Xue Shengzhang, Zhang Qinghua, Wu Xia, Cong Wei
National Key Laboratory Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China.
Sheng Wu Gong Cheng Xue Bao. 2011 Apr;27(4):606-13.
The knowledge of oxygen evolution characteristics, which is a symbol of photosynthetic activity, under various light conditions is important for photobioreactor design and operation. In this study, we constructed a device to investigate oxygen evolution characteristics of Spirulina platensis under two different light regimes: 1) continuous illumination of various light intensities (14-6 500 micromol/(m2 x s)); 2) medium frequency L/D cycles of four different light intensities (69, 505, 1 330, 4 265 micromol/(m2s)). Light limited region, intermediate region, light saturated region and light inhibited region of light intensity were recognized according to their relationship with oxygen evolution rate (OER) under continuous illumination. Investigation of S. platensis under L/D cycles showed whether photosynthetic efficiency could be increased with increasing L/D frequency largely depended on the light intensity applied. The higher the light intensity, the larger the photosynthetic enhancement could be expected with the increase of L/D frequency. The largest light integration effect was found under L/D cycles of high light intensity (4 265 micromol/(m2 x s)) and medium light fraction (k = 0.6), while light integration effect was totally absent under low light fractions (k < 0.2). We also discussed their implications to the practical aspects of microalgae cultivation.
光合活性的一个标志是放氧特性，了解其在各种光照条件下的情况对于光生物反应器的设计和运行至关重要。在本研究中，我们构建了一个装置，以研究钝顶螺旋藻在两种不同光照模式下的放氧特性：1）各种光照强度（14 - 6500微摩尔/（平方米·秒））的连续光照；2）四种不同光照强度（69、505、1330、4265微摩尔/（平方米·秒））的中频光暗循环。根据连续光照下光强度与放氧速率（OER）的关系，确定了光强度的光限制区、中间区、光饱和区和光抑制区。对钝顶螺旋藻在光暗循环下的研究表明，光合效率是否会随着光暗循环频率的增加而提高，很大程度上取决于所施加的光强度。光强度越高，随着光暗循环频率的增加，光合增强效果可能越大。在高光强度（4265微摩尔/（平方米·秒））和中等光分率（k = 0.6）的光暗循环下发现了最大的光积分效应，而在低光分率（k < 0.2）下则完全没有光积分效应。我们还讨论了它们对微藻培养实际应用方面的影响。
