Short-term effect of ammonia on nitrogenase activity of<i>Anabaena variabilis</i>(ATCC29413)

Reich, Sabine; Almon, Helmar; Böger, Peter

doi:10.1111/j.1574-6968.1986.tb01347.x

Cited by 36 publications

(10 citation statements)

References 23 publications

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“…Ceil-free nitrogenase activity was measured with 5 mM sodium dithionite as electron donor and with an ATP-regenerating system present as described [9]. In the case of partially purified components 1 mg BSA × nag -1 was added and the two components (Fe and Mo-Fe protein) were titrated to obtain maximum acetylene-reduction rates [17].…”

Section: Nitrogenase Assay and Preparationmentioning

confidence: 99%

“…Extracts from concentrated filaments were anaerobically prepared with a French-pressure cell with 2 mM sodium dithionite present [9]. The nitrogenase components were isolated by passing the supernatant from a centrifugation step at 200000 × g (120 min) through a DEAE-52 column (Whatman) at room temperature equilibrated with 30 mM Tris-HC1 buffer, pH 7.8, containing 2 mM sodium dithionite to keep anaerobic conditions.…”

Section: Nitrogenase Assay and Preparationmentioning

confidence: 99%

“…Cyanobacteria, as shown for Anabaena variabilis [9], rapidly switch off nitrogenase activity upon addition of ammonia. Evidently, ammonia itself is not the direct effector causing inactivation of nitrogenase.…”

Section: Introductionmentioning

confidence: 95%

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Regulation of nitrogenase activity in Anabaena variabilis by modification of the Fe protein

Reich

1989

FEMS Microbiology Letters

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The nitrogenase components of Anabaena variabilis were isolated to prepare a specific antiserum against the cyanobacterial Fe protein. Thereby, the status of the Fe protein subunits could be analyzed after in‐vivo inactivation of nitrogenase. Firstly, nitrogenase activity was switched off by adding ammonia to intact filaments accompanied with the appearance of a slower migrating subunit of the Fe protein as shown by immunospecific Western blots. Inactivation of nitrogenase was correlated with about equal amounts of modified and non‐modified subunits of the Fe protein. Secondly, a rapid inactivation of nitrogenase was achieved by treatment of cells with oxygen, which was followed by a slow appearance of the modified subunit of the Fe protein.

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Section: Nitrogenase Assay and Preparationmentioning

confidence: 99%

Section: Nitrogenase Assay and Preparationmentioning

confidence: 99%

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Regulation of nitrogenase activity in Anabaena variabilis by modification of the Fe protein

Reich

1989

FEMS Microbiology Letters

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“…Cells were harvested aerobically after 24 h by centrifugation (4,000 x g, 5 min). If necessary, filaments were resuspended and nitrogenase was inactivated by a 1-h ammonium treatment (5 mM) at pH 10 in CAPS buffer (24) or by an 8-h dark incubation (4). All samples were flushed with argon prior to storage in liquid nitrogen.…”

Section: Methodsmentioning

confidence: 99%

In vitro activation of dinitrogenase reductase from the cyanobacterium Anabaena variabilis (ATCC 29413)

et al. 1992

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Nitrogenase of the heterocystous cyanobacterium Anabaena variabilis was inactivated in vivo (S. Reich, H. Almon, and P. Böger, FEMS Microbiol. Lett. 34:53-56, 1986). Partially purified and modified (inactivated) dinitrogenase reductase (Fe-protein) of such cells was reactivated by isolated membrane fractions of A. variabilis or of Rhodospirillum rubrum, and acetylene reduction was measured. Reactivation requires ATP, Mg2+, and Mn2+. The activating principle is localized in the heterocyst and was found effective only when prepared from cells exhibiting active nitrogenase. It also restores the activity of modified Fe-protein from R. rubrum.

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“…High ammonium concentration inhibits heterocyst differentiation and causes a rapid and reversible inhibition of nitrogenase activity [8]. High ammonium concentration inhibits heterocyst differentiation and causes a rapid and reversible inhibition of nitrogenase activity [8].…”

Section: Introductionmentioning

confidence: 99%

Characterization of gonidial zone of Cycas revoluta coralloid roots by means of microelectrodes

Canini¹

1993

FEMS Microbiology Letters

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Microelectrodes were used for measurements of oxygen, ammonium, potassium and calcium concentrations within gonidial zones of Cycas revoluta coralloid roots. Gonidial zone segments contained an oxygen pressure of 85% with respect to its concentration in the atmosphere. Dissolved ammonium was detected in concentrations between × 10−3 M and 4 × 10−3 M. The highest ammonium concentration was in intermedial segments and it could cause the decrease of nitrogenase activity. Potassium concentration was in the range 5.5–9 × 10−3 M; calcium concentration was 10−6 M in apical and subapical segments, it reached 1–2 × 10−5 M in the intermedial and basal segments. Calcium concentrations could affect heterocyst differentiation, nitrogen fixation and mucilage composition of coralloid roots.

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Short-term effect of ammonia on nitrogenase activity ofAnabaena variabilis(ATCC29413)

Cited by 36 publications

References 23 publications

Regulation of nitrogenase activity in Anabaena variabilis by modification of the Fe protein

Regulation of nitrogenase activity in Anabaena variabilis by modification of the Fe protein

In vitro activation of dinitrogenase reductase from the cyanobacterium Anabaena variabilis (ATCC 29413)

Characterization of gonidial zone of Cycas revoluta coralloid roots by means of microelectrodes

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