Storage carbon metabolism of Isochrysis zhangjiangensis under different light intensities and its application for co-production of fucoxanthin and stearidonic acid

• DOI: 10.1016/j.biortech.2019.02.127
• Publication Date: 2019-03-01T22:39:12Z
• Authors: Yuelian Li; Han Sun; Tao Wu; Yunlei Fu; Yongjin He; Xuemei Mao; Feng Chen
• Keywords: 0301 basic medicine; 03 medical and health sciences; Light; Fatty Acids, Omega-3; Haptophyta; Xanthophylls; Lipid Metabolism; Carotenoids; Lipids; Carbon

This study explored the co-production of fucoxanthin and stearidonic acid from Isochrysis zhangjiangensis by investigating its carbon metabolism under different light intensities. Results showed high light inhibited the synthesis of fucoxanthin and stearidonic acid, while promoted cell growth and enhanced cellular lipid content compared with low light, achieving 2.4 g/L and 28.55%, respectively. Low light accelerated the accumulation of fucoxanthin and stearidonic acid, which obtained 23.29 mg/g and 17.16% (of total fatty acid). In combination with the molecular analysis, low light redirected carbon skeletons into glyceraldehyde-3-phosphate and diverted into carotenoid especially fucoxanthin. While, high light redistributed the skeletons to Malonyl CoA, citrate and α-Ketoglutarate and then oriented into lipid metabolism. The highest fucoxanthin and stearidonic acid productivity was 2.94 mg L-1 d-1 and 4.33 mg L-1 d-1, respectively, which revealed I. zhanjiangensis is a potential strain for the co-production of fucoxanthin and stearidonic acid.