School of Bioengineering, Dalian University of Technology, Dalia, Liaoning 116024, PR China.
School of Bioengineering, Dalian University of Technology, Dalia, Liaoning 116024, PR China.
Bioresour Technol. 2020 Aug;310:123427. doi: 10.1016/j.biortech.2020.123427. Epub 2020 Apr 23.
A novel two-stage fermentation strategy was applied to produce xylitol and ethanol from the whole acid-pretreated corn cob slurry. The acid-pretreated corn cob was used without filtration and detoxification by the two-stage fermentation with the robust Kluyveromyces marxianus CICC 1727-5. In the first stage, xylose in the slurry after dilute acid pretreatment of lignocellulosic biomass was used to produce xylitol under micro-aeration conditions. In the second stage, simultaneous saccharification fermentation was carried out, and the ethanol was produced from glucose releasing from the solid. Important parameters, such as aeration rate, cellulase loading during xylose utilization and SSF fermentation were studied for best performance. The two-stage fermentation strategy removed the inhibition of glucose on xylose, and little xylose was left in the fermentation broth. Under the optimized condition, the maximum ethanol and xylitol concentration were 52 g/L and 24.2 g/L corresponding to the yield of 0.41 g/g and 0.82 g/g, respectively.
采用新型两段式发酵策略，利用木质纤维素酸预处理全浆，生产木糖醇和乙醇。该两段式发酵采用鲁氏接合酵母（Kluyveromyces marxianus）CICC 1727-5，无需过滤和解毒，直接利用酸预处理后的玉米芯全浆。在第一阶段，在微需氧条件下，利用木质纤维素生物量酸预处理后的浆液中的木糖生产木糖醇。在第二阶段，进行同步糖化发酵，利用固体释放的葡萄糖生产乙醇。研究了重要参数，如通气速率、木糖利用过程中的纤维素酶加载量和 SSF 发酵，以达到最佳性能。两段式发酵策略消除了葡萄糖对木糖的抑制作用，发酵液中几乎没有木糖残留。在优化条件下，最大乙醇和木糖醇浓度分别为 52g/L 和 24.2g/L，相应的得率分别为 0.41g/g 和 0.82g/g。
