Growth, heterocyst differentiation and nitrogenase activity in the cyanobacteria Anabaena variabilis and Anabaena cylindrica in response to molybdenum and vanadium
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چکیده
منابع مشابه
Effect of glutamine on growth and heterocyst differentiation in the cyanobacterium Anabaena variabilis.
Mutants of the cyanobacterium Anabaena variabilis that were capable of increased uptake of glutamine, as compared with that in the parental strains, were isolated. Growth of these mutants and their parental strains was measured in media containing N2, ammonia, or glutamine as a source of nitrogen. All strains grew well with any one of these sources of fixed nitrogen. Much of the glutamine taken...
متن کاملHeterocyst differentiation and cell division in the cyanobacterium Anabaena cylindrica: effect of high light intensity.
Heterocyst differentiation in the cyanobacterium Anabaena cylindrica is initiated by the removal of fixed nitrogen from the medium. These specialized cells occur singly at regular intervals within filaments of vegetative cells. Incubation of cultures for periods of up to 12 h immediately prior to or following removal of fixed nitrogen, at a light intensity (500 mi Einsteins cm-2 s-1) approximat...
متن کاملRNA processing of nitrogenase transcripts in the cyanobacterium Anabaena variabilis.
Little is known about the regulation of nitrogenase genes in cyanobacteria. Transcription of the nifH1 and vnfH genes, encoding dinitrogenase reductases for the heterocyst-specific Mo-nitrogenase and the alternative V-nitrogenase, respectively, was studied by using a lacZ reporter. Despite evidence for a transcription start site just upstream of nifH1 and vnfH, promoter fragments that included ...
متن کاملCharacterization of nifB, nifS, and nifU genes in the cyanobacterium Anabaena variabilis: NifB is required for the vanadium-dependent nitrogenase.
Anabaena variabilis ATCC 29413 is a heterotrophic, nitrogen-fixing cyanobacterium containing both a Mo-dependent nitrogenase encoded by the nif genes and V-dependent nitrogenase encoded by the vnf genes. The nifB, nifS, and nifU genes of A. variabilis were cloned, mapped, and partially sequenced. The fdxN gene was between nifB and nifS. Growth and acetylene reduction assays using wild-type and ...
متن کاملAlternative Nitrogenases in Anabaena variabilis: The Role of Molybdate and Vanadate in Nitrogenase Gene
Anabaena variabilis ATCC 29413 has two distinct nitrogenases that function in heterocysts, a conventional Mo-nitrogenase and an alternative V-nitrogenase. Synthesis of these two enzymes was repressed in cells growing with a source of fixed nitrogen, such as ammonium; however, the V-nitrogenase was also repressed by Mo. Expression of the V-nitrogenase which was not affected by V and expression o...
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ژورنال
عنوان ژورنال: New Phytologist
سال: 1997
ISSN: 0028-646X,1469-8137
DOI: 10.1046/j.1469-8137.1997.00666.x