School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, China.
National Engineering Research Center of Corn Deep Processing, Jilin COFCO Biochemistry Co., Ltd., Changchun, China.
Biotechnol Bioeng. 2022 Sep;119(9):2471-2481. doi: 10.1002/bit.28152. Epub 2022 Jun 14.
Filamentous fungi occupy a uniquely favorable position in the bioproduction of organic acids. Intracellular stress is the main stimulator in filamentous fungi to produce and accumulate organic acids with high flux. However, stress can affect the physiological activities of filamentous fungi, thereby deteriorating their fermentation performance. Herein, we report that peptide supplementation during Rhizopus oryzae fermentation significantly improved fumaric acid production. Specifically, fumaric acid productivity was elevated by approximately 100%, fermentation duration was shortened from 72 to 36 h, while maintaining the final titer. Furthermore, transcriptome profile analysis and biochemical assays indicated that the overall capabilities of the stress defense systems (enzymatic and nonenzymatic) were significantly improved in R. oryzae. Consequently, glycolytic metabolism was distinctly enhanced, which eventually resulted in improved fumaric acid production and reduced fermentation duration. We expect our findings and efforts to provide essential insights into the optimization of the fermentation performance of filamentous fungi in industrial biotechnology and fermentation engineering.
丝状真菌在有机酸的生物生产中占据着独特的有利地位。细胞内应激是丝状真菌产生和积累具有高通量有机酸的主要刺激物。然而，应激会影响丝状真菌的生理活动，从而恶化其发酵性能。在此，我们报告肽补充在米根霉发酵过程中显著提高了延胡索酸的产量。具体而言，延胡索酸的生产力提高了约 100%，发酵时间从 72 小时缩短至 36 小时，而最终浓度保持不变。此外，转录组谱分析和生化分析表明，米根霉的应激防御系统（酶和非酶）的整体能力显著提高。因此，糖酵解代谢明显增强，最终导致延胡索酸产量提高，发酵时间缩短。我们希望我们的发现和努力为优化丝状真菌在工业生物技术和发酵工程中的发酵性能提供重要的见解。
