Abstract
Changes in the oxygen partial pressure of air over the range of 8 to 258 mm of Hg did not adversely affect the photosynthetic capacity of Chlorella pyrenoidosa. Gas exchange and growth measurements remained constant for 3-week periods and were similar to air controls (oxygen pressure of 160 mm of Hg). Oxygen partial pressures of 532 and 745 mm of Hg had an adverse effect on algal metabolism. Carbon dioxide consumption was 24% lower in the gas mixture containing oxygen at a pressure 532 mm of Hg than in the air control, and the growth rate was slightly reduced. Oxygen at a partial pressure of 745 mm of Hg decreased the photosynthetic rate 39% and the growth rate 37% over the corresponding rates in air. The lowered metabolic rates remained constant during 14 days of measurements, and the effect was reversible after this time. Substitution of helium or argon for the nitrogen in air had no effect on oxygen production, carbon dioxide consumption, or growth rate for 3-week periods. All measurements were made at a total pressure of 760 mm of Hg, and all gas mixtures were enriched with 2% carbon dioxide. Thus, the physiological functioning and reliability of a photosynthetic gas exchanger should not be adversely affected by: (i) oxygen partial pressures ranging from 8 to 258 mm of Hg; (ii) the use of pure oxygen at reduced total pressure (155 to 258 mm of Hg) unless pressure per se affects photosynthesis, or (iii) the inclusion of helium or argon in the gas environment (up to a partial pressure of 595 mm of Hg).
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Selected References
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- AMMANN E. C., LYNCH V. H. GAS EXCHANGE OF ALGAE. I. EFFECTS OF TIME, LIGHT INTENSITY, AND SPECTRAL-ENERGY DISTRIBUTION ON THE PHOTOSYNTHETIC QUOTIENT OF CHLORELLA PYRENOIDOSA. Appl Microbiol. 1965 Jul;13:546–551. doi: 10.1128/am.13.4.546-551.1965. [DOI] [PMC free article] [PubMed] [Google Scholar]
- COOK S. F., SOUTH F. E., Jr, YOUNG D. R. Effect of helium on gas exchange of mice. Am J Physiol. 1951 Jan;164(1):248–250. doi: 10.1152/ajplegacy.1950.164.1.248. [DOI] [PubMed] [Google Scholar]
- COOK S. F. The effect of helium and argon on metabolism and metamorphosis. J Cell Physiol. 1950 Aug;36(1):115–127. doi: 10.1002/jcp.1030360109. [DOI] [PubMed] [Google Scholar]
- LEON H. A., COOK S. F. A mechanism by which helium increases metabolism in small mammals. Am J Physiol. 1960 Aug;199:243–245. doi: 10.1152/ajplegacy.1960.199.2.243. [DOI] [PubMed] [Google Scholar]
- Schreiner H. R., Gregoire R. C., Lawrie J. A. New Biological Effect of the Gases of the Helium Group. Science. 1962 May 18;136(3516):653–654. doi: 10.1126/science.136.3516.653. [DOI] [PubMed] [Google Scholar]
- WEISS H. S., WRIGHT R. A., HIATT E. P. EMBRYO DEVELOPMENT AND CHICK GROWTH IN A HELIUM-OXYGEN ATMOSPHERE. Aerosp Med. 1965 Mar;36:201–206. [PubMed] [Google Scholar]
- WRIGHT R. A., LESSLER M. A., WEISS H. S., HIATT E. P. METABOLISM AND X-RAY SENSITIVITY OF CHICK EMBRYOS INCUBATED IN A HELIUM-OXYGEN ATMOSPHERE. Aerosp Med. 1965 Apr;36:311–314. [PubMed] [Google Scholar]