...
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A new study asserts that a late evolutionary leap in cyanobacterial nitrogen fixation terminated a long history of nitrogen-limited primary production in the ocean--and contributed to a dramatic increase in biospheric oxygen coincident with the rise of animals.
متن کاملSanctions and mutualism stability: why do rhizobia fix nitrogen?
Why do rhizobia expend resources on fixing N(2) for the benefit of their host plant, when they could use those resources for their own reproduction? We present a series of theoretical models which counter the hypotheses that N(2) fixation is favoured because it (i) increases the exudation of useful resources to related rhizobia in the nearby soil, or (ii) increases plant growth and therefore th...
متن کاملMutants of azotobacter that do not fix nitrogen.
Stable strains of mutants of Azotobacter that do not fix nitrogen are difficult to obtain by traditional procedures (Karlsson and Barker, 1948; Lindstrom, 1948). Stumbo and Gainey (1938) demonstrated that culturing Azotobacter on a high nitrate medium resulted in strains that failed to fix nitrogen even after continued transfer in the absence of fixed nitrogen. However, since these strains were...
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Eventually, the algorithm for when to intervene on the tricuspid valve during left sided valve surgery will be more robust. Better discriminatory preoperative data will be required to sort the role of annular size, right ventricular function, and pulmonary artery pressures. As for now, there is a paucity of evidence that an aggressive approach to fixing moderate functional TR during left sided ...
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ژورنال
عنوان ژورنال: Nature
سال: 2001
ISSN: 0028-0836,1476-4687
DOI: 10.1038/35083660