Enhanced production of astaxanthin at different physico-chemical parameters in the green alga Haematococcus pluvialis Flotow

In the present study, the effects of pH, light intensities, various inorganic nitrogen sources, NaCl, K2HPO4 and different light periods were investigated on the vegetative cells of Haematococcus pluvialis Flotow. Maximum level of total carotenoids were (68.59 µg/mL) at pH 7.0, light intensities (73.57 µg/mL) at 40.0 µEm -2 s -1 , 0.2 M of NaNO3 (67.49 µg/mL), 2.0 mM of CH4N2O (63.32 µg/mL) and 2.0 mM of NH4Cl (66.21 µg/mL), 0.06 M of K2HPO4 (77.65 µg/mL) 0.06 M of NaCl (68.26 µg/mL) correspondence to maximum number of cells 6.62, 6.31, 6.31, 6.52, 6.81, 6.51 and 6.41 log10 cell number/mL respectively. In addition, the alga kept under different light periods, the organism had maximum production of carotenoid of 69.50, 98.65 and 37.55 µg/mL under mixotrophic, phototrophic and heterotrophic conditions, respectively. Based on the investigation a Modified HP medium-I was proposed and compared the growth characteristics of the test alga with Modified 3N+BBM+V medium. The organism had maximum content of carotenoids of 97.13 µg/mL at Modified HP medium-I as against 78.32 µg/mL with Modified 3N+BBM+V medium on 27 th day. It was concluded that phosphate and light intensity were greatly influencing the accumulation of total carotenoids of the alga.