Effects of Xanthophyllomyces dendrorhous on cell growth, lipid, and astaxanthin production of Chromochloris zofingiensis by mixed culture strategy

The alga Chromochloris zofingiensis and the yeast Xanthophyllomyces dendrorhous are typical microorganisms which can accumulate high-value astaxanthin and lipid simultaneously. This study investigated the synergistic effects of X. dendrorhous on the cell growth, lipid, and astaxanthin production of C. zofingiensis by a mixed culture approach. Compared to the pure culture of C. zofingiensis, enhanced lipid and astaxanthin production were obtained in the mixed culture. The maximum astaxanthin and lipid yield achieved in the mixed culture with the ratio of 3:1 (algae to yeast) were 5.50 mg L-1 and 2.37 g L-1, respectively, which were 1.10- and 2.72-fold that of C. zofingiensis monoculture. Additionally, lipid obtained from the mixed culture had a plant oil-like fatty acid composition. This study provides a new insight into the integration of natural astaxanthin production with microbial lipid.