Cook J R
Plant Physiol. 1966 May;41(5):821-5. doi: 10.1104/pp.41.5.821.
Axenic populations of the photosynthetic protozoan Euglena gracilis, grown with autotrophic nutrition, were synchronized with respect to cell division by culture on an alternating light-dark cycle. No cell divisions occurred in the light periods; approximately 100% of the cells divided in the dark periods. In such cultures, the synthesis of photosynthetic pigments and accumulation of polysaccharide were confined to the light periods. The capacity for photosynthesis, however, increased continuously over the entire light-dark cycle, and is thus not directly correlated with pigment content. A correlation was seen between photosynthetic capacity and protein content, suggesting that enzymatic mechanisms of the photosynthetic apparatus might be the limiting factor. Estimates of total photosynthetic activity indicate that about 5 x 10(-6) calories are required for the synthesis of a new cell.
在自养营养条件下培养的光合原生动物纤细裸藻的无菌群体，通过在交替明暗周期下培养使其细胞分裂同步。在光照期不发生细胞分裂；约100%的细胞在黑暗期分裂。在这样的培养物中，光合色素的合成和多糖的积累局限于光照期。然而，光合作用能力在整个明暗周期中持续增加，因此与色素含量没有直接相关性。观察到光合作用能力与蛋白质含量之间存在相关性，这表明光合装置的酶促机制可能是限制因素。总光合活性的估计表明，合成一个新细胞大约需要5×10(-6)卡路里。
