Effects of light, salinity and nutrient limitation on the production of β-1,3-d-glucan and exo-d-glucanase activity in Skeletonema costatum (Grev.) Cleve

Vårum, Kjell M.; Myklestad, Sverre

doi:10.1016/0022-0981(84)90114-x

Cited by 47 publications

(40 citation statements)

References 19 publications

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“…It was shown that C. closterium cells were stimulated to increase production of the nominal 'exopolysaccharide' in the first 5 days after being transferred to the NH 4 + -limited medium. These results are congruent with previous reports that nitrogen limitation emulated the effects of the onset of stationary phase and resulted in chrysolaminaran accumulation in S. costatum (Va˚rum & Myklestad, 1984;Myklestad, 1988Myklestad, /1989Granum & Myklestad, 2001). Supplementing nitrogen-depleted S. costatum with NH 4 + in the dark resulted in the immediate activation of amino acid synthesis at the expense of chrysolaminaran (Granum & Myklestad, 1999).…”

Section: Discussionsupporting

confidence: 92%

“…A role for chrysolaminaran in nitrogen metabolism also has been demonstrated. Chrysolaminaran accumulated in S. costatum grown in nitrogen-depleted media and, when the media were supplemented with ammonium or nitrate, the amino acid pool increased with concomitant depletion of chrysolaminaran (Va˚rum & Myklestad, 1984;Granum & Myklestad, 1999. The degradation of chrysolaminaran released glucose, which was used to supply carbon skeletons for the synthesis of amino acids (Granum & Myklestad, 2001).…”

mentioning

confidence: 99%

“…The methods used to extract diatom chrysolaminaran generally involved cell disruption by treatment with dilute H 2 SO 4 (Myklestad & Haug, 1972;Va˚rum & Myklestad, 1984;Va˚rum et al, 1986;Granum & Myklestad, 1999 or extensive extraction with water at or near boiling temperature (Handa, 1969;Handa & Tominaga, 1969;Handa & Yanagi, 1969;Hama & Handa, 1992;Wustman et al, 1997). Cell disruption was often assisted by lyophilization of the diatoms or, in the study of chrysolaminaran from P. tricornutum, by pulverizing frozen cells (Ford & Percival, 1965).…”

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confidence: 99%

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The glucans extracted with warm water from diatoms are mainly derived from intracellular chrysolaminaran and not extracellular polysaccharides

Chiovitti

Molino

Crawford

et al. 2004

European Journal of Phycology

104

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Several recent studies have employed warm-water treatment of diatom cells to extract nominally bound extracellular polymeric substances. Where examined, the dominant neutral sugar in these extracts was glucose. In the present study, we sought to characterize the structure of the glucose-rich polymers in the water extracts of diatoms and to determine the origin of these polymers. The marine diatoms surveyed were Phaeodactylum tricornutum, Cylindrotheca fusiformis, Craspedostauros australis and Thalassiosira pseudonana. A freshwater species, Pinnularia viridis, was also investigated for the dye labelling experiments. Freshly harvested marine diatoms were extracted with water at 308C for 1 h. Constituent monosaccharide analyses showed that glucose was the dominant neutral sugar (80 -95 mol% of the total) in the extracts from three marine species, whereas the P. tricornutum extract contained predominantly ribose, galactose and glucose, and was inferred to be enriched in low-molecular-weight components. Linkage analysis of the constituent monosaccharides and proton nuclear magnetic resonance spectroscopy showed that the glucose in these extracts was derived primarily from 1,3-b-D-glucan. Immunocytochemistry with a monoclonal anti-1,3-b-D-glucan antibody confirmed that the glucan was localized in the vacuoles of diatom cells preserved by freeze-substitution. Nearly all diatom cells incubated with a fluorescent dye, DiBAC 4 (3), during warm water treatment at 308C or 608C incorporated the dye, demonstrating that the membrane integrity of the diatoms was compromised and supporting the contention that intracellular glucan was released during the treatment. In light of these data, the extracellular glucans of diatoms reported in some previous studies are re-interpreted as intracellular chrysolaminaran.

