OPTIMIZATION OF SALINITY AND INOCULUM DENSITY ON LIPID PRODUCTION FROM SCENEDESMUS SP. IN TWO-STEP CULTIVATION WITH RESPONSE SURFACE METHODOLOGY (RSM) APPROACH

• Main Author: Rahel Limawan, Jane
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/83007
• Institution: Institut Teknologi Bandung

In this study, Scenedesmus sp. was cultivated using a two-step cultivation method. In the first stage, Scenedesmus was cultured with the addition of inorganic carbon in the form of CO2 for the first three days. Subsequently, in the second stage, Scenedesmus sp. was cultivated with the addition of organic carbon in the form of glucose at 24 g.L-1 . The cultivation conditions varied by inoculum density and salinity during the second stage. Inoculum density variations were log 6.5, log 7, and log 7.5 cells/mL, while salinity variations used were 0.5, 1, and 2% (w/v). The Response Surface Methodology (RSM) was used for data collection, and response optimization was performed using a response optimizer with Minitab software. This research aimed to determine the stochastic equation to be used for optimizing the inoculum density and salinity variations that would enhance lipid production from Scenedesmus sp. Based on the study, inoculum density and salinity significantly influenced the response variables such as sugar consumption rate (g.L-1 .day-1 ), maximum biomass (g), and lipid concentration (% w/w). RSM analysis indicated that inoculum density positively correlated with lipid concentration (% w/w) and maximum biomass production (g.L-1 ). The optimal inoculum density and salinity, determined through response optimization and stochastic equation, to enhance maximum biomass and lipid concentration (% w/w) were log 6.99 cells.mL-1 and 2% respectively. These values resulted in a maximum biomass of 1,4 g.L-1 and a lipid concentration of 61.8% from Scenedesmus sp.