CASSAVA PEEL POTENTIAL AS CARBON SOURCE FOR PUFA PRODUCTION BY ASPERGILLUS ORYZAE WITH VARIATION FOR CARBON CONCENTRATION AND C:N RATIO.

• Main Author: Aqila Hanif, Mohammad
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/86018
• Institution: Institut Teknologi Bandung

Polyunsaturated fatty acids or PUFAs are a collection of essential double stranded fatty acids that serves as a raw component in various industrial products such as food, health, and pharmacy. An alternative PUFA production method based on microbial lipids was used to fulfil the high market demand of this compound in a more sustainable and environmentally friendly fashion. One of the main challenges of said production method is the high production cost that resulted by the use of glucose as the main carbon source. Cassava peels have the potential to serve as a carbon source for lipid production by Aspergillus oryzae, one of many oleaginous fungi used in microbial lipid production. This study was done to evaluate the potential of cassava peel flour as a carbon source for lipid production by Aspergillus oryzae. Determination of the optimum composition (C:N ratio and carbon concentration) of the cassava peel medium was done to achieve this objective. Optimization of these factors were done by using the Central Composite Design of Response Surface Methodology, which consisted of 13 variation of C:N ratio (13.8, 20, 35, 50, 56.2) and carbon concentrations (1.2%, 2%, 4%, 6%, 6.8%) which was repeated twice. Total lipid and lipid yield from each variation was observed and used in the optimization process. Lipids produced from the optimised medium composition are then analysed using the GC-FID method to determine their fatty acid composition. The optimal cassava peel media composition was determined through RSM which contains carbon concentration of 3.4 % and a C:N ratio of 56:1. This composition produced lipids with a total amount of 41.9 mg / 50 mL medium and a lipid yield of 0.0149 g / g substrate. High C:N ratio in the media can increase the concentration of lipids accumulated by the fungi but may also inhibit biomass growth. Lipid production with the cassava peel media produced higher total lipid compared to the glucose media. It is predicted that the lower total lipid accumulation (26.7 mg) was caused by the low carbon concentration (1.23%) and the low C:N ratio (30:1) in the glucose media which inhibits biomass growth and reduces lipid accumulation of the fungi. The fungal lipid produced from the optimised media contains 50.5 % saturated fatty acids such as stearic and palmitic acids and 49.5% unsaturated fatty acids which consists of MUFAs such as oleic acid, and PUFAs which consists of linoleic, and linolenic acids. It can be concluded that with a cassava peel medium composition of a C:N ratio of 56 and a carbon concentration of 3.4%, a total lipid amount of 41.9 mg with a concentration of 0.8376 mg/mL of medium was produced, mainly consisting of stearic, linoleic, oleic, and palmitic acids. According to the research objective, the lipid production performance on the cassava peel medium proves that cassava peel has the potential to be an alternative substrate for Aspergillus oryzae in lipid production. However, further research is required to determine the robustness of the medium before it can fully substitute glucose as a carbon source for lipid production.