Department of Agriculture, Polytechnic School of Girona, Polytechnic University of Catalunya, 17002 Girona, Spain.
Appl Environ Microbiol. 1987 Apr;53(4):864-71. doi: 10.1128/aem.53.4.864-871.1987.
The size frequency distribution of planktonic cells of purple sulfur phototrophic bacteria was measured at several depths in a bacterial layer of Lake Cisó (Spain). The bacterioplankton was dominated by Chromatium minus (87 to 94% of the total biomass). The largest cells of C. minus were found in the top part of the bacterial layer. In addition, the in situ and potential specific photosynthetic activity (CO(2) fixation and acetate uptake) and specific pigment content were measured in relation to several key environmental parameters that determine the activity of cells. Potential growth rates were estimated from production rates and biomass. A maximal specific growth rate of 0.074 h was found for the top part of the bacterial layer. Photosynthesis versus light and versus sulfide curves among field samples indicated that light was the main limiting factor controlling the activity of C. minus in Lake Cisó. The specific bacteriochlorophyll a content was very high in all samples (0.27 to 0.36 mug mug of C). Results of laboratory experiments performed with pure cultures indicated that the average cell volume changes from 5.9 to 20.0 mum and that differences in growth rate, breakdown, or synthesis of sulfur and glycogen and degradation of the photosynthetic apparatus are the main factors accounting for the observed changes in cell volume across the bacterial layer.
在西班牙 Cisó 湖的一个细菌层的几个深度测量了浮游细菌的大小频率分布。浮游细菌主要由紫色硫光合细菌（Chromatium minus）组成（占总生物量的 87%至 94%）。最小的 Chromatium minus 细胞最大的细胞位于细菌层的顶部。此外，还测量了与决定细胞活性的几个关键环境参数有关的原位和潜在特定光合作用（CO(2)固定和乙酸盐摄取）和特定色素含量。从生产力和生物量估算了潜在生长速率。发现细菌层顶部的最大特定生长速率为 0.074 h。现场样本的光合作用与光和与硫化物的关系曲线表明，光是控制 Cisó 湖最小 Chromatium minus 活性的主要限制因素。所有样本中的特定细菌叶绿素 a 含量都非常高（0.27 至 0.36 mug mug C）。用纯培养物进行的实验室实验结果表明，平均细胞体积从 5.9 变为 20.0 微米，并且硫和糖原的生长速率、分解或合成以及光合装置的降解的差异是导致细菌层中观察到的细胞体积变化的主要因素。
