Erturk H1, Sudagidan M1, Yurda
Abstract
Microalga is known to have higher lipid contents and biodiesel efficiency than most plant oil sources e.g. palm oil. We studied the growth of Chlorella vulgaris at the photobioreactor in our laboratory. We aimed to use this photobioreactor of laboratory scale as feed stream to an open pond larger scale bioreactor for future work. Photobioreactor had three compartments which had separate controls for light and air circulation. Temperature was kept at 22°C-26°C. The circulation rate was 180 L/h. The light intensity was set at 16 hours on and 8 h off. The nutrient powder was dissolved in sterile water and the pH of the solution was 6.5-6.7. Inoculation of culture was performed aseptically. The algae culture was an original strain of Chlorella vulgaris. This specific culture was proposed for use as bioenergy due to high lipid content. Culture growth was maintained aseptically and samples were taken from the reactor periodically for microbial analysis. The continuous growth was achieved at the bioreactor without contamination for more than 9 months. Slurry was centrifuged, dried and algae biomass was obtained. Extraction of lipids of the dried algae was performed by Bligh and Dyer method Extracted lipid was subject to transesterification reaction for production of fatty acid methylesters (FAMES).The lipid contents of sample was analysed by GC-FID. The results for the lipid contents were: Palmitic acid: 28%, Linoleic acid: 26%, Heptadecanoic acid: 12%, Oleic acid: 10%, Palmitoleic acid: 3%, stearic acid: 5% and the rest is arachidic acid, myristic acid etc.