Wu Kebi, Ying Kezhen, Liu Lu, Zhou Jin, Cai Zhonghua
School of Life Sciences, Tsinghua University, Beijing, 100086, PR China.
Shenzhen Public Platform for Screening and Application of Marine Microbial Resources, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, PR China.
Biotechnol Rep (Amst). 2020 Mar 12;26:e00444. doi: 10.1016/j.btre.2020.e00444. eCollection 2020 Jun.
(), a promising source for astaxanthin production, is a light-sensitive microalga that is prone to sluggish growth when subjected to high levels of irradiance. A challenge in culture is to find a way to efficiently use illumination to maintain vigorous growth and harvest dense biomass, which is essential for further exploiting the potential for astaxanthin production. Previous studies have shown that in addition to illumination, carbon supply in culture is a key limitation for algae growth. Here, we investigated a combined culture approach involving high light intensity (110 μmol ms) and injection of a 1% (v/v) CO air-gas mixture which provided an effective method for culture to achieve both a high growth rate and high cell density. The cell number in the group with high light exposure combined with CO enrichment was increased almost four-fold compared with a high light group (110 μmol ms without CO injection). Additional experiments suggested a possible mechanism in which elevated CO increases the electron sink capacity, thus alleviating photoinhibition and oxidative damage. The scaled-up photobioreactor demonstrated much better performance, with growth rates improved by 50-350 %, providing further evidence that this new method can improve algal cell production. Overall, our work provides an efficient way for culture and manufacture, with potential industrial applications.
（）是虾青素生产的一个有前景的来源，是一种对光敏感的微藻，当受到高水平辐照时容易生长缓慢。培养中的一个挑战是找到一种有效利用光照来维持旺盛生长并收获高密度生物量的方法，这对于进一步开发虾青素生产潜力至关重要。先前的研究表明，除了光照外，培养中的碳供应是藻类生长的关键限制因素。在这里，我们研究了一种联合培养方法，包括高光强度（110 μmol m⁻² s⁻¹）和注入1%（v/v）的CO₂空气混合气体，这为培养提供了一种有效的方法，以实现高生长速率和高细胞密度。与高光组（110 μmol m⁻² s⁻¹且不注入CO₂）相比，高光暴露与CO₂富集相结合的组中的细胞数量增加了近四倍。额外的实验提出了一种可能的机制，即升高的CO₂增加了电子汇容量，从而减轻了光抑制和氧化损伤。放大的光生物反应器表现出更好的性能，生长速率提高了50 - 350%，进一步证明了这种新方法可以提高藻类细胞产量。总体而言，我们的工作为培养和制造提供了一种有效的方法，具有潜在的工业应用。
