Melatonin and calcium act synergistically to enhance the coproduction of astaxanthin and lipids in Haematococcus pluvialis under nitrogen deficiency and high light conditions

• Published in: Bioresource technology Vol. 305; p. 123069
• Main Authors: Cui, Jing, Yu, Chunli, Zhong, Du-bo, Zhao, Yongteng, Yu, Xuya
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.06.2020
• Subjects: Astaxanthin; Calcium; Haematococcus pluvialis; Lipid; Melatonin; Signalling molecules; Melatonin; Calcium; Signalling molecules; Astaxanthin; Lipid; Haematococcus pluvialis
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2020.123069

[Display omitted] •Exogenous MT improved astaxanthin and lipid synthesis in alga under abiotic stress.•Coupling of MT and CaCl2 further enhanced the production of astaxanthin and lipids.•MT and CaCl2 upregulated genes related to the astaxanthin and lipid synthesis.•MT and CaCl2 alleviated oxidative stress by upregulating the level of GSH.•MT and CaCl2 mediated GABA signalling in response to abiotic stress. This study focused on the influence of integrating melatonin (MT) and calcium (Ca2+) on the simultaneous accumulation of astaxanthin and lipids in Haematococcus pluvialis under abiotic stress conditions. Compared with the control condition, MT induction enhanced astaxanthin and lipid contents by 65.89% and 27.38%, respectively. The highest contents of astaxanthin and lipids under combined exposure to MT and Ca2+ were 3.8% and 49.53%, respectively, which were 1.13- and 1.21-fold higher than those of cells treated with MT alone. The application of MT and Ca2+ also promoted the expression of carotenogenic and lipogenic genes and increased the levels of Ca2+ and γ-aminobutyric acid (GABA) but decreased reactive oxygen species (ROS) levels. Further evidence indicated that the increased cellular Ca2+ could promote astaxanthin biosynthesis under MT induction by regulating carotenogenic gene levels and GABA and ROS signalling. The integrated strategy efficiently improved the coproduction of astaxanthin and lipids in H. pluvialis.