Quantum yields for oxygenic and anoxygenic photosynthesis in the cyanobacterium Oscillatoria limnetica.
Quantum yields for oxygenic and anoxygenic photosynthesis in the cyanobacterium Oscillatoria limnetica.
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蓝藻振荡藻的有氧和无氧光合作用的量子产率。
DOI：
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发表时间：
1977
影响因子：
11.1
通讯作者：
M. Avron
中科院分区：
文献类型：
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作者：
A. Oren;E. Padan;M. Avron
通过对蓝藻(Oscillatoria Limnetica)产氧光合作用(H(2)O为电子供体)和缺氧光合作用(H(2)S为电子供体)光合作用量子产额谱的比较，揭示了缺氧光合作用只受光系统I的驱动。后者的最高量子产率(最大为0.059个CO(2)分子/吸收光量子)是优先激发以叶绿素a和类胡萝卜素为主要色素的光系统I的波长。3-(3，4-二氯苯基)-1，1-二甲基脲的加入对光合作用没有影响，光优先激发光系统II的光的叠加也没有提高量子效率，光系统II有效地利用了较窄的吸收光谱范围(550-650 nm)，光通过藻蓝蛋白提供给光系统II。量子产额(0.033个CO(2)分子/吸收光量子)比理论产额低3倍，这可能是由于光系统II向光系统I的低效光传递所致。因此，通过光系统I光的叠加，该地区的氧合光合作用增强了3倍，而缺氧光合作用的量子产额很低。这些结果与这样的蓝藻代表光养进化的中间阶段的说法是一致的。
A comparison of the quantum yield spectra of the oxygenic (H(2)O as the electron donor) with the anoxygenic (H(2)S 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 CO(2) 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 CO(2) 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.