Algal cells are highly complex optical systems that can dynamically change their structure. Consequently, absorption and scattering properties of algae change, while the cells are acclimating to different light conditions or during growth and division in a cell cycle. This may be particularly important in algal species that can grow rapidly under very high-light such as Chlorella vulgaris IPPAS C-1 that is studied here. From cell transmittance measured conventionally and using integrating sphere, we evaluated absorption and scattering coefficients and cross sections per cell dry weight and chlorophyll content. This was done for asynchronous cell culture grown in low-light (LL; 220 μmol (photons) m⁻² s⁻¹) or high-light (HL; 1760 μmol (photons) m⁻² s⁻¹) light, as well as during cell cycle of synchronous culture grown in HL. During the cell cycle, we also determined cell ultrastructural organization by transmission electron microscopy, and correlated its parameters with absorption and scattering cross sections per cell dry weight. We found that the IPPAS C-1 cells of asynchronous culture scatter light more than other cells, however, internal organization of the cells that is decisive for scattering is less sensitive to HL and LL treatment than the cell pigment content that controls absorption. The light scattering and absorption were dynamically changed during cell cycle of synchronous cells grown in the HL. Changes in ratio of chloroplast to protoplast area, reflecting amount of scattering chloroplast membrane (outer, inner) interfaces, best correlated with changes in light scattering. We suggest that the increased light scattering by the HL-acclimated IPPAS C-1 cells might be responsible for increased HL resilience reported in the literature. Biotechnological aspect of this study is that the scattering and absorption properties of phytoplankton cells ought to be calibrated for each particular growth phase or irradiance to which the cells are acclimated.

藻类细胞是高度复杂的光学系统，可以动态改变其结构。因此，当细胞适应不同的光照条件或在细胞周期的生长和分裂过程中，藻类的吸收和散射特性发生了变化。这对于可以在非常高的光照下快速生长的藻类物种尤其重要，例如此处研究的小球藻IPPAS C-1。根据常规测量并使用积分球的细胞透射率，我们评估了吸收和散射系数以及每细胞干重和叶绿素含量的横截面。对于在低光（LL; 220μmol（光子）m ^-2  s ^-1）或高光（HL; 1760μmol（光子）m ^-2）下生长的异步细胞培养进行此操作 s ^-1）以及在HL中同步培养的细胞周期中。在细胞周期中，我们还通过透射电子显微镜确定了细胞的超微结构，并将其参数与每细胞干重的吸收和散射截面相关联。我们发现异步培养的IPPAS C-1细胞比其他细胞散射更多的光，但是，决定散射的细胞内部组织对HL和LL处理的敏感性低于控制吸收的细胞色素含量。在HL中生长的同步细胞的细胞周期中，光的散射和吸收是动态变化的。叶绿体与原生质体面积比的变化反映了叶绿体膜（外​​部，内部）界面的散射量，与光散射的变化最相关。我们建议，通过HL适应的IPPAS C-1细胞增加的光散射可能是文献报道的增加的HL复原力的原因。这项研究的生物技术方面是，应针对细胞适应的每个特定生长期或辐照度，对浮游植物细胞的散射和吸收特性进行校准。