Optimization of astaxanthin accumulation in Haematococcus lacustris in a photobioreactor system

Astaxanthin is a highly sought keto-carotenoid with numerous health advantages and can either be produced naturally or synthetically. Natural astaxanthin outperforms synthetic by 50-fold, coenzyme-Q10 by 100-1000, and vitamin E by 500-fold in antioxidant and anti-inflammatory properties. Thus, natural astaxanthin remains potent that can be used as a sustainable-safe substitute for synthetics in the cosmetics, nutraceutical, and functional-food industries. Haematococcus is one of the most preferred genus for astaxanthin accumulation. In this study, the less-studied Haematococcus lacustris CCAP 34/6 strain was evaluated for optimal astaxanthin accumulation, and the obtained extract was presented as the final product in encapsulated form. To achieve this, light, temperature, growth medium and sonication conditions were evaluated under titles divided into two main groups: green and red phases, considering the unique life cycle of the strain. The green phase studies demonstrated a 308.21% increase in biomass in 3N:BBM medium under gradual blue-red-light at 23°C, whereas the red phase studies showed the most rapid astaxanthin accumulation in BG11-N medium at 28°C. Following the acquired data, a biomass concentration of 2.02 g/L and an astaxanthin yield of 2.1% were achieved after large-scale-cultivation in a 6L flat panel photobioreactor. Optimum encapsulation conditions were determined and edible beads with 4 mm and 8 mm diameters containing 1 mg of pure astaxanthin were produced. Overall, the findings of this comprehensive thesis study shed light on astaxanthin production from H. lacustris CCAP 34/6 by creating optimal growth conditions and extended to the final encapsulated product.