Role of copper in the enhancement of astaxanthin and lipid coaccumulation in Haematococcus pluvialis exposed to abiotic stress conditions

This study investigated the effects of copper (Cu) on astaxanthin and lipid biological synthesis in unicellular alga Haematococcus pluvialis under high-light (HL) and nitrogen-deficiency (ND) conditions. During a 15-day cultivation period, the astaxanthin and lipid contents reached the peak values (3.32% and 47.72%) under 6 mu M Cu treatment, which were increased by 66.87% and 34.99% compared to nontreated group, respectively. The application of Cu also increased the transcriptional expression of biosynthesis genes and antioxidant enzymerelated genes, as well as increased the intracellular calcium (Ca2+) level but led to a decrease in reactive oxygen species (ROS) levels. Additionally, Cu treatment induced the activation of calcium-dependent protein kinases (CDPKs) and mitogen-activated protein kinases (MAPKs). This approach simultaneously facilitated astaxanthin and lipid production, and the role of Cu were elucidated on the regulation of signal transduction (e.g., Ca2+, CDPK, MAPK and ROS) in the carotenogenesis and lipogenesis in H. pluvialis.

Automated summary

Copper treatment significantly increased astaxanthin and lipid synthesis in Haematococcus pluvialis, leading to upregulation of biosynthesis genes and antioxidant enzyme-related genes, as well as a decrease in reactive oxygen species levels. Additionally, copper induced the activation of protein kinases, facilitating the production of astaxanthin and lipids in the algae.