Haematococcus lacustris
Haematococcus pluvialis, a unicellular freshwater microalga, has drawn significant scientific attention due to its potential as a natural resource of the high-value carotenoid astaxanthin. Astaxanthin is known as one of the most powerful naturally occurring antioxidants and a natural food colorant, and thus is of great commercial importance in nutraceutical and aquaculture industries. In H. pluvialis cells, astaxanthin is present in the form of mono- or di- fatty acyl esters is the major ketocarotenoid accumulated under various stress conditions, like nutrient deprivation, high irradiation and high salt concentrationditions. Upon exposure to the stress conditions, the green motile flagellated and non-motile palmella forms of H. pluvialis cells are rapidly transformed into the resting cells, called haematocysts or aplanospores, accompanied by massive accumulation of astaxanthin in cytosolic lipid bodies, making the cells a distinct red color. 
strain
UTEX 2505