代谢工程改造酿酒酵母合成葡萄糖二酸

Metabolic engineering of Saccharomyces cerevisiae for production of glucaric acid

摘要:

葡萄糖二酸是一种高附加值的有机酸，广泛用于食品、医药和化工领域。为获得生产葡萄糖二酸的微生物细胞工厂，通过共表达小鼠来源的肌醇加氧酶 (MIOX) 及恶臭假单胞菌来源的醛酸脱氢酶 (Udh)，在酿酒酵母Saccharomyces cerevisiae CEN.PK2-1C中构建了葡萄糖二酸合成途径，产量为 (28.28±3.15) mg/L。在此基础上，通过调控前体肌醇的合成途径，发现肌醇-1-磷酸合成酶 (INO1) 是葡萄糖二酸合成途径的限速酶，过量表达INO1，葡萄糖二酸产量达到 (107.51±10.87) mg/L，提高了2.8倍。进一步弱化竞争支路中磷酸果糖激酶 (PFK1) 的表达，最终葡萄糖二酸的产量达到 (230.22±10.75) mg/L，为进一步获得高产葡萄糖二酸细胞工厂提供基础。

Abstract:

Glucaric acid, a high value-added organic acid, is widely used in food, pharmaceutical and chemical industries. For microbial production of glucaric acid in Saccharomyces cerevisiae, we constructed a synthetic glucaric acid biosynthetic pathway by coexpressing the genes encoding myo-inositol oxygenase from mice and uronate dehydrogenase from Pseudomonas putida. Moreover, myo-inositol-1-phosphate synthase was identified as a rate-limiting enzyme in glucaric acid pathway and was upregulated, resulting in the production of glucaric acid of (107.51±10.87) mg/L, a 2.8-fold increase compared to the parent strain. Then, by repressing the activity of phosphofructokinase, the concentration of glucaric acid further increased to (230.22±10.75) mg/L. The strategy could be further used to construct cell factories for glucaric acid production.