Rapid neutral lipid accumulation of the alkali-resistant oleaginous Monoraphidium dybowskii LB50 by NaCl induction

NaCl is an effective inducer of lipid accumulation in freshwater microalgae, but little is known on whether the enhanced lipid components are desired. To address this issue, Monoraphidium dybowskii LB50 from a freshwater habitat was selected, cultivated, and subjected to NaCl induction at different scales outdoors. Results showed that the optimal salt concentration reduced glycolipid (GL) content, as well as enhanced neutral lipid (NL) and phospholipid (PL) contents. Moreover, GL was preferentially converted to NL at 20 g L−1 NaCl. Total lipid and NL contents respectively increased to 41.7% and 17.48% in 1 d. The highest NL productivity was also achieved at both the 5 L (24.13 mg L−1 d−1) and 140 L (13.05 mg L−1 d−1, 3.43 g m−2 d−1) scales. These results suggest that NL accumulated effectively and rapidly at different scales, indicating that this strategy has broad application prospects for the scale-up cultivation of oily algae.