ENIVRONMENT ASIA

Volume 12, No. 01, Month JANUARY, Year 2019, Pages 1 - 10

Optimization of biomass and oil production of scenedesmus obliquus grown in photobioreactor

Farouk K. El-Baz1, and Sayeda M. Abdo

Abstract Download PDF

The aim of this study was to grow Scenedesmus obliquus using vertical photobioreactor (PBR) and examine the oil production capacity of Scenedesmus obliquus grown under nitrogen repletion and starvation conditions. The volume of PBR was 4000 liters as a demo unit with the facility of computerized controlled system. Three dilution rates (0.125%, 0.18%, and 0.25%) were applied. The results showed that, the maximum biomass achieved with the highest dilution rate (0.25%) was 43.2 g /m2.day. This was detected when the dry weight was 2.1 g/L with consuming about 62.5 ≈ g/m2/day of CO2. The maximum oil content reached to 26%±0.23 after 29 days under nitrogen repletion conditions. However, under nitrogen starvation, the oil content was dramatically increased and reached to 41.9%±0.6 after 8 days. Fatty acids profile showed that, both saturated and unsaturated were detected. The major saturated fatty acids were palmitic (C:16:0) and stearic (C:18:0). The unsaturated fractions were detected as palmetoleic (C:16:1), oleic (C:18:1), linoleic (C:18:2) and linolenic acids (C:18:3). The fatty acids with four or more double ponds were not detected. Total saturated fatty acids represented 60.47% and 67.43% under nitrogen repletion and nitrogen starvation respectively. Therefore, nitrogen content not only affects oil content but also affects oil fractions.

Keywords

Photobioreactor; Scenedesmus obliquus; Biomass; Dilution rate; Oil enhancement

---