Astaxanthine from indigenous strains of Haematococcus pluvialis (ASTAXANTHINE)

Astaxanthin (a carotenoid) is used in fish and shrimp feed for aquaculture and is to date the most expensive raw material in its purified natural form. Can we produce astaxanthin in a cost efficient way by a suitable strain of Haematococcus pluvialis, a type of micro-algae? This project investigates the potential for cultivating local strains of Haematococcus pluvialis in our climate with high yields of astaxathin. We examine the intraspecific variation in  astaxanthin yield. Selected strains or a combination of strains are cultured to test the effect of upscaling. Furthermore, these batches are used in shrimp feed to investigate the intended effects of pigmentation and immunostimulation in rearing the tropical shrimp Litopenaeus vannamei.

We set up a collection of the micro-algae Haematococcus pluvialis, with a focus on local strains from different microhabitats in NW Europe. Isolates from this collection will be grown in the lab to evaluate carotenogenesis and growth under standard laboratory conditions. Some selected (mono/poly) cultures will be scaled up under moderate climatic conditions. We compare these cultures for growth rate and total production of astaxanthin. Finally, we process the biomass of these cultures in shrimp feed and test these in terms of bioavailability, pigmentation and immunostimulation in Litopenaeus vannamei.

Carotenoids are important components in the shrimp feed because of their vital role in the physiology and health of the shrimp. In addition, carotenoids like astaxanthin are responsible for the typical pink colour of shrimp after cooking. Consumers deem this colour to be a major quality characteristic of shrimp. In current breeding practice, carotenoids are therefore added to the shrimp feed, usually in the form of astaxanthin. The synthetic form of astaxanthin is forbidden in the commercial breeding of shrimps and the natural and purified form is very expensive (2000 USD per kg). A cheaper alternative, such as a Haematococcus pluvialis biomass cultured under moderate climatic conditions without extraction, would therefore be a suitable alternative.