Chemical induction of polyploidy increases astaxanthin accumulation capacity in the microalgae Haematococcus lacustris (Gir.-Chantr.) Rostaf

The worldwide-distributed microalgae Haematococcus lacustris (Gir.-Chantr.) Rostaf is considered the best producer of the anti-oxidant compound astaxanthin, a pigment 50 times more active than vitamin E, with important uses in nutraceutical and pharmacy industries. Nevertheless, Haematococcus accumulates a small proportion of this pigment within the cells, requiring further enhancement for its industrial use. The artificial induction of polyploidy on these species was attempted by using colchicine. The induction results generate one strain producing 33% more astaxanthin than the original strain under laboratory conditions (1.94% vs 2.59%, 150 mL volume) and 60% more astaxanthin in semi-industrial conditions (1.82% vs 2.91%, 3.500 L raceways). Additionally, it was determined that both cell volume and DNA content were increased in the polyploid strain, maintaining intact their capacity for astaxanthin extraction. This highlights a future industrial use for this strain and the potential use of polyploidization to enhance secondary metabolite production for other microalgae of commercial interest.