Background: Scenedesmus obliquus, a green unicellular chlorophycean microalga, is
well-established as a lipid and biomass production platform. The nutrient starvation strategy is
considered as a robust platform for lipid production from different microalgal strains.
Objective: The study aimed to analyse the influences of sulfur starvation on the growth rates, and
also biomass and lipid production and composition in a naturally isolated strain of S. obliquus.
Methods: The BG-11 culture medium was utilized for preservation and microalgal growth. To
monitor the cell growth rates, two different methods, including direct cell counting and also dry
cell weight measurement were used. The study was conducted in 28 days composed of two distinct
growth modes as 10 days of sulfur-rich and 18 days of sulfur starved media.
Results: The studied S. obliquus strain displayed higher lipid and carbohydrate production levels
(34.68% and 34.02%) in sulfur starved medium compared with the sulfur-rich medium (25.84%
and 29.08%). Nevertheless, a noticeable reduction (51.36%) in biomass contents and also in cell
growth rates (63.36%) was observed during sulfur starvation. The investigated strain was composed
of some important fatty acids with potential applications as food, feed and biodiesel.
Conclusion: The observed results implied the possibility of the sulfur starvation strategy to increase
lipid production in S. obliquus strain. Besides, the available data from recently published
patents reveals the promising potential of the identified lipids from S. obliquus in this study for
bioenergy production and other biotechnological purposes.