A strategy for boosting astaxanthin accumulation in green microalga Haematococcus pluvialis by using combined diethyl aminoethyl hexanoate and high light

Haematococcus pluvialis is one of the best natural sources of the high-value antioxidant astaxanthin. The use of biotic or abiotic elicitors is an effective strategy to improve astaxanthin production. In this study, a strategy combining diethyl aminoethyl hexanoate (DA-6) and high light was used to promote the accumulation of astaxanthin in H. pluvialis LUGU. The effect of DA-6 on the astaxanthin content, reactive oxygen species (ROS), and transcriptional expression of six astaxanthin biosynthetic genes in H. pluvialis LUGU was investigated. The results showed that treatment with 0.1 mM DA-6 increased the astaxanthin content to 30.95 mg g−1, which was 2.01-fold higher than that of the control (15.43 mg g−1). Moreover, adding exogenous DA-6 significantly accelerated the transcription of chy, pds, and ptox2, which are responsible for substrate conversion and electron transport during the process of astaxanthin formation under conditions of high light. The level of reactive oxygen species (ROS) and the upregulation of astaxanthin biosynthesis-related genes increased astaxanthin accumulation under DA-6 high light conditions. This work is beneficial in developing an efficient strategy for the hyperproduction of astaxanthin.