微生物发酵法生产1,3-丙二醇的常用方式是批式流加发酵,但是发酵时间较长,产物的生产强度较低,而连续发酵生产1,3-丙二醇,通过物料不断流动使发酵达到动态平衡,可有效提高生产强度。该文以已建立的批式发酵动力学模型为基础,对克雷伯氏肺炎杆菌(Klebsiella pneumoniae HR526)连续发酵生产1,3-丙二醇的工艺进行了研究,优化得到了使得产物浓度最大的稀释率参数,并分析比较了不同稀释率条件下的单级和多级连续发酵的实验结果。结果表明,最佳的连续发酵方式是二级连续发酵,总稀释率为0.028 h-1时产物浓度达到68.11 g/L,生产强度达到1.89 g/(L·h),与48 h的批式流加发酵相比,生产强度提高了27.7%。

Fed-batch fermentation is a conventional process for fermentative production of 1,3-propanediol,but the productivity is relatively low.By contrast,continuous fermentation can obtain a relatively high productivity since dynamic equilibrium is achieved and 1,3-propanediol can be produced steadily at a high rate.In this work,fermentative production of 1,3-propanediol with Klebsiella pneumoniae by several continuous fermentation processes was studied,and the operational dilution rates were optimized in order to get a high product concentration.The experimental results of single and multiple-stage continuous fermentations with different dilution rates were also compared.It was found that two-stage continuous fermentation was an favorable process for 1,3-PDO production with 1,3-PDO concentration of 68.11 g/L and productivity of 1.89 g/(L·h) at an overall dilution rate of 0.028 h-1.Compared with 48-hour fed-batch fermentation,the productivity was increased by 27.7%.