Light intensity effects on pigment composition and organisation in the green sulfur bacterium Chlorobium tepidum
Light intensity effects on pigment composition and organisation in the green sulfur bacterium Chlorobium tepidum
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DOI：
10.1023/a:1006161302838
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发表时间：
1999-03-01
影响因子：
3.7
通讯作者：
Cox, RP
中科院分区：
文献类型：
--
作者：
Borrego, CM;Gerola, PD;Cox, RP
我们研究了生长在不同光强下的绿色硫细菌Chlorobium tepidum捕光器的色素组成和组织的变化。在较低的光照强度下生长的细胞具有较低的指数增长率和增加的主要捕光色素，细菌叶绿素c和类胡萝卜素，细胞蛋白质的基础上。在低光强度下生长的细胞中分离的叶绿体的吸收光谱显示，细菌叶绿素c的Q（y）带中的红移高达8 nm，而高光生长的细胞中的叶绿体。在相应的荧光发射峰中也观察到了高达4 nm的类似红移。色素提取物的HPLC分析表明，红移和更多的烷基化BChl C同系物的含量之间的相关性，这增加了生长的光强度较低。此外，在叶绿体类胡萝卜素的组成分析揭示了显着的变化之间的比率chlorobutene和1 '，2'-dihydrochlorobutene，这显着降低，从5到0.7，在光限制的文化。
We have investigated the changes in the pigment composition and organisation of the light-harvesting apparatus of the green sulfur bacterium Chlorobium tepidum growing under different light intensities. Cells grown at lower light intensities had lower exponential growth rates and increased amounts of the main light-harvesting pigments, bacteriochlorophyll c and carotenoids, on a cell protein basis. Absorption spectra of chlorosomes isolated from cells grown at low light intensities revealed a red-shift of up to 8 nm in the Q(y) band of bacteriochlorophyll c compared to chlorosomes from high light grown cells. A similar red-shift of up to 4 nm was also observed in the corresponding fluorescence emission peaks. HPLC analysis of pigment extracts showed a correlation between the red-shift and the content of the more alkylated BChl c homologs, which increased as light intensity for growth was lower. Furthermore, analysis of the carotenoid composition in chlorosomes revealed a conspicuous change in the ratio between chlorobactene and 1', 2'-dihydrochlorobactene, which dramatically decreased from 5 to 0.7 in light-limited cultures.