OPTIMIZATION OF MEDIA NUTRITION FOR BIOSURFACTANT PRODUCTION BY BACILLUS SP. F7 USING RESPONSE SURFACE METHODOLOGY

• Main Author: Gusning Ati, Aulia
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/48586
• Institution: Institut Teknologi Bandung

One of the microbial bioproducts that can increase oil production in Microbial Enhanced Oil Recovery (MEOR) process is biosurfactant. Bacillus sp. F7 is known to produce biosurfactants and has the potential to be applied in MEOR, but needs further optimization to increase production affordability. Media optimization is one method that can be used to ameliorate biosurfactant production. Optimizing the nutrition can contribute to the production cost and the bioprocess economics. Therefore, this study aims to screen various carbon and nitrogen sources and optimize biosurfactant production by altering the carbon (C), nitrogen (N), and phosphorus (P) concentration using response surface methodology. To determine the best carbon and nitrogen, carbon sources consisted of molasses, POME, and glycerol and nitrogen sources in the form of urea, NH4Cl, and NH4NO3 are used. Carbon and nitrogen sources are selected based on biosurfactant dry weight and their ability to reduce interfacial surface tension (IFT). Central Composite Design was used as statistical method in response surface methodology to optimize the concentration of selected carbon, nitrogen, and phosphate sources (molasses 0.4-6% (w/v), urea 0.1-0.7% (w/v), and KH2PO4 0.1-0, 7% (w/v)) using Design Expert 11.0 software. This research was conducted with a batch system using the Stone Mineral Salt Solution medium which was added with carbon, nitrogen and phosphate sources as designed in this study. The parameters observed include the emulsification index and the ability to reduce the interfacial tension between oil and water. The results showed that molasses was the best carbon and urea was the best nitrogen source in producing biosurfactant by Bacillus sp. F7. The results of formulations based on composite designs analysis showed that the optimum concentration of nutrients was molasses 2.12% (w/v), urea 0.41% (w/v), and KH2PO4 0.01% (w/v) which was predicted to produce biosurfactants with emulsification index (Ei) of 60.61%.