Research Article: Optimization of production and antioxidant activity of fucoxanthin from marine haptophyte algae, Isochrysis galbana

This study compared the biomass production, fucoxanthin production and antioxidant capacity of the fucoxanthin from the marine haptophyte algae, Isochrysis galbana under different nitrogen concentrations. At first step in the salinity test, I. galbana could grow in ۲۰‰ and ۳۵‰ but the ۳۵‰ salinity was optimal. At second step, five different nitrogen concentrations (N-NO۳) of ۲, ۴, ۸, ۱۲ ۱۲ mM, at the salinity of ۳۵‰, were investigated. Algal cell density increased as nitrogen concentrations increased, but a low growth rate occurred in the culture with the highest nitrogen concentration (۱۲ mM). The maximum cell density of ۷۲×  and the maximum amount of fucoxanthin (۱۸.۱ mg g-۱) was obtained in I. galbana cultured in media containing four mM nitrogen (N-NO۳). The purified fucoxanthin exhibited strong antioxidant properties, with the effective concentration for ۵۰% scavenging (EC۵۰) of ۱, ۱-dihpenyl-۲-picrylhydrazyl (DPPH) radical, being ۰.۲ mg/ml. This study suggests that the production and fucoxanthin concentration of I. galbana can be improved using nitrogen-replete culture in ۳۵‰ salinity. Also under this condition this microalgaecan be a commercial source of fucoxanthin for human health and nutrition.

Keywords:

Isochrysis galbana , Culture , Nitrogen replete , Salinity , Fucoxanthin.