Effect of Some Organic Acids on Cell Growth and 1,3-Propanediol Production

To improve 1,3-propanediol production efficiency of Klebsiella pneumoniae,some organic acids(OA) are added in the fermentation process to investigate the effect of these organic acids on cell growth and production of 1,3-propanediol and other by-products.The results show that addition of OA can accelerate the cell growth:adding 0.2～0.5 g/L OA,the biggest optical density(OD) at 590 nm is 30% higher than reference point.But excess OA(1.0 g/L) will inhibit the growth of cell and the OD is 37% lower than reference point.Addition of OA can increase the production of 1,3-propanediol per cell:adding 0.2～0.5 g/L OA,1,3-propanediol concentration/OD is 3.8%～17.5% higher than reference point.Addition of OA can prompt the molar yield of 1,3-propanediol:adding 0.2～0.5 g/L OA,the maximal molar yield of 1,3-propanediol from glycerol reaches 0.81 h~(-1).When batch fermentation was carried out in 10 L fermentation medium in a 15 L fermenter for 48 h,the final mass concentration of 1,3-propanediol is 42.9 g/L and the average molar yield of 1,3-propanediol from glycerol is 64%.