The associative induction of succinic acid and hydrogen sulfide for high-producing biomass, astaxanthin and lipids in Haematococcus pluvialis.

To obtain higher yield of natural astaxanthin, the present study aims to develop a viable and economic induction strategy for astaxanthin production comprising succinic acid (SA) combined with sodium hydrosulfide (NaHS). The biomass (1.33 g L-1), astaxanthin concentration (44.96 mg L-1), astaxanthin content (163.55 pg cell-1), and lipid content (55.34%) were achieved under 1.0 mM SA and 100 μM NaHS treatment. These results were concomitant with enhanced hydrogen sulfide (H2S) but diminished reactive oxide species (ROS). Further study discovered that endogenous H2S could improve astaxanthin and lipid coproduction under SA induction by mediating related gene transcript levels and ROS signalling. Additionally, the concentrations of biomass and astaxanthin increased to 2.14 g L-1 and 66.25 mg L-1, respectively, under the induction of SA and NaHS in a scaled-up bioreactor. Briefly, the work proposed a novel feasible strategy for high yields of biomass and astaxanthin by H. pluvialis.