两阶段控制甘油浓度提高1,3-丙二醇发酵水平

Enhancement of 1,3-Propanediol Production Using Two-Stage Glycerol Concentration Control Strategy

克雷伯氏菌(K lebsiella pneum on iae)分批发酵生产1,3-丙二醇(1,3-PD),根据菌体生长、产物生成和补料可将发酵过程分成4个阶段。不同阶段控制不同的底物浓度会对菌体生长和产物生成产生不同的影响。研究发现,菌体生长阶段(阶段II)底物浓度控制在6.0 g/L最适合菌体生长,产物主要生成阶段(阶段III)底物浓度控制在18.9 g/L最适合产物生成,菌浓可达7.83 g/L,最终1,3-PD的浓度为68.5 g/L,摩尔转化率为61%,生产强度为2.21 g/(L.h)。

According to cell growth, production formation and glycerol feed, the 1,3-propanediol （1,3- PD） fed-batch fermentation by Klebsiella pneumoniae can be divided into four different stages. The fermentation process is effected by the glycerol concentration at different stages. In the growth stage （phase II） of fermentation, the most appropriate concentration of gly-cerol for the cell growth is 6.0 g/L. Besides, under the control of glycerol concentration at 18. 9 g/L in the production main formation stage （phase III）, 1,3-PD is biosynthesized quickly. Therefore the new process of 1,3-PD production using twostage glycerol concentration control strategy was proposed. In this process, the biomass concentration, the mol yield of glycerol and the mol productivity are 7.83 g/L, 61% and 2.21 g/（L . h） respectively.