若干因素对发酵法生产1,3-丙二醇的调控作用

利用一株新筛选的克雷伯氏肺炎杆菌(Klebsiella pneumoniae ZJU 5205)对发酵法生产1,3-丙二醇进行了研究,考察了 pH、溶氧及添加辅助底物葡萄糖对发酵过程的调控作用。实验结果表明,相比于未调控 pH 发酵,恒定 pH 值发酵得到的菌体浓度明显增高,甘油消耗加快,1,3-丙二醇的最终浓度以及甘油到丙二醇的转化率(Y_(P/S))明显提高,分别达16.39g/L和0.51mol/mol;厌氧发酵时的菌体浓度和甘油消耗速率均高于微氧发酵,但1,3-丙二醇最终浓度和转化率低于微氧发酵;添加葡萄糖为辅助底物能够有效促进菌体生长,但1,3-丙二醇最终浓度和转化率却低于以甘油为单一底物时的发酵结果。

Effects of Operation Parameters on Microbial Production of 1,3-Propanediol by Klebsiella Pneumoniae

Batch fermentations with Klebsiella pneumoniae ZJU 5205 screened recently were studied in order to determine the effects of pH,dissolved oxygen and glucose as cosubstrate on the production of 1,3-propanediol (1,3-PD).Results showed that both the final concentration (16.39 g/L) and mo- lar yield from glycerol to 1,3-PD (Y_(p/s)) (0.51 mol/mol) in the constant-pH fermentation were higher than those of the uncontrolled-pH fermentation,and the constant-pH ensured an enriched biomass and accelerated specific rate of glycerol consumption.Compared with results of the microaerobic fermenta- tion,the anaerobic fermentation favored cell growth and glycerol consumption,but its final concentra- tion and Y_(p/s) of 1,3-PD were lower than those of microaerobic fermentation.Finally,glucose as co- substrate had a positive effect on the growth of K.pneumoniae,while the final concentration and Y_(p/s) of 1,3-PD in the cosubstrate fermentation were lower than those of the single-substrate fermentation.