Characterization of a new zeaxanthin producing strain of Chlorella saccharophila isolated from New Zealand marine waters

A fast growing strain of Chlorella saccharophila was isolated from the marine water of New Zealand and grown in heterotrophic conditions using glucose or glycerol as a carbon source. Biomass production was found to be higher in culture fed with glucose (2.14 ± 0.08 g L−1) as compared to glycerol (0.378 ± 0.04 g L−1). Lipid accumulation was similar for both carbon sources, at approximately 22% of dry cell weight. However, carotenoid yield was higher with glycerol (0.406 ± 0.0125 mg g−1) than with glucose (0.21 ± 0.034 mg g−1). Further optimization of the growth of the isolate gave maximal carotenoid production of 16.39 ± 1.19 mg g−1 total carotenoid, containing 11.32 ± 0.64 mg g−1 zeaxanthin and 5.07 ± 0.55 mg g−1 β-carotene. Comparison of various chemical and physical carotenoid extraction methods showed that ultrasonication was required for maximum extraction yields. The new strain has potential for biofuel, with carotenoid co-production.