Kinetic model for 1,3-propanediol production from glycerol fermentation by Clostridium butyricum DSM 5431 in batch fermenter

摘要

3-propanediol (1,3-PD) has a wide range of potential uses, particularly as a monomer for the production of biodegradable polymers such as polytrimethylene terephthalate (PTT) and as an intermediate for the synthesis of heterocyclic compounds. 1,3-PD is a typical product from anaerobic fermentation of glycerol, a main by-product in biodiesel production processes. In this study, 1,3-PD production by Clostridium butyricum DSM 5431 was investigated in batch culture using different initial glycerol concentrations 60-120 g l -1 . The optimum conditions in 1 litre batch fermenter were found to be 80 g l -1 initial glycerol concentration, 33 °C, and pH 7.0.The maximum product concentration obtained was 44.75 g l -1 with the production yield of 0.77 (mol/mol). The inhibition effect of glycerol on the growth and productivity was observed at concentration higher than 80 g l -1 . The kinetic model for 1,3-PD production in batch fermentation was further developed. The most suitable cell model was the specific growth rate model which indicated multiple inhibition effects of glycerol, 1,3-PD, and butyric acid on Clostridium butyricum DSM 5431 growth. The model is useful for applications in fed-batch fermentation where substrate concentration can be controlled to prolong the production.