National Energy R&D Center for Biorefinery, Beijing University of Chemical Technology, 100029 Beijing, China.
National Energy R&D Center for Biorefinery, Beijing University of Chemical Technology, 100029 Beijing, China.
Bioresour Technol. 2023 Dec;390:129865. doi: 10.1016/j.biortech.2023.129865. Epub 2023 Oct 11.
N-acetylglucosamine (GlcNAc) is significant functional monosaccharides with diverse applications in medicine, food, and cosmetics. In this study, the GlcNAc synthesis pathway was constructed in Corynebacterium glutamicum and its reverse byproduct pathways were blocked. Simultaneously the driving force of GlcNAc synthesis was enhanced by screening key gene sources and inhibiting the GlcNAc consumption pathway. To maximize carbon flux, some competitive pathways (Pentose phosphate pathway, Glycolysis pathway and Mannose pathway) were weakened and the titer of GlcNAc reached 23.30 g/L in shake flasks. Through transcriptome analysis, it was found that dissolved oxygen was an important limiting factor, which was optimized in a 5 L bioreactor. Employing optimal fermentation conditions and feeding strategy, the titer of GlcNAc reached 138.9 g/L, with the yeild of 0.44 g/g glucose. This study significantly increased the yield and titer of GlcNAc, which lay a solid foundation for the industrial production of GlcNAc in C. glutamicum.
N-乙酰葡萄糖胺（GlcNAc）是一种重要的功能单糖，在医学、食品和化妆品领域有广泛的应用。本研究在谷氨酸棒杆菌中构建了 GlcNAc 合成途径，并阻断了其逆向副产物途径。同时，通过筛选关键基因来源和抑制 GlcNAc 消耗途径来增强 GlcNAc 合成的驱动力。为了最大限度地提高碳通量，削弱了一些竞争途径（戊糖磷酸途径、糖酵解途径和甘露糖途径），并在摇瓶中使 GlcNAc 的浓度达到 23.30 g/L。通过转录组分析，发现溶解氧是一个重要的限制因素，在 5 L 生物反应器中对其进行了优化。采用最佳发酵条件和补料策略，GlcNAc 的浓度达到 138.9 g/L，葡萄糖得率为 0.44 g/g。本研究显著提高了 GlcNAc 的产率和浓度，为谷氨酸棒杆菌中 GlcNAc 的工业化生产奠定了坚实的基础。
