Large-scale production of astaxanthin from the green alga Haematococcus pluvialis

The green alga, Haematococcus pluvialis, is cultured in large-scale facilities for the production of the valuable Ketocarotenoid astaxanthin. The pigment is used for either coloring salmonid flesh or in the nutraceutical market as a strong antioxidant. It is proposed that astaxanthin production by Haematococcus can be achieved in a two-stage process, producing green biomass under optimal growth conditions (first 'green' stage) and exposing this biomass to adverse environmental conditions to induce the accumulation of astaxanthin (second 'red' stage). Although this technological approach appears rather simple, the mass culture of this alga outdoors is still a challenge, the main reason being frequent contamination with invading microorganisms such as green algae, protozoa, fungi and ciliates, resulting in unstable cultures, and in some cases even in total collapse of the cultures. This is due to the relative non-selective media used for the cultivation of the alga, and its relatively slow growth rate. To date, several commercial companies are involved in its mass production of this as a natural source of the Ketocarotenoid astaxanthin. Companies such as Fuji Chemicals and Alagtechnologies are using the so-called closed photobioreactors, while others such as Cyanotech and Mera use a combination of photobioreactors, closed systems for the green stage and open raceway ponds for the reddening process. Both of these approaches are discussed in terms of quality and production costs of the product. The potential market for this natural product, compared to the synthetic one, is addressed.