Nutrient composition of Chlorella spp. and Monodus subterraneus cultured in a bubble column bioreactor

The nutritional composition of two marine microalgae, Chlorella spp. and Monodus subterraneus, cultured in an outdoor bubble column photobioreactor used in batch mode was analyzed. Nutrients are reported at different microalgal growth phases. The proximate composition (moisture, crude protein, available carbohydrates and saponifiable oil), fatty acid and carotenoids at different growth stages were determined. On average, the biomass contained high amounts of protein in the two analyzed microalgae for all growth stages. Chlorella spp. biomass contained -linolenic acid as predominant fatty acid, while M. subterraneus biomass was rich in palmitic and eicosapentaenoic fatty acids, which reached a maximum EPA productivity at the exponential growth phase (65.0 mg L-1day-1). For both microalgae, carotenoid content was strongly influenced by the growth phase. Chlorella spp. biomass was found to be good sources of lutein and -carotene, while M. subterraneus biomass exhibited high amounts of neoxanthin and -carotene. A high carotenoid productivity was obtained for this microalgae at the stationary growth phase, with 19.4 mgL-1day-1. The results of this study clearly demonstrated the relevance of microalgae for potential use in functional foods, justifying their commercial production.