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Section: Discussionsupporting

confidence: 92%

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confidence: 99%

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confidence: 99%

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The glucans extracted with warm water from diatoms are mainly derived from intracellular chrysolaminaran and not extracellular polysaccharides

Chiovitti

Molino

Crawford

et al. 2004

European Journal of Phycology

104

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“…Moreover, the cells accumulated excessive N pools in the photophase to buffer the effect of low NO 3 -uptake and reduction in darkness. Protein synthesis in the dark using glucan reserves has been indicated by several investigations (Cuhel et al 1984, Vårum & Myklestad 1984, Granum & Myklestad 1999. This is probably an important strategy for algae to optimize growth under diel light conditions.…”

Section: Cellular Productionmentioning

confidence: 99%

“…The cellular glucan content accumulates markedly under nutrient deficiency (Myklestad & Haug 1972, Myklestad 1974). The glucan is consumed by the alga when kept in the dark, and apparently serves as a respiratory substrate (Handa 1969, Vårum & Myklestad 1984.…”

Section: Introductionmentioning

confidence: 99%

Cellular and extracellular production of carbohydrates and amino acids by the marine diatom Skeletonema costatum: diel variations and effects of N depletion

Granum

Kirkvold²,

Myklestad³

2002

Mar. Ecol. Prog. Ser.

224

167

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A detailed study was made of cellular and extracellular production of carbohydrates and amino acids by the marine diatom Skeletonema costatum (Grev.) Cleve during different growth phases. Batch cultures were run with a 14:10 h light:dark cycle in N-limited media at 2 different nutrient strengths. The exponential growth rate was 2.0 div. d -1, and balanced growth took place except for significant diel variation in chemical composition. Inorganic C and N were primarily assimilated during the photophase, and the elemental cell quotas increased accordingly. The level of storage polysaccharide, β-1, 3-glucan, oscillated between 17% (end of scotophase) and 42% (end of photophase) of cellular organic C, and the corresponding protein:glucan ratio alternated between 2.3 and 0.7. Cell wall polysaccharides constituted 6 to 10% of cellular organic C. Concurrently, the cellular free amino acid pool oscillated between 8% (end of scotophase) and 22% (end of photophase) of cellular organic N. Glutamine emerged as the principal amino acid during photosynthesis, increasing from 0.2 to 12 fmol cell -1 , and the corresponding glutamine:glutamate ratio increased from 0.05 to 2. Upon NO 3 -exhaustion, the glucan level increased rapidly for 3 to 4 d, and then stabilized at 75 to 80% of cellular organic C with little diel variation. In contrast, the cellular N quota decreased by 80%, and the cell wall polysaccharide quota decreased by 35%. Consequently, the protein:glucan ratio decreased to < 0.1. The cellular free amino acid pool decreased by 90% within 24 h of N depletion, and continued to decrease slowly throughout the stationary phase. Glutamine decreased most rapidly, and constituted <1% of the free amino acids in the stationary phase. Extracellular production accounted for 4% of total photosynthetic production during both exponential and stationary growth phase, but the absolute excretion rate (per cell) was markedly higher in the exponential phase. A transient high release occurred in the transition phase in 1 case, which was probably caused by cell leakage. Extracellular production by 'healthy' cells contained 33% polysaccharides, 15% monosaccharides and 5% free amino acids (as C). The composition of the extracellular amino acids differed from the intracellular ones, and changed considerably from exponential to stationary growth phase. This study illustrates the rapid response of carbohydrate and amino acid dynamics to ambient N and light conditions at the cellular level.

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Overview of flow cytometry and image analysis in biological oceanography and limnology

Legendre

Yentsch

1989

Cytometry

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Effects of light, salinity and nutrient limitation on the production of β-1,3-d-glucan and exo-d-glucanase activity in Skeletonema costatum (Grev.) Cleve

Cited by 47 publications

References 19 publications

The glucans extracted with warm water from diatoms are mainly derived from intracellular chrysolaminaran and not extracellular polysaccharides

The glucans extracted with warm water from diatoms are mainly derived from intracellular chrysolaminaran and not extracellular polysaccharides

Cellular and extracellular production of carbohydrates and amino acids by the marine diatom Skeletonema costatum: diel variations and effects of N depletion

Overview of flow cytometry and image analysis in biological oceanography and limnology

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