Optimization of butanol production of Clostridium pasteurianum using response. Surface methodology

The optimization of fermentation conditions for converting glycerol to butanol was studied with Clostridium pasteurianum DSM525, which is known to convert glycerol to butanol and 1,3-propanediol (1,3-PD). Based on one-factor-at-a-time studies, pH, glycerol concentration, and the addition of co-substrate such as butyrate significantly influenced cell growth and butanol production by C. pasteurianum DSM525 in batch cultures. When 2-(N-Morpholino)ethanesulfonic acid (MES) was added to reduce pH drop during batch fermentations, butanol production was higher than 1,3-PD production without MES addition. However, butanol concentration was lower than 1,3-PD. The addition of co-substrate, such as butyrate, enhanced the production of butanol by > 50%. The concentration of carbon source, glycerol, also significantly affected cell growth and butanol production. The concentration of glycerol and butyrate, and ph were the three important variables to impact butanol production of C. pasteurianum DSM525. Further screening experiments will be performed to identify other important variables that significantly influence butanol production of C. pasteurianum DSM525. This is an abstract of a paper presented at the 8th World Congress of Chemical Engineering (Montréal, Quebec, Canada 8/23-27/2009).