OPTIMIZATION OF INOCULUM CONCENTRATION AND PH ON LIPID PRODUCTION FROM RHODOTORULA TORULOIDES USING TWO-STAGE CULTIVATION WITH RESPONSE SURFACE METHODOLOGY

• Main Author: Pascani Silalahi, Clarissa
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/83129
• Institution: Institut Teknologi Bandung

Lipids are one of the beneficial components in living organisms. Currently, lipids are widely used in the pharmaceutical and nutraceutical industries. Many studies are developing lipids to produce biodiesel, supplements, bioethanol, carotenoids and so on. Rhodotorula toruloides is a type of yeasts that are able to synthesize high amounts of lipids up to 70% of its dry weight. This yeast has the advantage of being able to reproduce quickly. Optimization of the fermentation conditions from R. toruloides still needs to be adjusted to obtain maximum results. One of the strategies used to increase lipid production is two-stage cultivation. This study aims to determine the optimum pH variation and inoculum concentration for producing lipid from R. toruloides cultivated in palm sugar in batch mode for 120 hours of cultivation. The optimum lipid yield, biomass production rate, and maximum cell dry weight based on the optimum conditions of the prediction model will then be determined as well. In this study, the inoculum concentration was varied to 10 cells/mL. While the pH value was varied to 5, 6.5, and 8. The control variable used was the C/N ratio of 15.657 g/L. The C/N ratio value was achieved by adding ammonium sulfate to the cultivation medium. The optimum conditions are predicted to be obtained at a C/N ratio of 15.657 g/L; pH 5; and an inoculum concentration of 10 6 7 , 10 8 , and 10 cells/mL. Based on these predicted optimum conditions, the biomass production rate, maximum cell dry weight, and lipid yield obtained were 0,061 g/L.hr, 9,454 g/L, and 47,817% (w/w), respectively.