Photoperiod influences endogenous indoleamines in cultured green alga <i>Dunaliella bardawil</i>

Abstract

Effect of light intensity and photoperiod on growth, indoleamines and carotenoid production was studied in unicellular green algae <i style="">D</i>.<i style=""> bardawil</i>. Maximum biomass and carotenoid contents were found when cultures were grown in light (intensity of 2.0 Klux) at a photoperiod of 16/8h light and dark cycle. There was a profound influence of tested photoperiod conditions of light:dark viz. 8:16, 10:14, and 12:12 hr, continuous light on indoleamines (SER and MEL) production as estimated by HPLC and confirmed by mass spectral data obtained from LC-MS-ESI studies. Serotonin level increased from 908 to 1765 pg/g fresh wt with increase in light duration and melatonin level increased from 267 to 584 pg/g fresh wt during increase in dark phase. Carotenoids production was high in continuous light than other tested conditions.<b style=""></b>