1-32: Statistical optimization of medium compositions toward butanol production from glycerol using Clostridium pasteurianum DSM525

 In this study, the medium composition for butanol production from glycerol by Clostridium pasteurianum DSM525 was optimized using response surface methodology (RSM). It was found that a pattern of butanol and 1,3-propanediol (1,3-PDO) production was significantly dependent on the concentration of ammonium sulfate. Also, the addition of sodium butyrate was found to enhance butanol production, but not 1,3-PD. A full factorial design (FFD) with three variables (glycerol as a carbon source, sodium butyrate and (NH₄)₂SO₄) were applied to identify which variables have significant effects on butanol production. After FFD experiment, glycerol, sodium butyrate, and (NH₄)₂SO₄ were identified as the factors for butanol production at a 95% significant level by analysis of variance (ANOVA). Steepest ascent experiments were applied to estimate the optimal region of the three factors and the central composite experimental design (CCD) was adopted to find a quadratic regression model and determine optimized values of three factors for butanol production. Based on our results, the optimized medium for butanol production was far different from that for 1,3-PDO production, making it possible to control a main product of fermentation by changing medium compositions.