Sánchez O, van Gemerden H, Mas J
Department of Genetics and Microbiology, Autonomous University of Barcelona, E-08193 Bellaterra, Spain.
Arch Microbiol. 1998 Nov;170(6):405-10. doi: 10.1007/s002030050660.
The photosynthetic response of the purple sulfur bacterium Chromatium vinosum DSM 185 to different degrees of illumination was analyzed. The microorganism was grown in continuous culture, and samples were taken from the effluent of the culture and incubated at different irradiances to determine the specific rate of sulfur oxidation as a measure of the photosynthetic activity of the organism. The activities obtained were plotted as a function of the specific rate of light uptake, and for each set of data a photosynthesis equation was fitted, which allowed the estimation of Pmax (photosynthetic capacity), qk (the threshold irradiance for light limitation), and m (maintenance coefficient). The results indicated that cells grown under light limitation are able to achieve higher photosynthetic activities than cells grown under light saturation. The photosynthetic capacity (Pmax) remained constant under all the conditions of illumination tested, while the maintenance expenses (m) were higher under light limitation. The parameter qk, on the contrary, decreased considerably at limiting irradiances.
分析了紫色硫细菌嗜酒色杆菌DSM 185对不同光照程度的光合响应。该微生物在连续培养条件下生长，从培养物流出物中取样，并在不同辐照度下孵育，以确定硫氧化的比速率，作为该生物体光合活性的度量。将获得的活性绘制为光吸收比速率的函数，并对每组数据拟合一个光合作用方程，从而可以估算Pmax（光合能力）、qk（光限制的阈值辐照度）和m（维持系数）。结果表明，在光限制条件下生长的细胞比在光饱和条件下生长的细胞能够实现更高的光合活性。在所有测试的光照条件下，光合能力（Pmax）保持恒定，而在光限制条件下维持费用（m）更高。相反，参数qk在限制辐照度下显著降低。
