State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211816, PR China.
State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211816, PR China.
J Biotechnol. 2018 Jun 20;276-277:1-9. doi: 10.1016/j.jbiotec.2018.03.015. Epub 2018 Mar 24.
The efficiency of current methods for industrial production of citric acid is limited. To achieve continuous citric acid production with enhanced yield and reduced cost, immobilized fermentation was employed in an Aspergillus niger 831 repeated fed-batch fermentation system. We developed a new type of material (PAF201), which was used as a carrier for the novel adsorption immobilization system. Hydrophobicity, pore size and concentration of carriers were researched in A. niger immobilization. The efficiency of the A. niger immobilization process was analyzed by scanning electron microscopy. Then eight-cycle repeated fed-batch cultures for citric acid production were carried out over 600 h, which showed stable production with maximum citric acid concentrations and productivity levels of 162.7 g/L and 2.26 g L h, respectively. Compared with some other literatures about citric acid yield, PAF201 immobilization system is 11.3% higher than previous results. These results indicated that use of the new adsorption immobilization system could greatly improve citric acid productivity in repeated fed-batch fermentation. Moreover, these results could provide a guideline for A.niger or other filamentous fungi immobilization in industry.
目前工业生产柠檬酸的方法效率有限。为了实现产率提高和成本降低的连续柠檬酸生产，固定化发酵被应用于黑曲霉 831 重复分批发酵系统中。我们开发了一种新型材料（PAF201），用作新型吸附固定化系统的载体。研究了载体的疏水性、孔径和浓度在黑曲霉固定化中的作用。通过扫描电子显微镜分析了黑曲霉固定化过程的效率。然后进行了长达 600 小时的 8 个周期重复分批培养生产柠檬酸，结果显示稳定生产，最大柠檬酸浓度和产率分别达到 162.7 g/L 和 2.26 g/L·h。与其他一些关于柠檬酸产率的文献相比，PAF201 固定化系统比以前的结果提高了 11.3%。这些结果表明，使用新型吸附固定化系统可以大大提高重复分批发酵中的柠檬酸产率。此外，这些结果可为工业中黑曲霉或其他丝状真菌的固定化提供指导。
