Purification and characterization of glutamine synthetase from the green alga Monoraphidium braunii

García-Fernández, José Manuel; Lopez‐Ruiz, Arnaldo; Humanes, Lourdes; Dapena, Jesús Díez

doi:10.1016/s0168-9452(96)04580-3

Cited by 5 publications

(4 citation statements)

References 36 publications

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“…K m constants of the transferase and biosynthetic activities were calculated utilizing the Lineweaver–Burk plot method. As previously observed in other studies (García‐Fernández et al ., 1997), K m value for ADP could not be calculated for the transferase activity, since all tested concentrations produced similar results (not shown). The determined K m values for the rest of substrates were comparable to those described in other cyanobacteria (Table 2).…”

Section: Resultsmentioning

confidence: 99%

“…As previously observed in other studies M, molecular mass markers; A, crude extract after centrifugation; B, supernatant after ammonium sulphate precipitation; C, dialysed supernatant; D, mixture of fractions from the peak obtained by chromatography Q-Hyper D; E, fraction with maximum GS activity from the same activity peak. (García-Fernández et al ., 1997), K m value for ADP could not be calculated for the transferase activity, since all tested concentrations produced similar results (not shown). The determined K m values for the rest of substrates were comparable to those described in other cyanobacteria (Table 2).…”

Section: Characterization Of Purified Gs From Prochlorococcus Pcc 9511mentioning

confidence: 99%

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Glutamine synthetase from the marine cyanobacteria Prochlorococcus spp.: characterization, phylogeny and response to nutrient limitation

Alaoui

Dı́ez

Toribio

et al. 2003

Environmental Microbiology

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The regulation of glutamine synthetase (EC 6.3.1.2) from Prochlorococcus was previously shown to exhibit unusual features: it is not upregulated by nitrogen starvation and it is not inactivated by darkness (El Alaoui et al. (2001) Appl Environ Microbiol 67: 2202-2207). These are probably caused by adaptations to oligotrophic environments, as confirmed in this work by the marked decrease in the enzymatic activity when cultures were subjected to iron or phosphorus starvation. In order to further understand the adaptive features of ammonium assimilation in this cyanobacterium, glutamine synthetase was purified from two Prochlorococcus strains: PCC 9511 (high-light adapted) and SS120 (low-light adapted). We obtained approximately 100-fold purified samples of glutamine synthetase electrophoretically homogeneous, with a yield of approximately 30%. The estimated molecular mass of the subunits was roughly the same for both strains: 48.3 kDa. The apparent Km constants for the biosynthetic activity were 0.30 mM for ammonium, 1.29 mM for glutamate and 1.35 mM for ATP; the optimum pH was 8.0. Optimal temperature was surprisingly high (55 degrees C). Phylogenetic analysis of glnA from three Prochlorococcus strains (MED4, MIT9313 and SS120) showed they group closely with marine Synechococcus isolates, in good agreement with other studies based on 16 S RNA sequences. All of our results suggest that the structure and kinetics of glutamine synthetase in Prochlorococcus have not been significantly modified during the evolution within the cyanobacterial radiation, in sharp contrast with its regulatory properties.

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Section: Resultsmentioning

confidence: 99%

Section: Characterization Of Purified Gs From Prochlorococcus Pcc 9511mentioning

confidence: 99%

Glutamine synthetase from the marine cyanobacteria Prochlorococcus spp.: characterization, phylogeny and response to nutrient limitation

Alaoui

Dı́ez

Toribio

et al. 2003

Environmental Microbiology

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“…For GS transferase activity, cell-free extracts were prepared according to the methods of García-Ferná ndez et al (1997) and Humanes et al (1995) with a small modification. Duplicate samples were collected on the cellulose acetate membranes (Whatman, 0.45 mm) and broken up in 2.0 ml extraction buffer with 50 mmol l À 1 Tris-HCl buffer, pH 7.5; 2 mmol l…”

Section: Methodsmentioning

confidence: 99%

Response of phytoplankton to nitrogen addition in the Taiwan strait upwelling region: Nitrate reductase and glutamine synthetase activities

Hong

Wang

2011

Continental Shelf Research

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“…Research focuses on transport systems that are responsible for CO 2 and, in this context, nitrate uptake, as they play one of the most significant roles in biotechnology applications [26][27][28][29]. In addition, enzymes with different functions also reveal a lot of information about the function and physiology of microorganisms of similar structures [30][31][32][33][34]. An important area related to the use of Monoraphidium species is their sensitivity to metals, their possible role in bioindication, and/or bioremediation [35][36][37][38].…”

Section: Introductionmentioning

confidence: 99%

The Effects of Photobioreactor Type on Biomass and Lipid Production of the Green Microalga Monoraphidium pusillum in Laboratory Scale

et al. 2022

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Mass production of microorganisms, algae among them, for new bioactive compounds and renewable innovative products is a current issue in biotechnology. The greatest challenge of basic research on this topic is to find the best solution for both physiology and scalability. In this study, the main goal was to highlight the contradictions of physiological and technological optimization in the same, relatively small, laboratory scale. The green alga Monoraphidium pusillum (Printz) Komárková-Legnorová was cultured in a conventional Erlenmeyer flask (as air bubbled in a tank-type photobioreactor) and in a hybrid (fermenter type + helical tubular type) photobioreactor of the same volume (2.8 L). Higher cell numbers from 1.7–2.3-fold, 2–2.8-fold higher dry masses, and 1.9–2.6-fold higher total lipid contents (mg·L−1) were measured in the tank reactor than in the hybrid reactor. Cultures in the conventional tank reactor were characterized with better nutrient utilization (42.8–77.7% higher phosphate uptake) and more diverse lipid composition than in the hybrid reactor. The study highlights that well-scalable arrangements and settings could be not optimal (or unsuitable in some cases) from a physiological point of view. The results suggest certain developmental directions for complex, well-scalable devices and highlight the importance of testing the gained physiological optima on these systems.

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Purification and characterization of glutamine synthetase from the green alga Monoraphidium braunii

Cited by 5 publications

References 36 publications

Glutamine synthetase from the marine cyanobacteria Prochlorococcus spp.: characterization, phylogeny and response to nutrient limitation

Glutamine synthetase from the marine cyanobacteria Prochlorococcus spp.: characterization, phylogeny and response to nutrient limitation

Response of phytoplankton to nitrogen addition in the Taiwan strait upwelling region: Nitrate reductase and glutamine synthetase activities

The Effects of Photobioreactor Type on Biomass and Lipid Production of the Green Microalga Monoraphidium pusillum in Laboratory Scale

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