A novel two-stage culture strategy to enhance the C-phycocyanin productivity and purity of Arthrospira platensis
Youzhi Yu, Xiaoyu Hou, Qing Yu, Yan Huo, Kaixuan Wang, Xiaobin Wen, Yi Ding, Yeguang Li, Zhongjie Wang
Abstract
The inconsistent light intensity requirements for C-phycocyanin accumulation and algal growth have greatly hampered the productivity and quality of this high-value pigment protein. This study aimed to improve both the production efficiency and extract quality of C-phycocyanin in the cyanobacterium Arthrospira platensis HN5, by adjusting light intensity and nitrogen supply at different cultivation stages. We established an optimized two-stage culture strategy consisting of a 4-d phase for algal growth under 320 μmol m−2 s−1 and a subsequent 2-d period using 160 μmol m−2 s−1 illumination and NaNO3 supplement to promote C-phycocyanin accumulation. By adopting this strategy, up to 18.86% content and 59.72 mg L−1 d−1 productivity of C-phycocyanin were obtained. Our results indicate that the increased C-phycocyanin content improved the quality of C-phycocyanin extract, and reactive grade C-phycocyanin (A620/A280 = 3.16) was recovered through a one-step ammonium sulfate precipitation. The established two-stage culture strategy, as illustrated herein, could be a highly promising strategy for improving the content and productivity of C-phycocyanin and effectively enhancing the quality of C-phycocyanin products, which could be particularly conducive to the large-scale development of this algal pigment in the food industry sector.