Effect of Azide on Growth Parameters of Haematococcus pluvialis in Green and Red Stages

Haematococcus pluvialis can accumulate large amounts of astaxanthin under stress conditions. Azide as an effective respiratory inhibitor can induce oxidative stress. In this study, the effect of pre-treatment (7 days) and treatment (14 days) of different concentrations of azide (0, 25, 50, and 100 μM) was investigated on growth and biochemical parameters in green and red cells. Azide treatment and pre-treatment caused a decrease in all measured parameters except for the carotenoid in the green stage. Carotenoid content did not show any changes in azide treatment but pre-treatment with low concentration induced carotenoid accumulation in the green stage. The dry weight, protein, and carbohydrate amount did not change in red cells treated with azide, but carotenoid content decreased in these cells. Pre-treated with azide hurt the amount of protein and carbohydrates but increased the carotenoid content. Azide pre-treatment had better performance in increasing the carotenoid amount in red cells. These results showed that H. pluvialis has good potential for phytoremediation of azide and carotenoid accumulation.