Indian Journal of Science and Technology
Year: 2019, Volume: 12, Issue: 47, Pages: 1-9
Erly Marwani* and Ivana Kurniawan
Objectives: To develop an efficient Botryococcus sp. for high biomass and oil productivity with a fatty acid profile suitable for biodiesel. Methods and analysis: The culture of Botryococcus sp.was maintained in the modified Chu-13 medium at 16:8 light and dark cycle with 5,200 lux light intensity at 25°C and aerated with 1.5 L of air per minute. The nitrogen concentrations of the media varied, 5, 28, 55 (control), 350 mg L−1, with a constant concentration of phosphorous (44 mg L−1). For growth determination, Botryococcus sp. was harvested, dried, and weighed. Nitrogen consumption was measured by spectrophotometric methods. Oil was extracted from dried biomass of the algae using a soxhlet extractor (70°C, 4 hours), followed by methylation and analysis of fatty acids using gas chromatography. Findings: The results under these sets of experiments indicated that 350 mg N L−1 gave the maximal growth rate i.e. 0.24 g day−1 and the maximal biomass productivity i.e. 77.5 mg L−1 day−1. On the other hand, the maximal oil productivity of 5.03 ± 0.10 mg L−1 d−1 was obtained from medium containing nitrogen 55 mg L−1. The fatty acid profile of Botryococcus sp. oil showed a high amount of palmitic acid and oleic acid. Nitrogen concentrations of 5, 28, 55 (control) and 350 mg L−1 in the culture media resulted in 38.07%, 34.59%, 29.48%, 19.43% palmitic acid and 22.29%, 24.52%, 26.99%, 8.81% oleic acids respectively. These fatty acid profiles indicated that the Botryococcus sp. oil could be processed into biodiesel. Novelty: Growth, oil biomass content and fatty acid profiles of Botryococcus sp. cultures were affected by nitrogen concentration of the media. In this study, 55 mg N L−1 was the most efficient nitrogen concentration for maximal oil productivity with fatty acid content that met the requirements for conversion into biodiesel.
Keywords: Botryococcus Sp., Algal Oil, Fatty Acid, Nitrogen
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