초록
Lactobacillus reuteri is a potential strain for the production of 1,3-propanediol and lactic acid due to its good safety. The aim of this work was to study the inhibition of lactic acid and acetic acid during fermentation, and thus, to investigate the effect of their in situ removal on the growth and metabolism of L. reuteri. The analysis of metabolic flux showed that both of lactic acid and acetic acid severely inhibited the fermentation. Only 30.11mM and 66.85mM glucose were consumed in 24h under the initial concentration of 444mM lactic acid and 415mM acetic acid, respectively. The activity of the cell was dramatically decreased by the organic acid, furthermore, the production of 1,3-propanediol and lactic acid was impeded. The adsorption properties of anion exchange resin (D301G) were investigated to facilitate the removal of organic acid in situ during fermentation. The resin D301G was added at initial and during fermentation of 12h, respectively, which showed different function on the metabolism of L. reuteri. Initial addition of resin increased the biomass of fermentation, while the glucose consuming and the 1,3-propanediol producing did not change significantly. The resin added at 12h promoted the conversion of glycerol to 1,3-propanediol due to the NADH accumulation caused by the metabolic flux migration to acetic acid pathway, while the biomass decreased in small amount.