Zhang Litao, Su Fang, Zhang Chunhui, Gong Fengying, Liu Jianguo
Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China.
National-Local Joint Engineering Research Center for Haematococcus pluvialis and Astaxanthin, Yunnan Alphy Biotech Co., Ltd., Chuxiong 675012, China.
Int J Mol Sci. 2016 Dec 26;18(1):33. doi: 10.3390/ijms18010033.
The cell transformation from green motile cells to non-motile cells and astaxanthin accumulation can be induced in the green alga cultured outdoors. In the initial 3 d of incubation (cell transformation phase), light absorption and photosynthetic electron transport became more efficient. After five days of incubation (astaxanthin accumulation phase), the light absorption per active reaction center (ABS/RC) increased, but the efficiency of electron transport () and the quantum yield of electron transport () decreased with increased time, indicating that the capacity of photosynthetic energy utilization decreased significantly during astaxanthin accumulation, leading to an imbalance between photosynthetic light absorption and energy utilization. It would inevitably aggravate photoinhibition under high light, e.g., at midday. However, the level of photoinhibition in decreased as the incubation time increased, which is reflected by the fact that / determined at midday decreased significantly in the initial 3 d of incubation, but was affected very little after seven days of incubation, compared with that determined at predawn. This might be because the non-photochemical quenching, plastid terminal oxidase, photosystem I cyclic electron transport, defensive enzymes and the accumulated astaxanthin can protect cells against photoinhibition.
在室外培养的绿藻中，可诱导细胞从绿色游动细胞转变为非游动细胞并积累虾青素。在培养的最初3天（细胞转化阶段），光吸收和光合电子传递变得更高效。培养5天后（虾青素积累阶段），每个活性反应中心的光吸收（ABS/RC）增加，但电子传递效率（）和电子传递量子产率（）随时间增加而降低，这表明在虾青素积累过程中光合能量利用能力显著下降，导致光合光吸收与能量利用之间失衡。这将不可避免地加剧高光强下（如中午）的光抑制。然而，随着培养时间增加，中的光抑制水平降低，这体现在中午测定的/在培养最初3天显著下降，但与黎明前测定的值相比，培养7天后受影响很小。这可能是因为非光化学猝灭、质体末端氧化酶、光系统I循环电子传递、防御性酶以及积累的虾青素可保护细胞免受光抑制。
