Determination of intracellular nitrate

Romero, Javier; Lara, Catalina; Guerrero, Miguel G.

doi:10.1042/bj2590545

Cited by 33 publications

(21 citation statements)

References 18 publications

(24 reference statements)

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“…Elemental analysis of washed and dried samples was performed with a Carlo Erba Strumentazione model 1106/R analyzer. Nitrate concentration in the medium was determined in the supernatant resulting from centrifugation of the cell suspension (3,000g, 5 min), using HPLC-chromatography as described by Romero et al (1989).…”

Section: Analytical Proceduresmentioning

confidence: 99%

Efficient one‐step production of astaxanthin by the microalga Haematococcus pluvialis in continuous culture

Río

Acién

García-Malea

et al. 2005

Biotech & Bioengineering

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The performance of Haematococcus pluvialis in continuous photoautotrophic culture has been analyzed, especially from the viewpoint of astaxanthin production. To this end, chemostat cultures of Haematococcus pluvialis were carried out at constant light irradiance, 1,220 μE/m2 · s, and dilution rate, 0.9/d, but varying the nitrate concentration in the feed medium reaching the reactor, from 1.7 to 20.7 mM. Both growth and biomass composition were affected by the nitrate supply. With saturating nitrate, the biomass productivity was high, 1.2 g/L · d, but astaxanthin accumulation did not take place, the C/N ratio of the biomass being 5.7. Under moderate nitrate limitation, biomass productivity was decreased, as also did biomass concentration at steady state, whereas accumulation of astaxanthin developed and the C/N ratio of the biomass increased markedly. Astaxanthin accumulation took place in cells growing and dividing actively, and its extent was enhanced in response to the limitation in nitrate availability, with a recorded maximum for astaxanthin cellular level of 0.8% of dry biomass and of 5.6 mg/L · d for astaxanthin productivity. The viability of a significant continued generation of astaxanthin‐rich H. pluvialis cells becomes thus demonstrated, as also does the continuous culture option as an alternative to current procedures for the production of astaxanthin using this microalga. The intensive variable controlling the behavior of the system has been identified as the specific nitrate input, and a mathematical model developed that links growth rate with both irradiance and specific nitrate input. Moreover, a second model for astaxanthin accumulation, also as a function of irradiance and specific nitrate input, was derived. The latter model takes into account that accumulation of astaxanthin is only partially linked to growth, being besides inhibited by excess nitrate. Simulations performed fit experimental data and emphasize the contention that astaxanthin can be efficiently produced under continuous mode by adjustment of the specific nitrate input, predicting even higher values for astaxanthin productivity. The developed models represent a powerful tool for management of such an astaxanthin‐generating continuous process, and could allow the development of improved systems for the production of astaxanthin‐rich Haematococcus cells. © 2005 Wiley Periodicals, Inc.

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Section: Analytical Proceduresmentioning

confidence: 99%

Efficient one‐step production of astaxanthin by the microalga Haematococcus pluvialis in continuous culture

Río

Acién

García-Malea

et al. 2005

Biotech & Bioengineering

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“…Ion-exchange high-performance liquid chromatography was used to analyze nitrite/nitrate (NOx) levels as initially described by Romero et al 20 cGMP levels were measured in the LAD by standard radioimmunoassay as previously described. 18 (2), the first diagonal branch of the LAD artery (3), and the great cardiac vein (6).…”

Section: Measurement Of Nitrite/nitrate and Cgmpmentioning

confidence: 99%

Nonanticoagulant Heparin Prevents Coronary Endothelial Dysfunction After Brief Ischemia-Reperfusion Injury in the Dog

et al. 1999

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“…Nitrate was detected at 210 nm using a Waters 2996 photodiode‐array detector (Waters, Mildford, MA, USA). For nitrate quantification of the samples, a calibration curve with known nitrate concentrations was previously performed (Romero et al. 1989).…”

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confidence: 99%

ISOLATION AND CHARACTERIZATION OF A LYCOPENE β‐CYCLASE GENE FROM THE ASTAXANTHIN‐PRODUCING GREEN ALGA CHLORELLA ZOFINGIENSIS (CHLOROPHYTA)¹

Cordero

Obraztsova

Martín

et al. 2010

Journal of Phycology

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The isolation, characterization, and regulation by light and nitrogen of the lycopene b-cyclase gene from Chlorella zofingiensis Dönz (CzlcyB), involved in the biosynthesis of astaxanthin and lutein, have been performed in this work. These carotenoids are of high commercial value as dyes in food and as nutraceuticals. The open reading frame (ORF) of CzlcyB encoded a polypeptide of 546 amino acids. A single copy of CzlcyB has been found in C. zofingiensis. The chararacteristic Rossmann or dinucleotide binding fold, present in most lycopene cyclases, has been also identified in the LCYb of C. zofingiensis (CzLCYb). Heterologous genetic complementation in Escherichia coli showed the ability of the predicted protein to cycle both lycopene and d-carotene. Phylogenetic analysis has shown that the deduced protein forms a cluster with the rest of the lycopene b-cyclases (LCYb) of the chlorophycean microalgae studied, being very closely related to LCYb of plants. Transcript levels of CzlcyB were increased under nitrogen deprivation, but no increase was observed under high-light conditions. However, high irradiance triggered astaxanthin synthesis, while nitrogen deprivation by itself could not induce it. The combination of high irradiance and nitrogen deprivation led to a significant enhancement of the astaxathin accumulation.

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Determination of intracellular nitrate

Cited by 33 publications

References 18 publications

Efficient one‐step production of astaxanthin by the microalga Haematococcus pluvialis in continuous culture

Efficient one‐step production of astaxanthin by the microalga Haematococcus pluvialis in continuous culture

Nonanticoagulant Heparin Prevents Coronary Endothelial Dysfunction After Brief Ischemia-Reperfusion Injury in the Dog

ISOLATION AND CHARACTERIZATION OF A LYCOPENE β‐CYCLASE GENE FROM THE ASTAXANTHIN‐PRODUCING GREEN ALGA CHLORELLA ZOFINGIENSIS (CHLOROPHYTA)¹

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Determination of intracellular nitrate

Cited by 33 publications

References 18 publications

Efficient one‐step production of astaxanthin by the microalga Haematococcus pluvialis in continuous culture

Efficient one‐step production of astaxanthin by the microalga Haematococcus pluvialis in continuous culture

Nonanticoagulant Heparin Prevents Coronary Endothelial Dysfunction After Brief Ischemia-Reperfusion Injury in the Dog

ISOLATION AND CHARACTERIZATION OF A LYCOPENE β‐CYCLASE GENE FROM THE ASTAXANTHIN‐PRODUCING GREEN ALGA CHLORELLA ZOFINGIENSIS (CHLOROPHYTA)1

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ISOLATION AND CHARACTERIZATION OF A LYCOPENE β‐CYCLASE GENE FROM THE ASTAXANTHIN‐PRODUCING GREEN ALGA CHLORELLA ZOFINGIENSIS (CHLOROPHYTA)¹