Succinic acid (1,4-butanedioic acid) is identified as one of important building-block chemicals. Xylose mother liquor is an abundant industrial residue in xylitol biorefining industry. In this study, xylose mother liquor was utilized to produce succinic acid by recombinant Escherichia coli strain SD121, and the response surface methodology was used to optimize the fermentation media. The optimal conditions of succinic acid fermentation were as follows: 82.62 g L-1 total initial sugars, 42.27 g L-1 MgCO3 and 17.84 g L-1 yeast extract. The maximum production of succinic acid was 52.09 ± 0.21 g L-1 after 84 h with a yield of 0.63 ± 0.03 g g-1 total sugar, approaching the predicted value (53.18 g L-1). It was 1.78-fold of the production of that obtained with the basic medium. This was the first report on succinic acid production from xylose mother liquor by recombinant E. coli strains with media optimization using response surface methodology. This work suggested that the xylose mother liquor could be an alternative substrate for the economical production of succinic acid by recombinant E. coli strains.
Keywords: Escherichia coli; fermentation; response surface methodology; succinic acid; xylose mother liquor.