Yu Wenjie, Zhang Litao, Zhao Jing, Liu Jianguo
Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, China; University of Chinese Academy of Sciences, Beijing 100049, China.
Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, China.
Bioresour Technol. 2021 Dec;341:125788. doi: 10.1016/j.biortech.2021.125788. Epub 2021 Aug 18.
Improvement of astaxanthin yield is a continuing objective in Haematococcus pluvialis cultivation. In this study, a new strategy combining exogenous sodium fumarate (SF) with nitrogen deficiency was demonstrated to promote astaxanthin accumulation in H. pluvialis. SF significantly accelerated astaxanthin synthesis over cell growth. Notably, under nitrogen deficiency, 10 mM SF increased the cellular astaxanthin content by 1.75-fold and 1.47-fold on day 7 and 12, respectively. Further studies indicated that SF increased the level of respiratory metabolites in the Embden-Meyerhof-Parnas pathway, tricarboxylic acid cycle and pentose phosphate pathway. An enhanced substrate pool due to the acceleration of respiratory metabolic pathways directly induced astaxanthin synthesis. Meanwhile, the accumulation of C18:1, C18:2 and C18:3 fatty acids enhanced astaxanthin synthesis indirectly by promoting the process of esterification. This study not only helps to elucidate the role of respiratory metabolic pathways in astaxanthin synthesis but also provides a new effective technique to improve astaxanthin production.
提高虾青素产量是雨生红球藻培养过程中的一个持续目标。在本研究中，一种将外源富马酸钠（SF）与缺氮相结合的新策略被证明可促进雨生红球藻中虾青素的积累。与细胞生长相比，SF显著加速了虾青素的合成。值得注意的是，在缺氮条件下，10 mM SF在第7天和第12天分别使细胞内虾青素含量增加了1.75倍和1.47倍。进一步研究表明，SF提高了糖酵解途径、三羧酸循环和磷酸戊糖途径中呼吸代谢物的水平。呼吸代谢途径加速导致底物池增强，直接诱导了虾青素的合成。同时，C18:1、C18:2和C18:3脂肪酸的积累通过促进酯化过程间接增强了虾青素的合成。本研究不仅有助于阐明呼吸代谢途径在虾青素合成中的作用，还提供了一种提高虾青素产量的新有效技术。
