[17] Inclusions: Granules of polyglucose, polyphosphate, and poly-β-hydroxybutyrate

Shively, Jessup

doi:10.1016/0076-6879(88)67020-0

Cited by 24 publications

(18 citation statements)

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“…During balanced photoautotrophic growth, glycogen was the only carbon storage compound detected, its intracellular concentration being close to that generally reported for cyanobacteria growing under similar conditions (Smith, 1982;Allen, 1984;Shively, 1988). The absence of PHB was surprising because its presence, even at a very low concentration, had seemed to be a constant feature of photoautotrophically grown Spirutina species (Vincenzini et al, 1990).…”

Section: Discussionmentioning

confidence: 88%

“…The major carbon-and energy-reserve compound accumulated by cyanobacteria during photoautotrophic growth is generally a glycogen-like polyglucan (Smith, 1982;Allen, 1984;Jensen, 1985;Shively, 1988). This polymer is massively accumulated in cyanobacterial cells whenever balanced growth is hampered by a particular nutrient deficiency (Allen & Smith, 1969;Lehmann & Wober, 1976;van Eykelenburg, 1980;Stevens et al, 1981) or by sudden increases in energy input (Ernst & Boger, 1985;Post, 1987).…”

Section: Introductionmentioning

confidence: 99%

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Glycogen and poly- -hydroxybutyrate synthesis in Spirulina maxima

Philippis¹,

Chen²,

Vincenzini³

1992

Journal of General Microbiology

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The effect of different growth conditions on the glycogen and poly-/I-hydroxybutyrate (PHB) content of the cyanobacterium Spirulina maxima is described. Under photoautotrophic growth conditions without any nutrient limitation, S. maxima exhibited a glycogen content of between 7-1 and 10.7% of cell dry wt, whereas PHB was undetectable. When S. maxima was grown under mixotrophic conditions in the presence of acetate, the intracellular PHB concentration increased to more than 3 % of dry wt, while glycogen content remained within the range of 5 to 6% of cell dry wt. Nitrogen starvation favoured glycogen accumulation (up to 60 to 70% of dry wt), while the PHB content remained low (up to 0.7% of dry wt), even after prolonged nitrogen starvation. Inhibition of protein synthesis, induced by addition of azaserine, led to the accumulation of glycogen (up to 52 yo of cell dry wt) but did not stimulate PHB synthesis. Under phosphorus-limited growth conditions, glycogen and PHB accumulated (up to 23% and 1.2% of cell dry wt, respectively) only after the exhaustion of intracellular phosphorus reserves. Shifting the culture from low to high light irradiance induced a rapid accumulation of glycogen (up to 34% of cell dry wt after 9 h) but did not induce PHB synthesis. Results are discussed in terms of the metabolic significance of PHB synthesis in cyanobacteria, and suggest that this polymer acts exclusively as a disposal mechanism to eliminate excess reducing equivalents.

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Section: Discussionmentioning

confidence: 88%

Section: Introductionmentioning

confidence: 99%

Glycogen and poly- -hydroxybutyrate synthesis in Spirulina maxima

Philippis¹,

Chen²,

Vincenzini³

1992

Journal of General Microbiology

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“…However, the former organisms synthesize glycogen as the major carbohydrate reserve (29), in a similar manner to what is observed in bacteria. The evolutionary relationship of cyanobacteria to prokaryotes and higher plants prompted a comparison of cyanobacterial ADPglucose pyrophosphorylase properties to those ofE.…”

mentioning

confidence: 87%

Regulatory and Structural Properties of the Cyanobacterial ADPglucose Pyrophosphorylases

Iglesias¹,

Kakefuda²,

Preiss³

1991

Plant Physiol.

