Regulation of nitrate reductase levels in the cyanobacteria Anacystis nidulans, Anabaena sp. strain 7119, and Nostoc sp. strain 6719

Herrero, Antonia; Flores, Enrique; Guerrero, Miguel G.

doi:10.1128/jb.145.1.175-180.1981

Cited by 192 publications

(47 citation statements)

References 19 publications

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“…A passive diffusion of nitrous acid, insensitive to ammonium, would, in addition, contribute to nitrite uptake [253,[255][256][257][258][259]. In unicellular non-nitrogen-tiLting strains, the regulation of the activity levels of the nitrate reducing system, nitrate and nitrite reductases, proceeds mainly through a repression promoted by ammonium, which needs to be metabolized through glutamine synthetase to be effective [253,[260][261][262]. Nitrate and nitrite may also have secondary roles in the induction of the enzyme levels in Synechococcus PCC 6301 [261,263].…”

Section: Nitrate and Nitrite Utilizationmentioning

confidence: 99%

“…Nitrate and nitrite may also have secondary roles in the induction of the enzyme levels in Synechococcus PCC 6301 [261,263]. In filamentous strains fixing nitrogen, the regulation is exerted through a combined process involving both induction by nitrate or nitrite and repression by ammonium itself [264,265] or more likely via products of its assimilation [253][254][255]260,262].…”

Section: Nitrate and Nitrite Utilizationmentioning

confidence: 99%

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Adaptation of cyanobacteria to environmental stimuli: new steps towards molecular mechanisms

Marsac

Houmard

1993

FEMS Microbiology Letters

375

128

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Dating from the Pre‐Cambrian era, cyanobacteria have a long history of adaptation to the Earth's environment. By evolving oxygen via photosynthetic reactions similar to those of plants and green algae, these prokaryotes were essential to the evolution of the present biosphere. They continue to make a large contribution to the equilibrium of the Earth's atmosphere by production oxygen and removing carbon dioxide. To survive in extreme or variable environments, cyanobacteria have developed specific regulatory systems, in addition to more general mechanisms equivalent to those of other prokaryotes or photosynthesis eukaryotes. Specific regulatory systems control the differentiation of specialized nitrogen‐fixing cells and of cell types facilitating the dispersion of species. In the past decade, considerable progress has been made towards understanding the expression of the cyanobacterial genome in response to variations in the intensity and spectral quality of incident light and in response to nutritional conditions, especially carbon, nitrogen and sulphur sources. These studies have provided insights into the relationships between carbon and nitrogen intermediary metabolism, and a start towards understanding of the interconnected pathways which lead from the perception of environmental signals to the regulation of enzyme activities and gene expression. Cyanobacterial regulatory mechanisms share common features with those of other prokaryotes, but are unique since these essentially photo‐autotrophic organisms must maintain a proper cellular C/N balance, in spite of dailty variations in incident light. Thus an appropriate coordination between photosynthesis and other metabolic processes must be achieved through control of the catalytic activity of key enzymes by reducing equivalents and ATP produced by photosynthetic or respiratory electron transport. Recently discovered kinases/phosphatases act by post‐translational modification of specific proteins which probably act as signal transducers or modulators of gene expression in a manner similar to the well‐known two‐component regulatory systems described in other bacteria. In this overview, we present our current knowledge on the molecular aspects of the biology of cyanobacteria, as well as on their mechanisms of resistance to metal ions and their responses to metabolic stress.

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Section: Nitrate and Nitrite Utilizationmentioning

confidence: 99%

Section: Nitrate and Nitrite Utilizationmentioning

confidence: 99%

Adaptation of cyanobacteria to environmental stimuli: new steps towards molecular mechanisms

Marsac

Houmard

1993

FEMS Microbiology Letters

375

128

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“…Nitrate reductase activity can be readily determined and represents a convenient marker for proteins subjected to nitrogen control in Synechococcus sp. [10]. Repression by ammonium of nitrate reductase is relieved by the glutamine synthetase inhibitor L-methionine-D,L-sulfoximine (MSX [10]).…”

Section: Introductionmentioning

confidence: 99%

“…[10]. Repression by ammonium of nitrate reductase is relieved by the glutamine synthetase inhibitor L-methionine-D,L-sulfoximine (MSX [10]). This observation led to the conclusion that ammonium has to be incorporated into carbon skeletons to exert its repressor role in Synechococcus sp.…”

Section: Introductionmentioning

confidence: 99%

Carbon supply and 2-oxoglutarate effects on expression of nitrate reductase and nitrogen-regulated genes inSynechococcussp. strain PCC 7942

Vázquez-Bermúdez¹,

Herrero

Flores

2003

FEMS Microbiology Letters

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Synthesis of nitrate reductase in the unicellular cyanobacterium Synechococcus sp. strain PCC 7942 took place at a slow rate when the cells were incubated without a supply of inorganic carbon, but addition to these cells of CO(2)/bicarbonate or, in a Synechococcus strain transformed with a gene encoding a 2-oxoglutarate permease, 2-oxoglutarate stimulated expression of the enzyme. Induction by 2-oxoglutarate was also observed at the mRNA level for two nitrogen-regulated genes, nir and amt1, but not for the photosystem II D1 protein-encoding gene psbA1. Our results are consistent with a role of 2-oxoglutarate in nitrogen control in cyanobacteria.

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“…Dissolved oxygen (DO) was monitored using an Oxymeter (Toshniwal Instruments, New Delhi). Nitrate reductase and glutamine synthetase assays of washed, fresh, and wet biomass were performed according to Herrero et al (1981) and Shapiro and Stadman (19701, respectively. Net OPR Measurements. The culture was diluted to 0.2 OD with nutrient medium.…”

Section: Methodsmentioning

confidence: 99%

Eucalyptus Kraft Black Liquor Enhances Growth and Productivity of Spirulina in Outdoor Cultures

Chauhan

Singh

Ramamurthy

1995

Biotechnology Progress

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Mass cultivation of microalgae for commercial applications suffers from poor productivities when measured against laboratory results or theoretical projections. In an effort to reduce this gap it was discovered that addition of eucalyptus kraft black liquor (BL) enhanced biomass productivity in outdoor cultures of Spirulina by increasing growth rate by 38% and biomass yield by 43%. BL treatment resulted in elevation of nitrogen assimilating enzyme activities and efficiency of phosphate utilization. Analyses of forenoon and afternoon oxygen production rates (OPRs) indicated higher photosynthetic and respiratory activity in BL‐treated cultures compared to untreated cultures.

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Regulation of nitrate reductase levels in the cyanobacteria Anacystis nidulans, Anabaena sp. strain 7119, and Nostoc sp. strain 6719

Cited by 192 publications

References 19 publications

Adaptation of cyanobacteria to environmental stimuli: new steps towards molecular mechanisms

Adaptation of cyanobacteria to environmental stimuli: new steps towards molecular mechanisms

Carbon supply and 2-oxoglutarate effects on expression of nitrate reductase and nitrogen-regulated genes inSynechococcussp. strain PCC 7942

Eucalyptus Kraft Black Liquor Enhances Growth and Productivity of Spirulina in Outdoor Cultures

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