Department of Food Science and Biotechnology, Sungkyunkwan University (SKKU), 2066 Seobu-ro, Jangan-gu, Suwon 16419, Republic of Korea.
Department of Food Science and Biotechnology, Sungkyunkwan University (SKKU), 2066 Seobu-ro, Jangan-gu, Suwon 16419, Republic of Korea.
Enzyme Microb Technol. 2020 Jan;132:109395. doi: 10.1016/j.enzmictec.2019.109395. Epub 2019 Aug 10.
RNA-guided genome engineering technologies have been developed for the advanced metabolic engineering of microbial cells to enhance the production of value-added chemicals in Corynebacterium glutamicum as an industrial host. Here, we described the biotransformation of xylose to glycolate using engineered Corynebacterium glutamicum, a well-known industrial amino acid producer. A synthetic pathway involving heterologous D-tagatose 3-epimerase and L-fuculose kinase/aldolase reactions was introduced in C. glutamicum, resulting in 9.9 ± 0.01 g/L glycolate from 20 g/L xylose at a yield of 0.51 g/g (equal to 1.0 mol/mol). Additional glyoxylate reduction pathway developed by CRISPR-Cas12a recombineering has been introduced and attempted to increase the maximum theoretical molar yield of 2.0 (mol/mol). Due to the limitation of the CRISPR-Cas12a recombineering with TTTV PAM sites, advanced CRISPR-Cas systems were suggested for the next-round metabolic engineering for improving the glycolate yield to overcome the current genome-editing tool for metabolic engineering in C. glutamicum.
RNA 引导的基因组工程技术已被开发用于微生物细胞的高级代谢工程，以提高谷氨酸棒杆菌作为工业宿主生产增值化学品的能力。在这里，我们描述了利用工程化谷氨酸棒杆菌将木糖生物转化为乙醇酸的过程，谷氨酸棒杆菌是一种著名的工业氨基酸生产菌。在谷氨酸棒杆菌中引入了涉及异源 D-塔格糖 3-差向异构酶和 L-岩藻糖激酶/醛缩酶反应的合成途径，从而使 20 g/L 的木糖转化为 9.9 ± 0.01 g/L 的乙醇酸，产率为 0.51 g/g（相当于 1.0 mol/mol）。通过 CRISPR-Cas12a 重组酶工程开发了额外的乙醛酸还原途径，试图将最大理论摩尔产率提高到 2.0（mol/mol）。由于 TTTV PAM 位点的 CRISPR-Cas12a 重组酶的限制，建议使用先进的 CRISPR-Cas 系统进行下一轮代谢工程，以提高乙醇酸的产量，从而克服目前用于谷氨酸棒杆菌代谢工程的基因组编辑工具的限制。
