Otto Schott Institute of Materials Research, University of Jena, Fraunhoferstrasse 6, 07743, Jena, Germany.
Abbe Center of Photonics, University of Jena, Albert-Einstein-Strasse 6, 07745, Jena, Germany.
Sci Rep. 2019 Jul 3;9(1):9600. doi: 10.1038/s41598-019-45955-w.
Photoautotrophic microbes present vast opportunities for sustainable lipid production, CO storage and green chemistry, for example, using microalgae beds to generate biofuels. A major challenge of microalgae cultivation and other photochemical reactors is the efficiency of light delivery. In order to break even on large scale, dedicated photon management will be required across all levels of reactor hierarchy - from the harvesting of light and its efficient injection and distribution inside of the reactor to the design of optical antenna and pathways of energy transfer on molecular scale. Here, we discuss a biomimetic approach for light dilution which enables homogeneous illumination of large reactor volumes with high optical density. We show that the immersion of side-emitting optical fiber within the reactor can enhance the fraction of illuminated volume by more than two orders of magnitude already at cell densities as low as ~5 10 ml. Using the green algae Haematococcus pluvialis as a model system, we demonstrate an increase in the rate of reproduction by up to 93%. Beyond micoralgae, the versatile properties of side-emitting fiber enable the injection and dilution of light with tailored spectral and temporal characteristics into virtually any reactor containment.
光自养微生物为可持续的脂质生产、CO2 储存和绿色化学提供了巨大的机会，例如，利用微藻床来生产生物燃料。微藻培养和其他光化学反应器的一个主要挑战是光传递的效率。为了在大规模生产中收支平衡，将需要在反应器层次的所有级别上进行专门的光子管理——从光的收集及其在反应器内部的高效注入和分布，到光学天线的设计和分子尺度上的能量转移途径。在这里，我们讨论了一种用于光稀释的仿生方法，该方法可以实现高光学密度的大反应器体积的均匀照明。我们表明，在细胞密度低至约 5×10^6 个/ml 时，将侧发光光纤浸入反应器内即可将受照体积的分数提高两个数量级以上。使用绿藻雨生红球藻作为模型系统，我们证明繁殖速度提高了 93%。除了微藻之外，侧发光光纤的多功能特性使得可以将具有定制光谱和时间特性的光注入和稀释到几乎任何反应器容器中。
