Role of media composition in biomass and astaxanthin production of Haematococcus pluvialis under two-stage cultivation

In the present study, the effects of four different culture media on the growth, astaxanthin production and morphology of Haematococcus pluvialis LUGU were studied under two-step cultivation. The interactions between astaxanthin synthesis and secondary messengers, reactive oxygen species (ROS) and mitogen-activated protein kinases (MAPK) were also investigated. In the first green vegetative cell stage, maximal biomass productivity (86.54 mg L^?1 day^?1) was obtained in BBM medium. In the induction stage, the highest astaxanthin content (21.5 mg g^?1) occurred in BG-11 medium, which was higher than in any other media. The expressions of MAPK and astaxanthin biosynthetic genes in BG-11 were higher than in any other media, whereas the ROS content was lower. Biochemical and physiological analyses suggested that the ROS, MAPK and astaxanthin biosynthetic gene expression was involved in astaxanthin biosynthesis in H. pluvialis under different culture media conditions. This study proposes a two-step cultivation strategy to efficiently produce astaxanthin using microalgae.