Impact of natural light on growth and biopigment profile of cyanobacteria Spirulina platensis.

Cyanobacteria are economically important microorganisms and good source of natural pigments such as chlorophyll, carotenoids and phycobilliproteins. The present research work showed the optimum combination of photophase and scotophase of Spirulina platensis on biomass and chlorophyll-a, carotenoids, phycocyanin, allophycocyanin, and phycoerythrin contents. The study revealed that among all six light conditions tested, the cultures placed at west facing window, receiving natural day light at temperature 30°C showed extremely significant higher biomass (O.D. 3.46 ± 0.17%) and biopigment accumulation Chlorophyll a 8.94 ± 0.43%, Carotenoid 1.62 ± 0.18%, phycocyanin 2.26 ± 0.14%, allophycocyanin 2.66 ± 0.18% and phycoerythrin 1.32 ± 0.31% as compared to the standard (Full day natural light), which might be beneficial for large scale production of biopigment.