Abstract
The rates of inorganic carbon accumulation and carbon fixation in light by the unicellular cyanobacterim Coccohloris peniocystis have been determined. Cells incubated in the light in medium containing H14CO3- were rapidly separated from the medium by centrifugation through silicone oil into a strongly basic terminating solution. Samples of these inactivated cells were assayed to determine total 14C accumulation, and acid-treated samples were assayed to determine 14C fixation. The rate of transport of inorganic into illuminated cells was faster than the rate of CO2 production in the medium from HCO3- dehydration. This evidence for HCO3- transport in these cells is in agreement with our previous results based upon measurements of photosynthetic O2 evolution. A substantial pool of inorganic carbon was bulit up within the cells presumably as HCO3- before the onset of the maximum rate of photosynthesis. Large accumulation ratios were observed, greater than 1,000 times the external HCO3- concentration. Accumulation did not occur in the dark and was greatly suppressed by the photosynthesis inhibitors 3-(3,4-dichlorophenyl)-1,1-dimethyl urea and 3-chloro-carbonylcyanide phenylhydrazone. These results indicate that the accumulation of inorganic carbon in these cells involves a light-dependent active transport process.
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Selected References
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- Birmingham B. C., Colman B. Measurement of carbon dioxide compensation points of freshwater algae. Plant Physiol. 1979 Nov;64(5):892–895. doi: 10.1104/pp.64.5.892. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Coleman J. R., Colman B. Effect of oxygen and temperature on the efficiency of photosynthetic carbon assimilation in two microscopic algae. Plant Physiol. 1980 May;65(5):980–983. doi: 10.1104/pp.65.5.980. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Gaensslen R. E., McCarty R. E. Determination of solute accumulation in chloroplasts by rapid centrifugal transfer through silicone fluid layers. Anal Biochem. 1972 Aug;48(2):504–514. doi: 10.1016/0003-2697(72)90105-4. [DOI] [PubMed] [Google Scholar]
- Miller A. G., Colman B. Evidence for HCO(3) Transport by the Blue-Green Alga (Cyanobacterium) Coccochloris peniocystis. Plant Physiol. 1980 Feb;65(2):397–402. doi: 10.1104/pp.65.2.397. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Paschinger H. DCCD induced sodium uptake by Anacystis nidulans. Arch Microbiol. 1977 Jun 20;113(3):285–291. doi: 10.1007/BF00492037. [DOI] [PubMed] [Google Scholar]
- Stanier R. Y., Kunisawa R., Mandel M., Cohen-Bazire G. Purification and properties of unicellular blue-green algae (order Chroococcales). Bacteriol Rev. 1971 Jun;35(2):171–205. doi: 10.1128/br.35.2.171-205.1971. [DOI] [PMC free article] [PubMed] [Google Scholar]