Effects of gamma radiations on growth and photosynthetic pigments in Dunaliella salina
摘要
Dunaliella salina is a unicellular green alga inhabiting hypersaline environments such as salt evaporation ponds as well as high salt lakes and known for its excellent antioxidant and nutritional efficacy. The current study aims to evaluate the effect of different doses of ionizing gamma radiations on different parameters of Dunaliella salina. The analysed parameters include growth in the form of optical density and photosynthetic pigments chlorophyll (chlorophyll a, chlorophyll b and total chlorophyll a + b) as well as carotenoid content. The results of the study show that treatment of algae with gamma rays for different time points (5 min, 10 min, 15 min, 20 min, 25 min and 30 min) from a distance of 5.5 cm and 10.5 cm and subculturing of algae for a period of 0 week, 1 week, 2 weeks, 3 weeks, 4 weeks and 5 weeks respectively led to a significant increase in algal biomass. Furthermore, in all these cases, the algal chlorophyll content (chlorophyll a, chlorophyll b and total chlorophyll a + b) was observed to decrease. Nevertheless, carotenoid production was found to be significantly increased in Dunaliella salina on treatment with all the doses of gamma radiations and at all the studied time points up to 5th week. It declined in the days to come because of reduced growth. The results indicates that lower doses of gamma rays have a positive impact on carotenoid content.