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ADPglucose pyrophosphorylase (EC 2.7.7.27) has been purified from two cyanobacteria: the filamentous, heterocystic, Anabaena PCC 7120 and the unicellular Synechocystis PCC 6803.The purification procedure gave highly purified enzymes from both cynobacteria with specific activities of 134 (Synechocystis) and 111 (Anabaena) units per milligram protein. The purified enzymes migrated as a single protein band in sodium dodecyl sulfate-polyacrylamide gel electrophoresis with molecular mass corresponding to 53 (Synechocystis) and 50 (Anabaena) kilodaltons. Tetrameric structures were determined for the native enzymes by analysis of gel filtrations. Kinetic and regulatory properties were characterized for the cyanobacterial ADPglucose pyrophosphorylases. Inorganic phosphate and 3-phosphoglycerate were the most potent inhibitor and activator, respectively. The Synechocystis enzyme was activated 126-fold by 3-phosphoglycerate, with saturation curves exhibiting sigmoidicity (Ao.s = 0.81 millimolar; nH = 2.0). Activation by 3-phosphoglycerate of the enzyme from Anabaena demonstrated hyperbolic kinetics (Ao.5 = 0.12 millimolar, n,H = 1.0), having a maximal stimulation of 17-fold. 10.5 values of 95 and 44 micromolar were calculated for the inhibition by inorganic phosphate of the Synechocystis and Anabaena enzyme, respectively. Pyridoxal-phosphate behaved as an activator of the cyanobacterial enzyme. It activated the enzyme from Synechocystis nearly 10-fold with high apparent affinity (Ao.5 = 10 micromolar; n,H = 1.8). Phenylglyoxal modified the cyanobacterial enzyme by inactivating the activity in the presence of 3-phosphoglycerate. Antibody neutralization experiments showed that anti-spinach leaf (but not anti-Escherichia co/i) ADPglucose pyrophosphorylase serum inactivated the enzyme from cyanobacteria. When the cyanobacterial enzymes were resolved on sodium dodecyl sulfate-and two-dimensional polyacrylamide gel electrophoresis and probed with Westem blots, only one protein band was recognized by the anti-spinach leaf serum. The same polypeptide strongly reacted with antiserum prepared against the smaller spinach leaf 51 kilodalton subunit, whereas the anti-54 kilodalton antibody raised against the spinach subunit reacted weakly to the cyanobacterial subunit. Regulatory and immunological properties of the cyanobacterial enzyme are more related to the higher plant than the bacterial enzyme. Despite this, results suggest that the ADPglucose pyrophosphorylase from cyanobacteria is homotetrameric in structure, in contrast to the reported heterotetrameric structures of the higher plant ADPglucose pyrophosphorylase.

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“…Photosynthetic carbon assimilation in cyanobacteria results in the accumulation of polysaccharides, mostly glycogen (22), which is synthesized by the sequential actions of ADP-glucose pyrophosphorylase (AGPase, EC 2.7.7.27), glycogen synthase (GS, EC 2.4.1.21), and branching enzyme (BE, EC 2.4.1.18) (28). Although the accumulation of storage polysaccharides as intracellular inclusions has been extensively described (32,33), its physiological significance has not been thoroughly investigated.…”

mentioning

confidence: 99%

Carbohydrate Metabolism in Mutants of the Cyanobacterium Synechococcus elongatus PCC 7942 Defective in Glycogen Synthesis

Suzuki¹,

Ohkawa

Moriya³

et al. 2010

Appl Environ Microbiol

105

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ADP-glucose pyrophosphorylase (AGPase) and glycogen synthase (GS) catalyze the first two reactions of glycogen synthesis in cyanobacteria. Mutants defective in each of these enzymes in Synechococcus elongatus PCC 7942 were constructed and characterized. Activities of the corresponding enzymes in the selected mutants were virtually undetectable, and their ability to synthesize glycogen was entirely abolished. The maximal activities of photosynthetic O 2 evolution and the rates of respiration in the dark were significantly decreased in the mutants compared to those in wild-type cells. Addition of 0.2 M NaCl or 3 mM H 2 O 2 to liquid cultures markedly inhibited the growth of the AGPase and GS mutants, while the same treatment had only marginal effects on the wild type. These results suggest a significant role for storage polysaccharides in tolerance to salt or oxidative stress.

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[17] Inclusions: Granules of polyglucose, polyphosphate, and poly-β-hydroxybutyrate

Cited by 24 publications

References 57 publications

Glycogen and poly- -hydroxybutyrate synthesis in Spirulina maxima

Glycogen and poly- -hydroxybutyrate synthesis in Spirulina maxima

Regulatory and Structural Properties of the Cyanobacterial ADPglucose Pyrophosphorylases

Carbohydrate Metabolism in Mutants of the Cyanobacterium Synechococcus elongatus PCC 7942 Defective in Glycogen Synthesis

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