Abstract
A comparison of the quantum yield spectra of the oxygenic (H2O as the electron donor) with the anoxygenic (H2S as the electron donor) photosynthesis of the cyanobacterium, Oscillatoria limnetica reveals that anoxygenic photosynthesis is driven by photosystem I only. The highest quantum yields of the latter (maximum; 0.059 CO2 molecules/quantum of absorbed light) were obtained with wavelengths which preferentially excite photosystem I (<550, >650) in which chlorophyll a and carotenoids are the major pigments. The addition of 3-(3,4-dichlorophenyl)-1,1-dimethylurea had no effect on anoxygenic photosynthesis, and no enhancement in quantum efficiency was observed by a superimposition of light preferentially exciting photosystem II.
Oxygenic photosynthesis efficiently utilizes only a narrow range of the absorption spectrum (550-650 nm) where light is provided in excess to photosystem II via phycocyanin. The quantum yield (0.033 CO2 molecules/quantum of absorbed light) is lower than the theoretical yield by a factor of 3, possibly due to inefficient light transfer from photosystem II to I. Thus, 3-fold enhancement of oxygenic photosynthesis by superimposition of photosystem I light, and low quantum yields for anoxygenic photosynthesis, were obtained in this region. These results are consonant with the suggestion that such a cyanobacterium represents an intermediate stage in phototrophic evolution.
Keywords: blue-green algae, photosystem I growth, phototrophic evolution, H2S photooxidation
Full text
PDF
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Avron M., Gibbs M. Properties of phosphoribulokinase of whole chloroplasts. Plant Physiol. 1974 Feb;53(2):136–139. doi: 10.1104/pp.53.2.136. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bishop N. I. Comparison of the action spectra and quantum requirements for photosynthesis and photo-reduction of Scenedesmus. Photochem Photobiol. 1967 Sep;6(9):621–628. doi: 10.1111/j.1751-1097.1967.tb08767.x. [DOI] [PubMed] [Google Scholar]
- Cohen Y., Padan E., Shilo M. Facultative anoxygenic photosynthesis in the cyanobacterium Oscillatoria limnetica. J Bacteriol. 1975 Sep;123(3):855–861. doi: 10.1128/jb.123.3.855-861.1975. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Govindjee R., Rabinowitch E., Govindjee Maximum quantum yield and action spectrum of photosynthesis and fluorescence in Chlorella. Biochim Biophys Acta. 1968 Nov 26;162(4):539–544. doi: 10.1016/0005-2728(68)90061-3. [DOI] [PubMed] [Google Scholar]
- Jones L. W., Myers J. Enhancement in the Blue-Green Alga, Anacystis nidulans. Plant Physiol. 1964 Nov;39(6):938–946. doi: 10.1104/pp.39.6.938. [DOI] [PMC free article] [PubMed] [Google Scholar]
- LOWRY O. H., ROSEBROUGH N. J., FARR A. L., RANDALL R. J. Protein measurement with the Folin phenol reagent. J Biol Chem. 1951 Nov;193(1):265–275. [PubMed] [Google Scholar]
- Lemasson C., Marsac N. T., Cohen-Bazire G. Role of allophycocyanin as light-harvesting pigment in cyanobacteria. Proc Natl Acad Sci U S A. 1973 Nov;70(11):3130–3133. doi: 10.1073/pnas.70.11.3130. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Malkin S. Theoretical analysis of the enhancement effect in photosynthesis evidence for the "spill-over" model. Biophys J. 2008 Dec 31;7(6):629–649. doi: 10.1016/S0006-3495(67)86613-X. [DOI] [PMC free article] [PubMed] [Google Scholar]
- SHIBATA K., BENSON A. A., CALVIN M. The absorption spectra of suspensions of living micro-organisms. Biochim Biophys Acta. 1954 Dec;15(4):461–470. doi: 10.1016/0006-3002(54)90002-5. [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]