Enhanced astaxanthin production from a novel strain of Haematococcus pluvialis using fulvic acid

Haematococcus pluvialis is one of the most promising natural sources of astaxanthin. Morphological and genomic characterization of a novel strain of H. pluvialis LUGU, which was isolated from Lugu Lake in Yunnan Plateau, was described in this study. The algae can accumulate astaxanthin under abiotic stress. Thus, the influences of fulvic acid (FA) on biomass and astaxanthin were investigated, and transcriptional levels of three astaxanthin biosynthetic genes in H. pluvialis, namely, phytoene desaturase gene (PDS), lycopene cyclase gene (LCY), and n-carotene hydroxylase gene (CHY), were measured. The astaxanthin content increased by 86.89% and 9.78% in 5 and 10 mg L-1 FA-treated algal cells, respectively. The transcriptional levels of PDS and CHY genes were also enhanced under FA induction. Results suggested that high level of astaxanthin accumulation may correlate astaxanthin biosynthetic genes with FA induction. This research demonstrated a useful strategy to efficiently produce astaxanthin by using H. pluvialis. (C) 2015 Elsevier Ltd. All rights reserved.