FERMENTATION OF RAW GLYCEROL TO 1,3-PROPANEDIOL BY NEW STRAINS OF CLOSTRIDIUM-BUTYRICUM

Industrial glycerol obtained through the transesterification process u sing rapeseed oil did not support growth of several strains of Clostri dium butyricum obtained from bacterial culture collections. Ten new st rains of C. butyricum were obtained from mud samples from a river, a s tagnant pond, and a dry canal. These new isolates fermented the commer cial glycerol and produced 1,3-propanediol as a major fermentation pro duct with concomitant production of acetic and butyric acids. Four of the ten isolates were able to grow on industrial glycerol obtained fro m rapeseed oil. One strain, C. butyricum E5, was very resistant to hig h levels of glycerol and 1,3-propanediol. Using fed-batch fermentation , 109 g L(-1) of industrial glycerol were converted into 58 g of 1,3-p ropanediol, 2.2 g of acetate and 6.1 g of butyrate per liter.