Abstract

Sulfur limitation is a frequently exploited method for inducing lipid accumulation in microalgae. However, there is little understanding of the underlying mechanism of this process. Hence, a study was conducted to determine the effects of sulfur limitation on nitrogen and sulfur uptake, lipid production strategies, and photosynthetic physiological characteristics of Scenedesmus acuminatus. A low sulfur concentration (0.076 mM; 0.25S group) decreased nitrate reductase activity and inhibited nitrogen absorption. The highest lipid productivity was obtained in the 0.75S (0.229 mM) group (221.93 mg L−1 day−1), significantly higher than that of the 0.5S (0.153 mM) and 0.25S groups (p < 0.05). Acetyl-coenzyme A carboxylase (ACCase) activity was upregulated in the 0.25S group to promote the accumulation of lipid and fatty acids, and generated the maximum lipid and fatty acid content (47.27% and 43.98% of dry weight, respectively). An important supplementation of energy for lipid accumulation under low-sulfur conditions is to drive a higher proportion of cyclic electron flow. Superoxide dismutase and peroxidase activities and malondialdehyde content increased at lower sulfur concentrations, indicating the elevated antioxidant activity of S. acuminatus.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.