Research
| Title： | A novel fed-batch strategy to boost cyst cells production based on the understanding of intracellular carbon and nitrogen metabolism in Haematococcus pluvialis |
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| First author： | Lu, Zhe; Zheng, Lingling; Liu, Jin; Dai, Jingcheng; Song, Lirong |
| Journal： | BIORESOURCE TECHNOLOGY |
| Years： | 2019 |
| DOI： | 10.1016/j.biortech.2019.121744 |
| Abstract： | Haematococcus pluvialis is a prominent feedstock of astaxanthin. The ratio of carbon to nitrogen (C/N) strongly influences the metabolic pathways of mixotrophic-grown microalgae, however, its role involved in astaxanthin biosynthesis is still not fully understood. In this study, integrative metabolic and physiologic profiles were analyzed in elucidating how C/N affected carbon and nitrogen assimilation and thereby exerted influence on astaxanthin biosynthesis. It was demonstrated that high C/N up-regulated the activities of acetate kinase by increase of 5.76 folds in early logarithmic phase, leading a significant increase of acetyl-CoA. The increased carbon skeletons were then funneled into astaxanthin biosynthesis. Additionally, high C/N increased the proportion of carotenoid-intermediates in cytoplasm from chloroplast. Finally, a fed-batch cultivation strategy based on C/N gradient was developed. Biomass attained 9.18 g L-1 in 100% type of immotile cyst cells, which presented astaxanthin productivity at 15.45 mg L-1 d(-1) afterward, exhibiting a promising paradigm in commercial production. |
