STUDY OF VARIOUS INITIAL NITROGEN CONCENTRATION ON LIPID CONTENT, PIGMENT CONTENT, AND FATTY ACID COMPOSITION OF Botryococcus braunii

• Main Author: KURNIAWAN (NIM : 11213024), IVANA
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/22646
• Institution: Institut Teknologi Bandung

The objective of this reasearch was to evaluate the effect of initial nitrogen concentration on lipid content, pigment content, fatty acid composition, and nitrogen consumption of Botryococcus braunii. The culture was maintained in modified Chu-13 medium at 16:8 light and dark cycle with 5,200 lux light intensity at 25oC and aerated with 1.5 liter air per minute. The added initial nitrogen concentration was 5 mg N/l; 28 mg N/l; 55.4 mg N/l (control); 350 mg N/l; dan 510 mg N/l respectively. B. braunii was cultured until the beginning of the stationary phase then filtered and dried to obtain dried biomass. Lipid was extracted with n-hexane from dried biomass using soxhlet (70oC, 4 hours), methylated, and then analyzed using gas chromatography to obtain the composition of fatty acid. Biomass growth, nitrogen level, chlorophyll content, and carotenoid content were analyzed using spectrophotometer. The result showed that the control culture obtained the highest biomass productivity (53.83 ± 4.82 mg l-1 day-1) but contained the lowest lipid content (3.23% dry weight). Meanwhile, the highest lipid content (10.24% dry weight) and biomass growth rate (0.19 ± 0.03 day-1) were obtained in the culture with initial nitrogen concentration of 5 mg N/l, followed by lower biomass productivity and lower pigment (chlorophyll and carotenoid) content than of the control culture. This indicates that the lipid production of B. braunii could be triggerred under nitrogen limited condition.The palmitic acid content in B. braunii culture with 5 mg N/l; 28 mg N/l; 55.4 mg N/l; 350 mg N/l; and 510 mg N/l were 38.07%; 34.59%; 29.48%; 19.43%; and 33.66%, while the oleic acid content were 22.29%; 24.52%; 26.99%; 8.81%; and 31.89% respectively. The fatty acid composition of all groups showed that B. braunii lipid was potential as a biodiesel source that could be used in a tropical area. <br /> <br />