响应面优化木糖母液发酵产丁二酸

对产琥珀酸放线杆菌（Actinobacillus succinogenes）GXAS137发酵木糖母液产丁二酸的条件进行优化，探索利用废弃木糖母液合成高附加值丁二酸的可行性。首先通过Plackett-Burman实验设计确定影响丁二酸发酵的显著因子，然后采用最陡爬坡实验逼近各显著因子的最优区域，最后通过Box-Behnken实验设计确定各因子的最优水平。影响木糖母液发酵产丁二酸的显著因子及最优浓度分别为：木糖母液64.75g/L，玉米浆15.71g/L，碱式碳酸镁46.39g/L。在最优发酵培养条件下，丁二酸产量达到38.01g/L，比优化前提高了20.7%，与模型预测值（38.41g/L）基本一致。进一步利用2L发酵罐进行了放大试验，发酵72h丁二酸产量最高可达48.99g/L，较厌氧瓶发酵提高了28.9%，丁二酸得率为0.80g/g总糖。结果表明，采用低价的木糖母液作为底物，可为未来低成本、高效产业化生产丁二酸奠定坚实的基础。

Optimization of succinic acid fermentation from xylose mother liquor by response surface methodology

The conditions of succinic acid production by Actinobacillus succinogenes GXAS137 from xylose mother liquor were optimized to explore the feasibility in synthesis of high-value-added succinic acid from waste xylose mother liquor. First, the key medium components were identified by Plackett-Burman design experiment. Further optimization was run by Steepest Ascent method to rapidly approach the optimal region of the key medium components. Finally, the optimal levels of key medium components were achieved by Box-Behnken design experiment. The optimum concentration of key media components was as follows:xylose mother liquor 64.75g/L, corn steep liquor 15.71g/L, and Mg₂ (OH)₂CO₃ 46.39g/L, respectively. Under those conditions, 38.01g/L succinic acid was obtained, increasing by 20.7% after optimization and basically agreeing with the predicted value. Scale-up experiment was further implemented in a 2L stirred bioreactor, and up to 48.99g/L succinic acid was obtained within 72h, with a yield of 0.80g/g total sugar. Succinic acid increased by 28.9% compared with that of anaerobic bottles. The results showed that employing inexpensive xylose mother liquor as feedstock, could lay a solid foundation for future low-cost and efficient industrial production of succinic acid.