State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, PR China.
College of Oceanography, Hohai University, Nanjing 210098, PR China.
J Biotechnol. 2021 Nov 20;341:168-174. doi: 10.1016/j.jbiotec.2021.09.017. Epub 2021 Sep 29.
Haematococcus pluvialis is the prime source of natural astaxanthin for commercial exploitation. The large-scale cultivation of H. pluvialis is one of the key technologies for the development of natural astaxanthin industry. So far, horizontal tubular photobioreactor (HTPBR) circulated by a centrifugal pump has been the main PBR for the large-scale cultivation of H. pluvialis. Shear stress is a negative factor in microalgal cultivation at different scales, particularly for large-scale cultivation. To reduce the adverse impact of shear stress, the tolerance of H. pluvialis to the shear stress during the induction stage was first investigated in this study. H. pluvialis aplanospore was not sensitive to stresses between 19.18 and 27.32 Pa, but was resulted in about 30% cell death under shear stress between 27.32 and 63.84 Pa. Accordingly, two centrifugal pumps with different impellers was selected in 400 L HTPBRs to study the outdoor photoinduction for astaxanthin accumulation. The highest astaxanthin productivity and astaxanthin concentration were obtained in HTPBRs using a centrifugal pump equipped with three unshrouded backward-bladed impellers. The HTPBR was then successfully scaled up to 800 L with a similar performance, showing good scalability.
雨生红球藻是商业开发天然虾青素的主要原料。大规模培养雨生红球藻是天然虾青素产业发展的关键技术之一。到目前为止，通过离心泵循环的水平管式光生物反应器（HTPBR）一直是大规模培养雨生红球藻的主要 PBR。在不同规模的微藻培养中，剪切力都是一个负面因素，特别是在大规模培养中。为了降低剪切力的不利影响，本研究首先研究了雨生红球藻在诱导阶段对剪切力的耐受能力。雨生红球藻游动孢子对 19.18 至 27.32 Pa 的压力不敏感，但在 27.32 至 63.84 Pa 的剪切力下，细胞死亡率约为 30%。因此，在 400 L HTPBR 中选择了两种具有不同叶轮的离心泵，以研究户外光诱导虾青素积累。在配备三个无罩后掠式叶轮的离心泵的 HTPBR 中，获得了最高的虾青素生产力和虾青素浓度。然后，该 HTPBR 成功扩展到 800 L，性能相似，显示出良好的可扩展性。
