A novel process for the mixotrophic production of lutein with Chlorella sorokiniana MB-1-M12 using aquaculture wastewater

In this study, microalgal cultivation was applied as a feasible strategy for treating shrimp culture wastewater (SCW) from a shrimp farm in southern Tainan. Chlorella sorokiniana MB-1-M12 was first grown on BG-11 medium with 0.5% salinity, obtaining a biomass concentration and productivity of 4.35 g/L and 1.56 g/L/d, respectively. When 80% of BG-11 nutrients were added to 75% strength SCW, lutein content and productivity increased to 5.19 mg/g and 5.55 mg/L/d, respectively. A novel operation strategy involving periodic exchange of freshwater and SCW was designed for semi-continuous cultivation of MB-1-M12 strain for optimal biomass and lutein production. The average biomass concentration, productivity, lutein content, and productivity were 3.5 g/L, 1.3 g/L/d, 3.89 mg/g and 5.0 mg/L/d, respectively. Although microalgae have been considered as an alternative natural source of lutein, this work is among the earliest reports describing lutein production from microalgae cultivated with wastewater via a circular economy concept.