Abstract

IMPACT OF LIGHT AND DARK PERIOD AND MONOCHROMATIC LIGHT ON THE GROWTH AND PIGMENT COMPOSITION OF GREEN ALGA HAEMATOCOCCUS PLUVIALIS

Surendra Singh and Ashaq Hussain Rather*

ABSTRACT

Haematococcus pluvialis is one of the best source of astaxanthin (3, 3'- dihydroxy-β,β'-carotene-4,4'-dione), a ketocarotenoid pigment. Light, Temperature, pH, turbidity, nutrients and aeration are the factors responsible for the growth of photosynthetic organisms. Among them, the light is the most crucial factor for the growth and the accumulation of pigments. In the present study, H.pluvialis was incubated outside the controlled air conditioned culture room and was exposed to direct sunlight, of light dark period of 10:14 h (L/D) at 32 ± 2 temperature, in Controlled air conditioned culture room, under the light dark period of 16:8 h (L/D) at 25±20C, light dark period of 6:18 h (L/D) at 25 ± 20C and monochromatic light of 16:8 h (L/D). Maximum amount of Chl a was seen in the light dark period of 16:8 h (L/D) i.e, 4.4 μgmL-1 on 9th day of the experiment, Chl b was found in 6:18 h (L/D) which is 8.3μgmL-1 on 14th day of the experiment and Carotenoids was found un-der the light dark period of 16:8 h (L/D) which is 7.7 μgmL-1 on the 13th day of the study and highest number of Cells mL-1 was seen in 16:8 h (L/D). In monochromatic light, highest amount of Chl a was seen in Yellow light, i.e, 3.5 μg mL-1 on 17th day, Chl b in violet light which is 6.7 μgmL-1 on 13th day of study and Carotenoids in red light on 15th of study and highest no. of cells mL-1 (10x104 ) was found in red light condition.

Keywords: Haematococcus pluvialis; astaxanthin; ketocarotenoid; Carotenoids.