Enhancing Docosahexaenoic Acid Production of Isochrysis galbana from Starch-Rich Food Processing Byproducts

Abstract

Leftover dough, a byproduct in steamed bread processing, is rich in starch, which is a carbohydrate source for microorganisms. Carbon and nitrogen are the two most abundant nutrients in the medium of Isochrysis galbana. In this study, the leftover dough hydrolysates were used as carbon resources for the cultivation of Isochrysis galbana for docosahexaenoic acid production under different NaNO3 concentrations. The results showed that hydrolysates and NaNO3 concentration affected cell growth and docosahexaenoic acid (DHA) accumulation significantly. The maximum biomass concentration of 4.18 g L−1 and maximum DHA yield of 341.3 mg L−1 were obtained with 50.0 mL L−1 hydrolysates. The DHA yield of Isochrysis galbana with 300.0 mg L−1 NaNO3 was 8.9-fold higher than that of the control. The results showed that the DHA production of Isochrysis galbana from starch-rich food processing byproducts was enhanced.