Studies on Chlorella Vulgaris. Viii. Influence on Photosynthesis of Prolonged Exposure to Sodium Bicarbonate and Potassium Bicarbonate

Pratt, Robertson

doi:10.1002/j.1537-2197.1943.tb10310.x

Cited by 12 publications

(2 citation statements)

References 10 publications

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“…Experiments with increased [Na + ] in the HEPES buffer and identical experiments with a K + -Pbuffer (instead of the Na + -P-buffer), indicated that the combination of increased P i and Na + concentrations in combination with a high pH in particular, decreased quantum yield (Φ II,e ) of charge separation at PS2. As early as 1943, Pratt observed that the Na + salts of HCO 3 and CO 3 2inhibited growth of Chlorella vulgaris (Pratt 1943). This inhibition in C. vulgaris was later confirmed using 13 mM Na + , and was in their case not related to CO 2 availability or pH (Goldman and Graham 1981).…”

Section: Discussionmentioning

confidence: 98%

Negative Effects of P-Buffering and pH on Photosynthetic Activity of Planktonic Desmid Species

Spijkerman¹,

García‐Mendoza²,

Matthijs³

et al. 2004

Photosynt.

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The photosynthetic activities of three planktonic desmid species (Staurastrum brachiatum, Staurodesmus cuspidatus var. curvatus, and Staurastrum chaetoceras) were compared after adaptation to medium enriched with either a 20 mM Na +phosphate (P) or HEPES buffer. Incubations up to 2 d were carried out at pH 6 or 8 under normal air or air enriched with 5 % CO 2 . Gross maximum photosynthetic rate (P max ) and growth rate were decreased in both S. brachiatum and Std. cuspidatus at higher pH when using the HEPES buffer and this effect was independent of CO 2 concentration, indicating that pH had an inhibitory effect on photosynthesis and growth in these species. The P-buffer at pH 8 caused a large decrease in P max and quantum yield for charge separation in photosystem 2 (PS2), compared to HEPES-buffered algae. This effect was very large in both S. brachiatum and Std. cuspidatus, two species characteristic of soft water lakes, but also significant in S. chaetoceras, a species dominant in eutrophic, hard water lakes. The decreased P max in P-buffer could not be related to a significant increase in cellular P content known to be responsible for inhibition in isolated chloroplasts. Experiments at pH 6 and 8 showed that two conditions, high pH and high Na + concentration, both contributed to the decreased P max and quantum yield in the desmids. Effects of a P-buffer were less pronounced by using K + -P buffer. The use of P-buffer at pH 8 possibly resulted in high irradiance stress in all species, indicated by damage in the PS2 core complex. In the soft water species pH 8 resulted in increased non-photochemical quenching together with a high de-epoxidation state of the xanthophyll cycle pigments.

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Section: Discussionmentioning

confidence: 98%

Negative Effects of P-Buffering and pH on Photosynthetic Activity of Planktonic Desmid Species

Spijkerman¹,

García‐Mendoza²,

Matthijs³

et al. 2004

Photosynt.

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“…Respiration measurements were made in a dark room or with appropriate vessels covered with double-thickness black cotton bags; respiratory quotients were measured by the two-vessel direct method with the cells in water or phosphate buffer; values of carbon dioxide output were corrected for retention by the method of Johnson (in Umbreit, Burris, and Stauffer 1964). Warburg buffers as modified by Pratt (1943), or 0•067M phosphate buffers (Na+ and K+ salts), pH 6'7, served as the suspension medium. Dry weight determinations (24 hr at 80°C) were usually made on replicate control samples of the cultures used; sometimes it was necessary to use the experimental material itself for dry weight measurements at the end of an experiment.…”

Section: Methodsmentioning

confidence: 99%

The Effeots of the Dipyridyl Diquat on the Metabolism of Chlorella Vulgaris I. Gas Exchange in the Light

Turner¹,

Stokes²,

Gilmore³

1970

Aust. Jnl. Of Bio. Sci.

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The effects of diquat on gas exchange in illuminated C. vUlgaris have been studied by manometric procedures. Estimates of dark oxygen uptake were made by transfer of treated cells to darkness. Analysis of the results indicates that on adding diquat to C. vUlgariB there is a rapid fall in the rate of apparent photosynthesis. This is due to an immediate and large increase in dark metabolism (C02 and O2 exchange) accompanied by irreversible inhibition of real photosynthesis firstly, then of respiration. At some unspecified stage a light-dependent oxygen uptake begins, rises to a maximum rate, and declines to a low value, continuing after the inhibition of respiration. These results are discussed in relation to the known effects of diquat on plastid reactions and to the hypothesis that in illuminated green tissue diquat produces a toxic substance which damages both the photosynthetic and respiratory apparatus.

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Photosynthesis Relationships of Chlorella Species

Winokur

1948

American J of Botany

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Studies on Chlorella Vulgaris. Viii. Influence on Photosynthesis of Prolonged Exposure to Sodium Bicarbonate and Potassium Bicarbonate

Cited by 12 publications

References 10 publications

Negative Effects of P-Buffering and pH on Photosynthetic Activity of Planktonic Desmid Species

Negative Effects of P-Buffering and pH on Photosynthetic Activity of Planktonic Desmid Species

The Effeots of the Dipyridyl Diquat on the Metabolism of Chlorella Vulgaris I. Gas Exchange in the Light

Photosynthesis Relationships of Chlorella Species

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