Metabolic response of cyanide in Haematococcus pluvialis

Abstract

The green alga Haematococcus pluvialis is able to produce and accumulate large amounts of astaxanthin under stress conditions. In this study H. pluvialis was exposed to different concentrations of cyanide (0, 6, 9 and 12 µM), in two-time periods (treatmenton = 14 days and pre-treatment = 7 days) to compare the changes on growth and biochemical parameters in green and red stages. In green stage, cyanide treatment had not significant effect on dry weight, chlorophyll a and protein content, but increased the amount of chlorophyll b, carotenoid and carbohydrate. In addition, an increase in carbohydrate and carotenoid content was observed in cyanide treatment. Cyanide pre-treatment at low concentration increased and at higher concentrations declined all measured parameters in the green and red stage. Cyanide treatment had better performance in increasing the amount of carotenoids in red cell. The amount of astaxanthin significantly increased in treated and pre-treated algae with cyanide. Pre-treatment with cyanide due to increase in growth, had better influence in enhancing astaxanthin content. These results show that H. pluvialis offer potential to phytoremediation of cyanide and in low concentrations, it can induce astaxanthin accumulation in H. pluvialis.