Effects of Four Organic Carbon Sources on the Growth and Astaxanthin Accumulation of Haematococcus lacustris

The microalga Haematococcus lacustris has a complex life cycle and a slow growth rate, hampering its mass cultivation. Culture of microalgae with organic carbon sources can increase the growth rate. Few studies have evaluated the effects of organic carbon sources on H. lacustris. We compared the vegetative and inductive stages of H. lacustris under autotrophic and mixotrophic conditions using four organic carbon sources: sodium acetate, glycerol, sodium gluconate, and ribose, each at various concentrations (0.325, 0.65, 1.3, and 2.6 g/L). The cell density was increased by 1.3 g/L of glycerol in the vegetative stage. The rapid transition to the inductive stage under nitrogen-depletion conditions caused by 1.3 or 2.6 g/L sodium acetate promoted the accumulation of astaxanthin. The production of astaxanthin by H. lacustris in mass culture using organic carbon sources could increase profitability.