改进莽草酸合成代谢的大肠杆菌工程化研究新进展

Improvements of shikimic acid production in Escherichia coli with ideal metabolic modification in biosynthetic pathway—A review

摘要:

摘要:莽草酸是芳香族氨基酸合成中的重要中间产物，具有广泛的药用价值，是抗流感药物“达菲”的重要合成前体。微生物发酵生产莽草酸具有许多优点，其中大肠杆菌常用于微生物大规模发酵生产应用。通过对大肠杆菌进行代谢工程改造，是构建工业化莽草酸高产菌的主要技术手段。磷酸烯醇式丙酮酸-糖磷酸转移酶系统(phosphoenolpyruvate:carbohydrate phosphotransferase system，PTS)是大肠杆菌细胞内参与葡萄糖从膜间质转运和磷酸化到胞内的主要活性转运系统，影响莽草酸合成前体磷酸烯醇式丙酮酸(PEP)的利用率。通过对PTS 系统的定向修饰和改造，调节细胞内代谢流向，提高碳源利用率，增加莽草酸前体合成量，结合对代谢途径中的特定修饰，能够构建出较为理想的莽草酸高产菌。研究显示在10 L放大体系中最佳产率可达0.36mol/mol，莽草酸浓度可达84g/L。本文针对代谢改造中莽草酸途径和葡萄糖转运系统的改造方面进行简单概述，并综述了近年来有关此方面的最新研究进展。

Abstract:

Abstract:Shikimic acid(SA) is an important intermediate in the synthesis of aromatic amino acids and has emerged as a key chiral starting material for the synthesis of antiviral drug oseltamivir phosphate(Tamiflu)．Microbial production of SA has a variety of advantages，and E．coli is commonly applied in large-scale fermentation and industrial production．Metabolic engineering is one of the main technical methods to construct the industrialized high-yield shikimic acid producing strains．Phosphoenolpyruvate: carbohydrate phosphotransferase system (PTS) is the major active transport system involved in the glucose internalization and phosphorylation in E．coli in which it affects the use ratio of PEP in cell．Modification and transformation of the PTS system could regulate the flow of intracellular metabolism and reduce the waste of PEP caused by the PTS system，in the same time，a more ideal shikimic acid producing strain can be constructed combined with the specific modifications of metabolic pathways．It was reported that in the 10 L system，shikimic acid yield reached up to 0.36 mol/mol，with concentration up to 84 g/L．This paper takes a brief overview of the metabolic engineering in the shikimic acid pathway and the transformation of the glucose transporter system，summarizes some latest researches and developments in recent years.