Study on Newly Isolated Dysmorphococcus Strains from Reunion Island as Potential Sources of High-Value Carotenoids

Area of Science:

• Biotechnology
• Microbiology
• Natural Products Chemistry

Background:

• Secondary carotenoids like astaxanthin and canthaxanthin possess significant biological activities, notably antioxidant properties.
• These xanthophylls are of increasing economic importance in human nutrition, food, health, cosmetics, animal feed, and aquaculture.

Purpose of the Study:

• To evaluate the feasibility of cultivating newly isolated *Dysmorphococcus* strains for the commercial production of astaxanthin and canthaxanthin.
• To assess the potential of these microalgal strains as a source of valuable carotenoids.

Main Methods:

• Isolation and cultivation of novel *Dysmorphococcus* strains from Reunion Island's biodiversity.
• Photobioreactor cultivation of selected strains under controlled environmental conditions.
• Biomass and carotenoid content analysis using spectrophotometric and chromatographic methods.

Main Results:

• All isolated *Dysmorphococcus* strains demonstrated the ability to produce and accumulate canthaxanthin and astaxanthin under stress conditions.
• A selected strain achieved maximum carotenoid-rich biomass concentrations of 4 g L^-1 dw and productivities of 0.055 g L^-1 d^-1 dw.
• The biomass yielded up to 1.2 mg g^-1 dw of canthaxanthin and 0.7 mg g^-1 dw of astaxanthin, primarily as monoesters.

Conclusions:

• The study confirms the potential of locally isolated *Dysmorphococcus* strains for producing natural astaxanthin and canthaxanthin.
• Current carotenoid productivities are lower than those reported for other microalgal species, indicating a need for further research.
• Optimization of cultivation and carotenogenesis induction processes is crucial for the commercial viability of these strains.